Esp8266 uart example

esp8266 uart example While the ESP8266 is often used as a ‘dumb’ Serial-to-WiFi bridge, it’s a very powerful microcontroller on its own. Send data via UART from ESP8266 (NodeMCU) to Arduino Hot Network Questions I'm doing work that should get me some money, but my parents don't pay me for the work I do and I don't like that. com This register is used to enable peripherals interrupts just like UART. All ESP boards have at least one serial port (also known as a UART or USART): Serial. This device sends and receives data from one system to another system. I have also tried serially writing data by assigning pin 22 and 23 as rx and tx of serial port and trying to send data, but is seems there is some issue. c ESP8266 SPIFFS example by iainhendry71 August 22, 2018 In this example we will look at SPIFFS , SPIFFS, or spiffs (Serial Peripheral Interface Flash File System) is a method for creating a file system in NOR-type flash memory Recommended UART (USB to TTL converter) Recommended types are those with a CH340G or a CP2xxx chip (CP2102 pictured above). Some boards like the NodeMCU have an on-board resistive voltage divider, to get an easier 0 – 3. begin(detectedBaudrate). UART Pins NodeMCU/ESP8266 has 2 UART interfaces (UART0 and UART1) which provide asynchronous communication (RS232 and RS485), and can communicate at up to 4. The structure, at_funcationType, is used to define four types of a command, e. 3 volts only. esp32 or esp8266: WOR (wake on radio) and new ESP32 shield I'm trying to get an ATmega328 and an ESP8266 to talk to each other over UART. 0 UART/SERIAL COMMUNICATION. Digital I/O. The UART interface consists of two pins: the Rx and Tx pin. 3. This is an introduction to esp32 UART. In this project, I made a simple development board fo ESP8266 with the schematic like Figure 3 and the following part list: 1. anything October 3, 2016; The Single Board Computers I’m playing with September 1, 2016; Shutting down an Orange Pi from the on board button August 30, 2016 The uart can not detect other parameters like number of start- or stopbits, number of data bits or parity. You may check out the related API usage on the sidebar. MAX5353. Temperature logger In the following example, the ESP8266 hosts a web page with a button. SSI ESP8266 AT Command Examples 2. printf("AT+UART_DEF?\r "); But my modules is answerring 'ErrorΦΛ'. Features: 1) Use ESP8266 wifi chip, extension pin layout fit both Arduino UNO and Mega2560 board. Programming NodeMCU with the Arduino IDE will hardly take 5-10 minutes. If we want to receive data with UART receive interrupt. tar. Because all operations can’t be performed on a single system. ESP8266 Interface UART 4. 3. As a first step let’s blink an LED. Project Owner Contributor ESP8266 webserver based CRO ESP8266 NodeMCU Input Output Operations. lua"), then enter node. To solve the problem with lack of serial portas on ESP8266 two variants are available: We can use Use additional converter board I2C to one UART with additional 8 GPIO on the chip SC16IS750. In this example, we use UART1 which is mapped to pins GPIO9 (RX) and GPIO10 (TX) . In the above tutorial, we discussed how to configure and use the inbuilt LPC2148 UART. Hello, is there some Examplecode for the KL82 Board to get the UART working? Is there a direct example from someone which used the ESP8266 with it? Would appreceate any help, thank you very much UART WIFI Shield is a low power consuming wifi extension working for Arduino Uno and Mega2560. At that time there was not much HTTPS support but now it seems that there is an example on how to use it with the HTTP client: Since Arduino UNO doesn’t have any network capabilities we need to device that can do networking for us, whats better than ESP8266. We must enable this bit. Or more powerful converter I2C to two UART based on the chip SC16IS752. Setup ESP8266 via serial with AT Command In order to interface ESP8266 with LPC2148 we must establish a UART serial communication between these two devices to send AT commands from LPC2148 to ESP8266 to configure the ESP8266 Wi-Fi module. , timing requirements and data framing) using widely-adapted asynchronous serial communication interfaces, such as RS232, RS422, RS485. I don’t The ESP8266 wireless WiFi modules can be driven via the serial interface using the standard AT Example AT+UART_CUR=115200,8,1,0,3 Response OK Parameters 2. The circuit below uses the ESP8266-01 module as an example. For more information about AT commands, please refer to documentation “ 4A-ESP8266__AT Instruction Set ”. serialRxTxPins = {RXPin, TXPin} so as an example, for the UART connected to the SKR WiFi header you can use 8266wifi. For example, Arduino has 6 analog pins but NodeMCU has only one analog pin. That is to say, there should be more than one client connecting to ESP8266. On the other hand, the mini UART becomes the Linux console UART for models with Bluetooth like the Raspberry Pi 3 and Raspberry Pi Zero W. Configured Arduino Interface to run AT ESP8266 - AT Command Reference 26 Mar 2015 | by fuho. I already covered How to manage multiple UARTs using ring buffer in STM32. Introduction to UART Communication In UART communication, two UARTs communicate directly with each other. Using the Arduino only for analog conversion is a bit over powered. 2) WiFi data sent through serial port, Arduino no need extra configuration. A modified version of that UART example I previously posted using modified to use this messaging method can be downloaded here:uart_test_messaging. In this case, we have two circuits. An example boot/reset message is shown here, with the reset cause indication highlighted: ets Jan 8 2013, rst cause:5, boot mode:(3,7) ets_main. I like how it is a simple check box, no need for complicated driver setup as with Raspberry Pi Zero Wi-Fi USB Adapter UART Infrastructure Required Pins. Below is the code for transmitting and receiving chars at 9600 baud. Overview This document provides AT commands based on ESP8266_NONOS_SDK and explain how to use them. lua file, open a terminal with BaudRate 115200 and enter file. UART (Universal Asynchronous Transmitter Receiver), this is the most common protocol used for full-duplex serial communication. 2 (00180008902) from AI-Tinker. ) To program an ESP8266, we use the UART bootloader the ESP8266 already contains. 3K resistor x 2 This example demonstrates simple data exchange via UART. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. In this mode you can communicate with it using a set of AT commands. h files implement driver for ESP8266 UART interface. Try TCP and UDP Pending … Download All ESP8266 related sample Code. You may also use app_uart_put, if you have first initialized the UART module, using the app_uart_init function. otb-iot uses the standard hardware serial port on GPIO 1/3 to output debug information. 1. Go to File >> Examples >> Basics >> BareMinimum then upload the sketch. com) THIS SOFTWARE IS PROVIDED "AS IS". The NodeMCU Development Board can be easily programmed with Arduino IDE since it is easy to use. 1k ohm Resistors - 3. IDLE line interrupt will notify application when it will detect for 1 character inactivity on RX line, meaning after 10us after last character. The ESP8266 peripherals include: 17 GPIOs; SPI; I2C (implemented on software) I2S interfaces with DMA; UART; 10-bit ADC; Best Pins to Use – ESP8266. ESP8266-12(E or F doesn’t matter in footprint and the only difference is memory) 2. WeMos D1 mini (esp8266), the three type of sleep mode to manage energy savings – Part 4 – Renzo Mischianti Serial Bridge Using ESP8266 One of the most well-known (appeared on Hackaday’s blog ) and well-designed projects to make ESP8266 as a WiFi-UART bridge is jeelabs’s esp-link . When the buffer is full, print them to the UART separated by TABs. We want to receive location coordinates from the GPS module. Here's what, if you don't have these things buy them : 1. . In this example it will be Flip32 running Cleanfligh 1. The terminal window shows the output from the ESP8266 UART and lets you type or paste commands for immediate interpretation and execution. So, you are left with 9 GPIO Pins. Example¶ print (uart. In this tutorial, you will learn the basics of UART communication, and the […] In our example, we’ve used a PIR motion sensor to trigger the interrupt. com. e RX pin of ESP8266 module must be connected to TX pin of the other UART device or vice versa. Just like a normal Arduino, the ESP8266 has digital input/output pins (I/O or GPIO, General Purpose Input/Output pins). UART WIFI Shield is a low power consuming wifi extension working for Arduino Uno and Mega2560. 40. While ESP8266 has the ability to automatically update its firmware over the air, the functionality in most early ESP8266 boards is broken - making updates a lot more difficult. 3V and GND). There are many sample codes that can be used within uPyCraft. 3V and connecting them to a normal UART signals without a level shifter could damage the ESP8266. Steps Result • Copy ESP8266_NONOS_SDK folder on PC to the shared directory, for example, D:\VM\share. serialRxTxPins = {4. ESP8266 UART WIFI Shield use guide. Here is how to set up the Arduino to talk to the ESP8266. 0 SDK but the problem still persists. If you supply 3. Serial is used for communication between the Arduino board and a computer or other devices. e. The connections you have written out is correct. You can use development boards like Arduino, ESP8266 WeMos D1, ESP32, RaspberryPi, STM32 Discovery to communicate with the IR controller module. 29, 4. I'm trying to send a command using printf. Parts Required. 28} or for the UART connected to the SKR TFT/Aux header. tar. ArduCAM. It would be of great help to me if someone can explain how to do serial read using esp8266. SerialDetectBaudrate. Also all sample commands will be for Linux. What it does is to swap the pins around for UART 0, and transmit messages to both UART 0 and UART 1 every second. The inputs should be debounced in any real application. When two devices are connected using a UART, the Rx pin of one device is connected to the Tx pin of the second device. "AT+TEST". Two bits of PIE1 are associated with the serial communication transmitter and receiver module of PIC18F4550 microcontroller. To work with RemoteXY the ESP8266 module must have firmware that supports AT commands not less than v0. Then, type the following AT command: AT. The board in those links is essentially a Uno with the ATMega replaced by an ESP8266, everything else, including the USB to UART circuit. ESP8266 integrates the most critical components on the board, including power management components, TR switch, RF balun, a peak power of + 25dBm of PA, therefore, ESP8266 only guarantee the lowest BOM cost, and easy to be embedded in any system. 9. For example, when uploading a binary to your ESP you have probably used UART to access the chip. When ESP8266 hosts the application, and when it is the only application processor in the device, it is able to boot up directly from an external flash. This is a continuation of my notes on the esp8266 microcontroller, you can find a complete list of my esp8266 posts here Example below presents how to configure ESP8266 to run in soft access point mode so Wi-Fi stations can connect to it. 3V logic, along with a serial terminal program. 3V range. Configuration of Interrupt Before interruptive events are sent to an interrupt controller, OR operation will be executed, therefore, only one interrupt request will be initiated by UART. 3V, for example, you will damage the chip. But in the end you want to realize projects and need examples to see how the SPI communication is done. c. h - particular IP structure and determination to work with events and timers osapi. ESP8266 default baud rate is 115200 and software UART is supports upto 9600. 5 Mbps. To be able to program the ESP8266 as stand alone module you will need any UART to USB device such as the UARTbee, or you can program the module through any Arduino board by setting the Arduino RST to GND. 3V range. Adding voice control like Amazon Echo or Google Homepod does would be a nice feature. esp8266_disconnect(): This function disconnects you module from any wifi connection that was previously connected The ESP8266 wireless WiFi modules can be driven via the serial interface using the standard AT Example AT+UART_CUR=115200,8,1,0,3 Response OK Parameters I have tested with Arduino UNO board using AT commands to communicate with ESP8266 module. The ESP8266's bigger brother - the ESP32 - has several ADC pins. This is what my own For simplicity and consistency with the previous articles (part 1, part 2, part 3) I will make the explanations while creating a demo app in an ESP8266 framework called Sming. g. docs. I am new to ESP8266. It send the command This post is a step-by-step guide that shows you how to build a standalone ESP8266 NodeMCU Web Server that controls two outputs (two LEDs). ESP8266 AT Command Examples 4. It’s not a communication protocol like SPI and I2C, but a physical circuit in a microcontroller, or a stand-alone IC. Not crossing over is a common mistake when first hooking up a serial communications device. ESP8266 ESP-12E UART WIFI Wireless Shield Development Board For Arduino UNO R3 FT232RL 3. tar. begin(9600); void loop() { espSerial You need to define the pins used by the UART (the builds provided have support for UART0 and UART3 defined, this takes the form: 8266wifi. make sure you are using at least 1. It is very easy to connect the ESP8266 module to the Arduino Due as the block diagram shows. If I understand your question correctly, you are looking for a UART RX & TX to connect the FRDM-K22F to the ESP8266 Writer board? It looks like you also need some GPIO, but I think that's less of an issue as there looks like there are a number of DI/DOs available on the FRDM-K22F. There are various methods for setting the ESP8266 into Flash Mode but not all USB/UART adapters provide all the necessary pins for automatic mode switching. 3. The ESP8266 is capable of either hosting an application or offloading all Wi-Fi networking functions from another application processor. RCIE: It enables the UART receive interrupt. The network may be protected with a password. When the ESP receives such a POST request on the /LED URI, it will turn on or off the LED, and then redirect the browser back to the home page with the button. driver/uart. You also need to ensure that the pins are in the right state. In the following example we want to send a string from an Arduino Uno to a ESP8266 NodeMCU via the UART communication line and display the string on an LCD screen. Programming NodeMCU ESP8266 with Arduino IDE. The ESP8266 has a single analog input, with an input range of 0 – 1. This ESP8266 Web Server is mobile responsive and it can be accessed with any device that as a browser in your local network. I recently posted on ESP8266: Minimum I2S code required for use I2S to accurately control output to a GPIO pin. on function. So I have an NodeMCU with an ultrasonic sensor that can communicate through UART (TTL). Out of the 17 GPIO Pins, 8 are already used for other operations like UART, SPI Flash. c, ways are delivered on how to implement a self-defined AT Command, " AT+TEST". If you supply 3. Two wires are used for power (3. Read This : ESP8266 PWM Example. Due to limitations of the ESP8266, only UART 0 is capable of receiving data. In this code I am ignoring switch debounce for simplicity. ino. Multiple Connection as TCP Server When ESP8266 is working as a TCP server, a multiple of connections shall be maintained. py to see if we can blink the LED on the NodeMCU board. Overview 1. ESP8266 AT Command Examples 4. ESP8266 integrates the most critical components on the board, including power management components, TR switch, RF balun, a peak power of + 25dBm of PA, therefore, ESP8266 only guarantee the lowest BOM cost, and easy to be embedded in any system. The ld/ directory contains two linker scripts required for ESP8266 applications. Unlike ESP32, UART0 pins of ESP8266 cannot be set to any pins, there are only two choice, GPIO15 as TX pin, GPIO13 as RX or GPIO1 as TX、GPIO3 as RX. UDP transmission UART - WiFi passthrough Here is an example that ESP8266 soft-AP create a UDP transparent transmission. 2. 5. The network may be also open, if no password is set during configuration. Hello, is there some Examplecode for the KL82 Board to get the UART working? Is there a direct example from someone which used the ESP8266 with it? Would appreceate any help, thank you very much I have been using the Arduino IDE for esp8266 coding, but would like to move to a little more powerful environment. So I need to communicate with ESP8266 via Intel Galileo but SoftwareSerial library which is used for Arduino-ESP8266 examples does not work on Galileo. The most popular ESP8266 module is the ESP-01, it has only 8 pins as shown in the picture below (with pinout): As show above, the ESP-01 board has 8 pins which are: TX: UART data transmit pin which is also GPIO1 pin # Example configuration entry esphome: name: livingroom platform: ESP8266 board: <BOARD_TYPE> Many boards have a pin numbering for the exposed pins that is different from the internally used ones. Originally used with Arduino boards to WiFi-enable hardware projects, it soon became a cheap standalone Arduino-compatible development board. h> #include <SoftwareSerial. If you want to put it back in the state as it was before writing init. 3V, for example, you will damage the chip. 3 uses an Ai-Thinker ESP-12S module with a WinChipHead CH340G USB-to-serial bridge chip. So I’m thinking about these commands: Basic commands for settings up ESP This tutorial shows how to debug the ESP8266 firmware using the UART GDB stub provided by Espressif without any JTAG hardware. UART (or for Arduino often also called Serial) usually consists of 2 pins: TX: This line is used to send data to the device at the other end. 4. Its an ESP8266 WiFi module with all the extras you need, ready In certain cases we need to use more than one Serial port in the case of arduino, I use the arduino mega 2560 which has 4 serial ports including the programming port, in the case of arduino’s as the nano has a single programming port and as a solution Have created the softwareserial library, given the incompatibility of certain functions the softwareserial library for arduino does not work When connected from computer to esp8266 using python (terminal on 1001) i send for example uart. This project represents typical ESP8266 TCP Server application maintaining basic functionality to receive and process sample single-byte data from corresponding TCP Client side. This could be easily done using an ESP8266. The structure, at_funcationType, is used to define four types of a command, e. The ESP8266WebServer library allows you run an ESP8266 as a basic webserver and access point. It's called USB to TTL serial adapter (for example, USB adapter for ESP8266 ESP-01, FT232RL FTDI USB to TTL Serial Adapter, CP2102 USB to TTL UART converter). Without using this trick, the ESP8266-01 does not have any free pins to use as an input if you are already using pins RX/TX for a UART connection. Best regards, Karl You can find allot of projects examples over the internet, I for example, found great ideas on arduino. For example, in the above diagram, one UART device is a TM4C123G Tiva launchPad and the other device is a GPS module. Using the Arduino only for analog conversion is a bit over powered. The transmit and receive signals of the UART on the Arduino and UART on the ESP-05 cross over – i. Using the code in the previous example, we can request the time, and save some sensor values to a file. The esp8266 SDK manual and examples are pretty poor. Default settings are 9600 kbps baudrate, 8 bit data, 1 stop bit and no parity. However, on my first attempt to get a project working, I'm running into a lot of issues trying to get everything compiled and linked. Level shifting on the UART and reset pin, 3. the example of \ESP8266_NONOS_SDK\examples\at\user\user_main. If you get an UART with settable 5V/3. 3V range. It supports UART, SPI, and I2C interface. 2. 2 2 TCP_Client_Single trail, if you have finished that part, you could upload the sketch below, and send commands "H","L" to open up or turn off it on your computer. In the attached minimal example, I have an LED on pin 16 (B2) that should start on and do a slow blink to show data was sent / received. Some boards like the NodeMCU have an on-board resistive voltage divider, to get an easier 0 – 3. Different firmware versions may behave differently. 3V out, 500mA regulator (you'll want to assume the ESP8266 can draw up to 250mA so budget accordingly) Two diode-protected power inputs (one for a USB cable, another for a battery) Two parallel, breadboard-friendly breakouts on either side give you access to: 1 x Analog input (1. The detection itself does not change the baudrate, after detection it should be set as usual using Serial. The ESP8266 is a low cost Serial-to-WiFi module that interfaces nicely to any microcontroller. c, ways are delivered on how to implement a custom, user-defined AT Command, " AT+TEST". Sample code. For this tutorial we are only going with the uart interface. This video described ESP8266 UART ECHO Test. ESP8266 offers a complete and self-contained Wi-Fi networking solution, allowing it to either host the application or to offload all Wi-Fi networking functions from another application processor. A simple guide to sending data from one ESP8266 to another over Wi-Fi using an ad-hoc, device to device network, without using a wifi router. Use a setup similar to ADCT0ATrigger. I have configured the UART pins P6. By checking interrupt status function UART_INT_ST(uart_no), software will be able to process several interruptive events (composed by ESP8266 has two UART ports, UART0 and UART1. Cheap UART converters based on FT232RL (or quite probably its clone) seem to be good choice for programming interface as they have switchable UART voltage levels (5V, 3. Preambles Example AT+UART=115200,8,1,0,3 Response OK Parameters <baudrate> Baudrate range: 110 to 115200*40 (4. A simple example is. Feather is the new development board from Adafruit, and like it's namesake it is thin, light, and lets you fly! We designed Feather to be a new standard for portable microcontroller cores. [email protected] In the second example we build up a SPI communication between an ESP8266 NodeMCU as master and an Arduino Uno as slave. UART stands for Universal Asynchronous Receiver/Transmitter. Using Explore Embedded Libraries. ESP8266-12(E or F doesn’t matter in footprint and the only difference is memory) 2. c and driver/uart. To know more about ESP8266 AT commands follow the link. This ESP8266 IC based ESP-01 variant is a WiFi module which can give your Arduino or other electronic projects WiFi capabilities and can even be used on its own by reprogramming the ESP8266 MCU! Overview. With some UART cables a wire has to be soldered accordingly. In this chapter, we’ll look at the non-Wi-Fi specific functions of the ESP8266. This may seem very basic but it ensures everything is working as it should be. 11bgn Smart Device 2 Technology Overview ESP8266 offers a complete and self-contained Wi-Fi networking solution, allowing it to either host the application or to offload all Wi-Fi networking functions from another application processor. If MCU is connected to the PC, you can test the example from the mikroC PRO for PIC32 USART communication terminal, launch it from the drop-down menu Tools › USART Terminal or simply click the USART Terminal Icon . When ESP8266 hosts the application, and when it is the only application processor in the device, Making a ESP8266 and A-Star / Arduino Leo combine board I used inDesign, overlay the lines right on top of the image; Design a Web Interface to control the Robot I used Jquery library to do the get request and animation. org // /* Author: Steven Prickett (steven. A modified version of that UART example I previously posted using modified to use this messaging method can be downloaded here:uart_test_messaging. Here is a simple Arduino blink example which you can use to test the esp module with the built in LED: /* ESP8266 Arduino Blink by Simon Peter Blink the blue LED on the ESP-01 module This example code is in the public domain The following are 16 code examples for showing how to use machine. In this tutorial we are going to connect ESP8266 with USB to UART converter. Features: 1) Use ESP8266 wifi chip, extension pin layout fit both Arduino UNO and Mega2560 board. The ESP8266's bigger brother - the ESP32 - has several ADC pins. The sending code in the 1 second call-back function is: ESP8266 Peripherals. Copy all files in folder "at" to folder "app" in ESP8266_NONOS_SDK if users need to compile AT. It comes in the familiar Arduino Shield shape, and should work with any similarly-sized Arduino Basic uPyCraft Example. The ADC (analog to digital converter) has a resolution of For example, the NodeMCU Development Kits use Ai-Thinker modules, the Adafruit Feather HUZZAH uses an Ai-Thinker ESP-12S module with a SiLabs CP2104 USB-to-serial bridge chip, and the WEMOS D1 Mini version 2. zip. 3v. I will write more about it in the chapter Connect ESP8266 to UART-USB adapter. This is an example to show how to get data from a remote Arduino via LoRa. 3 Choose Serial Port of ESP8266, click Flash to burn firmware; 4 Wait for done. The ESP8266's bigger brother - the ESP32 - has several ADC pins. WiFiTelnetToSerial - Example Transparent UART to Telnet Server for esp8266: Don’t connect these pins directly to an RS232 serial port; they operate at +/- 12V and can damage your ESP8266 board. MicroPython ESP32 minimal UART example This example shows how to use UART on the ESP32 using MicroPython. MAX5353_4C123. 2. If anything is using UART, it can also use ESP8266 as serial bridge over WiFi. SPI; I2C; UART; Serial I’ve not been using the ESP8266 in a while but at the time I’ve written this tutorial, trying to reach a HTTP Secure endpoint didn’t work. 3V set it to 3. 0V max) ESP8266 is the name of an infamous WiFi module that is a system on a chip (SoC) developed by Espressif Systems, a company based in Shanghai. The ESP8266 module comes with AT firmware which allows us to control it with AT commands through serial interface (RX and TX pins). Next, open the serial monitor. Can anyone suggest how to approach or give me some example programs. Analog input. Connect PC to ESP8266 softAP. The Espressif SDK version that was used is 1. Copy the ESP8266_NONOS_SDK to be compiled to the shared folder. Practicle example: Imagine we received 10 bytes at 115200 bauds. getconfig(0)) -- prints 9600 8 0 1 for 9600, 8N1 Serial-to-WiFi Tutorial using ESP8266. transmit from one UART connects to receive on the other and vice versa. However, that would be a separate tutorial so hopefully you’ll come back We can also connect the TXD and RXD signals to a USB-to-UART circuit, however the RXD and TXD signals on the Olimex board have levels of 0 to 3. After connecting JTAG and optionally UART your board will look like this: LuaLoader is a Windows program for uploading files to the ESP8266 and working with the Lua serial interface. The process should be similar for any serial chip that you want to interface with your MSP432 though! This app sends1) ESP8266 device meta and state of two GPIO pins to AWS IoT (which can also be remotely controlled using AWS Lambda and API Gateway) each seco The Arduino Uno R3 only has 1 HW UART that is connected to the on board USB - UART chip. Breadboard Power Supply module - optional but makes life very easy. Despite the fact that the ESP8266 was designed as a serial-wifi device, I’ve recently found the need to extend the ESP’s the UART support using an another IC, to allow myself to reliably interface to a heat meter supporting the M-Bus protocol. Grove - UART WiFi is a serial transceiver module featuring the ubiquitous ESP8266 IoT SoC. If we run a server as well, we can show this data in a pretty graph in a webpage. I have created a very simple program to demonstrate the above two options. The following picture shows the connection between the Arduino and ESP8266 microcontroller and the LCD display. UART Bus¶ UART is a common serial protocol for a lot of devices. I am new on ESP8266 and I have a Intel Galileo Gen1 and no USB – TTL converter or an Arduino. Using the Arduino only for analog conversion is a bit over powered. This is called a UART, or Universal Asynchronous Receiver / Transmitter. The code is using ESP-IDF and can be found on GitHub, click here. And it is necessary to program the chip. print() at the same time) Note that this sketch uses LED_BUILTIN to find the pin with the internal LED */ void setup() { pinMode (For example: switch the light on, turn on the radio, control the heating system…). The ESP8266 is a highly integrated chip designed for the needs of a new connected world and is the go to choice for IOT. The ADC (analog to digital converter) has a resolution of ESP8266 Teensy Time It isn't often that a new chip on the block causes a stir like the ESP8266 has! What is it? It's a WiFi interface. UART0 (TXD0, RXD0, RST0 & CTS0 pins) can be used for communication. In today’s blog post I will show you how to implement a web server with ESP8266, using one WiFi3 Click and one USB-UART click from MikroElektronika. ESP8266 application subject Hello everyone, ESP8266 with AT commands software from Espressif is now more stable than every, so I’m thinking to make a “strong” AT commands parser library for STM32 series of microcontrollers. The Esp8266 is a 3. I will present to you a reference of all known AT commands that ESP8266 supports, explain what they do and how to use them. NodeMCU can be powered using Micro USB jack and VIN pin (External Supply Pin). For example, ESP8266_send_string(“AT/r/n”) will send the command “AT” to the ESP8266 module. Here is an example showing how TCP server is realized when ESP8266 is working in softAP mode: • Set WiFi mode: ESP8266 802. The PIC16F887 microcontroller has one USART module, this module can be used as USART or UART depending on the configuration of some registers related with the module. UART: Universal Asynchronous Receiver/Transmitter The compiler used in this project is Microchip MPLAB XC8 (MPLAB X IDE with MPLAB XC8 compiler). For ESP8266 station, it can execute UDP transparent transmission in the similar way. Also os_printf also appears to stop printing once I run uart_config. I did start to implement a driver to communicate with an ESP8266 board using AT commands over UART. 0. Esp8266 WebServer using STM32 HAL Description. ) And currently, I've moved on to Arduino/esp8266. 12 via MSP protocol, but it will work for MAVLink too; ESP8266 with flashing device UART Pins NodeMCU/ESP8266 has 2 UART interfaces (UART0 and UART1) which provide asynchronous communication (RS232 and RS485), and can communicate at up to 4. Conclusion As an example of using the driverlib to configure a serial module, I'll step through the process of configuring the eUSCI_A2 module for UART with a baud rate of 9600 so that it can talk to my ESP8266 chip. If you see “OK”, that means the ESP8266-01 is working. 1 pins as UART comm for this module. The kaa/ directory is where you put the generated Kaa C SDK tarball and unpack it. At the physical level it consists of 2 lines: RX and TX. You can't program it in the MPLAB environment. Read This : ESP8266 PWM Example. Things we need. For ESP8266 station, it can execute UDP transparent transmission in the similar way. This means you can send Linux commands from your PC to the Raspberry Pi on this UART. Further data processing also consts of simple scenario to set GPIO12, GPIO13, GPIO14 output levels according to 3 less-significat bits from input byte of data. This is a continuation of my notes on the esp8266 microcontroller, you can find a complete list of my esp8266 posts here Packed with a 32-bit RISC CPU running at 80 MHz, a fully integrated WiFi radio with TCP/IP protocol stack, serial peripherals (I2C, SPI, and UART), an ADC channel, and general purpose I/O pins, the ESP8266 is the most integrated and affordable WiFi solution available in the current IoT market space. More about functional pins in chapter Pinout. Analog input. I discussed about pins, code and sample connection to an external arduino. First of all, I apologize in case I make some mistakes posting this question. This is a continuation of my notes on the esp8266 microcontroller, you can find a complete list of my esp8266 posts here Hi, I have some data which i want to send from nrf51-dk to ESP8266. A full list of ESP8266 AT commands is provided at the end of this post. Do not use cheap converters with a FTDI232 chip! The FTDI232 might be one of the most faked chips at all. Make sure to set the baud rate to default, which is usually 115200. 0V. If you are using the ESP8266-01, for example, you need to select “Generic ESP8266 Module”. When the button is pressed, the browser sends a POST request to /LED . tar. Actually, this project is far beyond being a simple serial bridge as it also manages MQTT client pub/sub and REST HTTP requests in order to connect the MCU to the TX and RX serial connections ‘crossover’ is a must: i. Hi again, well, I have been trying with the lates ESP8266 1. I just want to suggest two alternatives: Use an external analog to digital converter IC. I think it can be the problem of baud rate mismatch. Using the Arduino only for analog conversion is a bit over powered. However, a word of caution -- it is highly undocumented (primary reason for writing this document), and more importantly, it is frequently updated and not backward compatible. It is a single LSI (large scale integration) chip designed to perform asynchronous communication. c to gather ADC samples into a buffer. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. UART(). You must have a knowledge of that, if you want to understand this one. Eclipse seems to fit the bill. One important thing to notice about ESP8266 is that the GPIO number doesn’t match the label on the board silkscreen. This is to make sure that no program is running on the Arduino board. 3V regulator powering the chip; Btw… you can get USB to TTL-level UARTs super cheap, check out electrodragon for ones ESP8266 WiFi Module. I ask kindly there is a complete project, including everything (include, ini) working that if i upload from boot usb-uart With the ESP8266 conenected, run the following command on your target board: # slattach -p slip -s 115200 /dev/ttymx2& This will attach the serial line device that is, in this example, on UART_C (mapped as /dev/ttymxc2, using the Colibri iMX6DL) with a baud rate of 115200 baud using the SLIP protocol. Now we will see how to use the ExploreEmbededd UART libraries to communicate on all the four UART channels. (Because "higher level" C libraries are nice, this also lets me call lower level direct esp8266 functions when needed. ESP8266 BOM is the only external resistors, capacitors, and crystal. Use an ESP8266 to bridge that serial port gap! November 15, 2016; Using Amazon Echo and ESP8266 to add voice control to …. But if you still insist in using the generic ESP8266 module, there is a way to use it with the Arduino core mentioned above without using an Arduino. It is compatible with all versions of Windows from Windows 95 to Windows 10. 0. Esp8266 can be programmed OTA(over the air) and by uart interface. ArduCAM ESP8266 UNO Board User Guide 3 www. A UART’s main purpose is to transmit and receive serial data. Background ESP8266 firmware update. In order to boot the ESP8266 in Flash Mode, the GPIO-0 pin must be set low (GND) and the CH_PD pin must be set high (VCC). The ESP8266 will switch BaudRate to 115200 after power on. This is usually the stock firmware on those devices when you purchase them. Before you begin, connect the TXD and RXD signals on your ESP8266 board to a USB-to-UART circuit, however the RXD and TXD signals on the Olimex board have levels of 0 to 3. AI-Thinker AI-Link. The ESP8266 has a single analog input, with an input range of 0 - 1. 3V only IO Arduino Uno R3 is 5V IO Solution: Use simple R divider… Remember to select the board you are using in the Arduino IDE. restart(), then close terminal and open again with BaudRate 9600. I dont understand about the basics of the uart. My problem is that the LoLin ESP8266 board use the same Tx0 and RX0 UART port to communicate with the embeded CH341 USB/UART chip. Set WiFi mode. The Wi-Fi network established by the soft-AP will be identified with the SSID set during configuration. In the example of \ESP8266_NONOS_SDK\examples\at\user\user_main. I have one of those controllers combined with a touch sensor and use it to control light and music when I am in my bed. Detection is very fast, it takes only a few incoming bytes. I just want to suggest two alternatives: Use an external analog to digital converter IC. I've been googling around and couldn't find a straight forward example of just receiving a string through UART. The module can be connected via the Arduino board, or through a USB-UART adapter. I'm writing from Argentina and I'm trying to send data from ATmega32 (via UART) to ESP8266, and ESP8266 re-transmits this data on the air (via WiFi). The ESP8266 WiFi Shield finds a middle ground between the Module and the Thing -- it comes pre-flashed with an AT-command firmware, so it can be controlled by any UART, but it also breaks out and provides command access to all of the ESP8266's I/O. Again this leaves the TX / RX pins available for Serial debugging or use as other I/O. Some boards like the NodeMCU have an on-board resistive voltage divider, to get an easier 0 - 3. To check the version of firmware, as well as to update the firmware, need to connect the module to a computer via serial port. If you like programming the ESP32 and ESP8266 boards with MicroPython, and you want to learn more, please take a look at the following resources: Sample loop() Code for Relay Manual Over-ride. The problem is that some data is missing SOMETIMES, and sometimes it is sent OK. The PL011 UART is the main UART for models without Bluetooth feature and is tied directly to the Linux console output. To be more precise it's a WiFi interface suited to microcontroller applications, IoT etc & it has an integrated TCP/IP stack. I tried my best to wr… Contribute to esp8266/Arduino development by creating an account on GitHub. I also previously used a UART hack to use serial output to control an IR led . To ease out the task of programming esp8266, I bought this: ESP-01 ESP8266 Programmer CH340G Chip USB WiFi Wireless UART GPIO0 Adapter. 2) WiFi data sent through serial port, Arduino no need extra configuration. With the ESP8266 connected, run the following command on your target board: # slattach -p slip -s 115200 /dev/ttymx2& This will attach the serial line device that is, in this example, on UART_C (mapped as /dev/ttymxc2, using the Colibri iMX6DL) with a baud rate of 115200 baud using the SLIP protocol. Install the ESP8266 serial library to your IDE. Eg. For more information about AT commands, please refer to documentation “ 4A-ESP8266__AT Instruction Set ”. Link where to buy parts:ESP32 - https://amzn The ESP8266 WiFi module and the microcontroller can be interface through UART and with the help of a wide range of AT Commands, the Microcontroller can control the ESP Module. Anyone can then adapt this tutorial to any microcontroller used to control the ESP8266. So, on the ESP8266 board with USB interface there is no any free UART. esp8266_isStarted(): It is used to check if the PIC can communicate with the ESP module. 3V and connecting them to a normal UART signals without a level shifter could damage the ESP8266. UDP transmission UART - WiFi passthrough Here is an example that ESP8266 soft-AP create a UDP transparent transmission. As I use the USB port to program the board and also retrieve some other data, I think having these 2 devices on the same UART is the source of my problem as it sometime doesn't respond as espected. Then run: ESP8266 must be powered with 3. WiFiTelnetToSerial - Example Transparent UART to Telnet Server for esp8266 . Each byte at 115200 bauds takes about 10us on UART line, total 100us. I agree with @Offer that using UART is the simplest solution to connect the devices. This project adds to Sprite_tm's webserver, and hosts a web page that among other things, plots data from a uart-DAQ using jquery. The sample code is here, ESP8266_01pinMagic_1. The ESP8266 accepts many AT commands but today we are only going to use some of the most common ones. e. ino is a full example of usage. A modified version of that UART example I previously posted using modified to use this messaging method can be downloaded here:uart_test_messaging. With integrated TCP/IP protocol stack, this module lets your micro-controller interact with WiFi networks with only a few lines of code. Which means it won’t work with any libraries that access Settings that we’ll have to program include, for example, the SSID and password for the wifi network the module will be connected to. Alter the makefile to look for the “uart. This is a continuation of my notes on the esp8266 microcontroller, you can find a complete list of my esp8266 posts here USB to TTL UART Adapter communicating with ESP8266 and providing 5V to the 3. The code is as follows: #include <SoftwareSerial. In this tutorial, I will use Tera Term to communicate with the WiFi3 click. There an example uart. You can use the ESP8266 as a standalone microcontroller, it has 16 GPIO pins, SPI, I²C , UART and ADC pins, Or you can send it standard AT command from the microcontroller via the UART module. UART0 has both TX and RX pin, to send AT commands and receive response. To begin, establish the connection between the device used to program the ESP8266 by following the table below. However, it seems to hang on the gets() call, as the LED never comes back on. h> SoftwareSerial esp8266(2,3); // make RX msp430g2553 line is pin 2, make TX msp430g2553 line is pin 3. Im using an Arduino UNO to read data from some sensors and I’m sending that data to an ESP8266 through UART . I agree with @Offer that using UART is the simplest solution to connect the devices. i could not see much of example codes for the same. Initially, this tutorial was written in Portuguese here in Brazil. Connecting ESP8266 to MSP430 thorough UART? So today in my Alpha schematic review my instructor basically grilled us, but when he got to the wifi module connected through UART he asked us if the ESP8266 is DCE or DTE, to which he proceeded to make me fell absolutely stupid. The connection can be established through any of the following protocols. - Thu Nov 05, 2015 2:54 pm #33129 Hi, My first post here I didn't find the answer on the forum or anywhere else, hope someone can help. 3. 1. 5 Mbps. ESP-01 adapters ESP8266 ESP-01 module The ESP8266 wireless WiFi modules can be driven via the serial interface using the standard AT Example AT+UART_CUR=115200,8,1,0,3 Response OK Parameters Example 1. i have tried Ble UART central example to write data serially but doesn't achieve any result. This video described ESP8266 UART ECHO Test. Use the OSOYOO UART LoRa Wireless Module to Control an LED Remotely. 3. Mount the shared directory to the virtual machine. remove("init. com‌,. In an ESP8266, as in many other microcontrollers, a bit of the chip’s hardware is dedicated to sending and receiving serial data. To use this example, you'll need something to generate the UART data. ESP8266 AT Instruction Set 1. Common Registers Following on from the FTDI + ESP8266 post, if you do not have a FTDI serial adaptor you can use an Arduino. Example callback function displays few basic information like packet channel, length, RSSI or MAC addresses. A Universal Asynchronous Receiver/Transmitter (UART) is a hardware feature that handles communication (i. AT firmware of the ESP8266 WiFi module on ESPWiFi shield allows users to communicate with the module using UART communication. 2 version AT firmware (run cloud update first) Turn on the APP "AI-link" in your android cell phone; enter the wifi SSID and password and click "start" I agree with @Offer that using UART is the simplest solution to connect the devices. Sometimes, when the WIFI connection is lost (switching off the router for example), and the WIFI network comes back, the ESP8266 module does not recover, and from that moment on, it will NEVER recover. espSerial. 0 and P6. UART0 (TXD0, RXD0, RST0 & CTS0 pins) can be used for communication. With integrated TCP/IP protocol stack, this module lets your microcontroller interact with WiFi networks with only a few lines of code. Updating ESP8266 Firmware. flot. This is the Adafruit Feather HUZZAH ESP8266 - our take on an 'all-in-one' ESP8226 WiFi development boardwith built in USB and battery charging. If you don't have the 0018000902-AI03 firmware version, make sure you change the baud rate and Module Name in the code examples below. 3v device and so I am using a voltage divider to bring the Arduinos 5V down to 3. AT+CWMODE=3 // softAP+station mode Response: OK 2. I need a second one to interface with my recently purchased ESP8266 ($4 Wifi module). 3V needed for ESP8266, even more with external regulators) and all FTDI pins broken out. #define MAX_SRV_CLIENTS 1. I an using a 5V Arduino Nano which of course is 5V. I just want to suggest two alternatives: Use an external analog to digital converter IC. It communicates on RX and TX. You can use this example right from your desk! For example esp8266_connect(“home”,”12345678”), will allow your module to connect to the wifi signal named home whose password is 12345678. For example, D0 corresponds to GPIO16 and D1 A common use for IoT devices like the ESP8266 is monitoring sensors. I'm making my first foray into the Eclipse CDT environment with a MinGW GCC tool The sample code below shows how you can send to UART 1. So two are more microcontrollers or microprocessors can be combined to form a required embedded system. I want write program for communicating with ESP8266 module on UART. We've used a GPS! Note that the GPS will give you UART data without getting a fix on your location. h are C: \ Espressif \ ESP8266_SDK \ include \ ets_sys. Good morning we wanted to start implementing on my esp8266-12 the RTOS operating system, but i was not able, because after uploading with usb-uart (boot) on my ESP, if I go to check it does not work, indeed the serial continues to transmit data which for me have no meaning. I just want to suggest two alternatives: Use an external analog to digital converter IC. c” file under the “driver” directory; About serial connections. This approach was a bit hacky though, requiring a few transmissions of the UART IR signal to get proper reception. ESP8266 ESP-12E UART Wireless WIFI Shield TTL Converter Uncomplicated: This guide is intended to help people who have purchased the ESP8266 ESP-12E UART Wireless WIFI Shield TTL Converter and do not know how to use it with Arduino. 3V. First question: Is the command right? or i need to send something before or after command? The ESP8266 Arduino core is very simple to use and contains a lot of example sketches that will make your work faster. ESP8266 Sketch 1: Blink an LED. The ESP8266 is an extremely versatile chip that can do a whole lot more than just sit on an ESP-01 module! The simple ESP8266 Blinking LED project was one of my first goals when getting started with developing with this chip because it assures you that you can compile a dirt simple program – which is quite a feat. Anyone have any sample code that fall's into uart0_rx_intr_handler. TM4C123G Tiva C development board will send data requests to the GPS module through Tx pin and GPS module will receive it through Rx pin. All the files in folder "at" should be copied to theto folder "app" in ESP8266_NONOS_SDK if users Okay I assume you've just bought the ESP8266 ( just the module ), it's arrived but now what. 3V, for example, you will damage the chip. 5V FTDI USB to TTL Serial Adapter Module for Arduino Mini Port Arduino IDE class UART – duplex serial communication bus¶ UART implements the standard UART/USART duplex serial communications protocol. Application may react on this event and process data accordingly. g. Presented sniffer requires a callback function that will process all received promiscusous packets. What I've found using software serial is that it can push 115200 baud well enough to send commands to the device (though I wouldn't build an application that depends on it) but it can This quick-start example shows how you can create a UART device for communicating with hardware serial devices. The board used in this tutorial uses the stock firmware version . UART: serial communication WiFi : why I bought the ESP8266 in the first place. To connect the ESP8266 to a computer and configure its settings, we’ll need a USB to serial adapter with 3. The ESP8266's bigger brother - the ESP32 - has several ADC pins. ESP8266_send_string(): This function is the string version of _esp8266_putch(). So we can either use a USB to TTL serial adapter (converter) or use an Arduino to communicate and upload the code to the ESP8266. Environment requirements: you need to have UNO and ESP8266/NodeMCU; you would also need a 5v to 3v3 level converter to convert the UART signal levels. MAX5353_4C1294. zip. If you supply 3. ESP8266, in it’s default configuration, boots up into the serial modem mode. For ESP8266 station, it can execute UDP UART-WiFi passthrough transmission in the similar way. • Copy ESP8266_NONOS_SDK\examples\at folder to the directory D:\VM\share \ESP8266_NONOS_SDK, as shown in the figure on AT+UART_DEF=<baudrate>, <databits>, <stopbits>, <parity>, <flow control> Example: AT+UART_DEF=115200, 8, 1, 0, 3 I have used these and can confirm that they work. Hi [email protected] Data files, except user_config. The unit of communication is a character (not to be confused with a string character) which can be 8 or 9 bits wide. 0V. Program 7. The ESP8266 reset cause is a part of the boot message string that is printed via the UART port with the default baud rate every time ESP8266 is reset (including power-on-reset). PIC18f45k22 XC8 I have set my uart to 115600. It can send one complete string to the ESP8266 module. Grove - UART WiFi is a serial transceiver module featuring the ubiquitous ESP8266 IoT SoC. 3. You could also just use a trimpot as a voltage divider. c // Brief desicription of program: // - Initializes an ESP8266 module to act as a WiFi client // and fetch weather data from openweathermap. In this example, we will use blink. ESPHome tries to map the silk-screen pin numbers into the internal pin numbers with a few boards, but for generic ESP8266 boards it is often required Hello , again ! I think I’ve run into a problem with my project and I need a bit of guidance . NodeMCU ESP8266 workshop presentation at Melbourne HackerSpace on 2015-03-11. To program an ESP8266, we use the UART bootloader the ESP8266 already contains. Have you seen the UART example? It demonstrates how to initialize and use UART with your nRF52832 device. UART1 only supports TX pin to print debug log. Posted on November 29, 2014 by petertchang Tagged Arduino ESP8266 Serial Port Communication CommentsNo Comments on Arduino SW UART example Arduino SW UART example The Arduino Uno R3 only has 1 HW UART that is connected to the on board USB – UART chip. I just moved on and use uart_sendStr() (found it from some other websites. 0V. 608 Mega) <databits Starter module supports UART communication. h and driver / uart. Pin Reset has to be HIGH during normal operation. To send data from Arduino UNO to ESP8266 we will use UART. Now let’s run a sample code to check whether our connection to the ESP8266 is working. I am faced with a strange behavior of esp8266-01, and i would like to ask you if you had any similar behavior when you implement the web server. I built this out a bit so I could read serial data from the circular buffer. 2. This is an alternative approach to the port of MicroPython to this board and uses the default firmware on the ESP8266. If there well be an interest, I can do a generic library (like FATFS) to make usable on others microcontrollers too. FT232 is a versatile adapter, its function is to transfer data from usb to uart. Flight controller with free UART serial port. But the example presented can also be used to detect a button press, for example. com 3 Pin Definition Figure 2 ArduCAM ESP8266 UNO Pin Out Note that the SD/TF card CS pin is shared with UART TX signal, so the UART I have been using the Arduino IDE for esp8266 coding, but would like to move to a little more powerful environment. c knocking around, but the receive code is incomplete. The Tx pin is used to transmit data. 3) wifi and searial port config through web page. UDP transmission UART-WiFi passthrough Here is an example that ESP8266 softAP create a UDP UART-WiFi passthrough transmission. 3K resistor x 2 ESP-link for wireless UART. 3) wifi and searial port config through // esp8266. MAX5353 12-bit DAC. In this project, I made a simple development board fo ESP8266 with the schematic like Figure 3 and the following part list: 1. Challenge 1: Voltage Difference ESP8266 is 3. These examples are extracted from open source projects. The AT Commands of the ESP8266 WiFi Module are responsible for controlling all the operations of the module like restart, connect to WiFi, change mode of operation and so See full list on embetronicx. ESP8266 Development Module (for example based on ESP-12x) ADC, PLL, Timer0A, UART. 1. For example in my picture, when I type “123” in Serial Monitor COM16, it will be sent over and appear at Serial Monitor COM5. cc projecthub. AT command set is divided into: Basic AT commands, Wi-Fi AT commands, and TCP/IP AT I agree with @Offer that using UART is the simplest solution to connect the devices. when I send the data to the browser and I close the connection on channel 0 for example, then the module opens a new channel connection. Not only can the ESP8266 connect to a WiFi network and interact with the Internet, but it can also set up a network of its own, allowing other devices to connect directly to it. "AT+TEST". 2. //how many clients should be able to telnet to this ESP8266. We already set up the uPyCraft and flashed firmware onto our ESP8266. 4. The first one is a communication between the Arduino Uno as master and an Arduino Mega as slave. This example demonstrates how to turn the ESP8266 into an access point (AP), and serve up web pages to any connected client. Wifi Module Esp8266 I'm trying to connect a wifi module. UART objects can be created and initialised The modules don’t have a UART-USB adapter built into the board. ESP8266 to RS485 example Showing 1-10 of 10 messages. 1. The ESP8266 has a single analog input, with an input range of 0 – 1. h - timers and some system functions such os_strcat, os_memcpy, os_delay_us etc. So something like : #include <Arduino. write(0,”1,255;”) and “1,255;” is sent to arduino and when arduino send something back to PC i send it like “print”123″” and 123 is printed on terminal/sent to python. It can be hardware or Software Serial. h> SoftwareSerial espSerial(5, 6); // I made the pin 5 = Rx , 6 =Tx . 3V 5. You can check how to connect debug USBtoTTL device on “WeMos D1 mini (esp8266), debug on secondary UART“. Application This is a little application which is built on the 4. ESP8266 to RS485 example: farbod Shajjarian: in the last setup (esp gateway + arduino peer (uart)) TTL UART inputs, connects to external (MCU, PC) TXD outputpin. If you are lazy, just copy the code below: /* ESP8266 Blink by Simon Peter Blink the blue LED on the ESP-01 module This example code is in the public domain The blue LED on the ESP-01 module is connected to GPIO1 (which is also the TXD pin; so we cannot use Serial. The ESP8266 WiFi Module is a self contained SOC with integrated TCP/IP protocol stack that can give any microcontroller access to your WiFi network. Maker module combines our Starter module with a widely popular Wemos D1 Mini So unfortunately it is printing garbage characters. The Rx pin is used to receive data. A modified version of that UART example I previously posted using modified to use this messaging method can be downloaded here:uart_test_messaging. If you looked at the ESP8266 NodeMCU Pinout, you will realize that not all the GPIO Pins of the NodeMCU Board can be used as simple GPIO Pins foe Digital Input and Output operations. esp8266 uart example