ESP8622 Access Point + Flask Client Example

This is a very simple code to run an ESP8266 as an access point to send and receive JSON data from clients, with a Flask code in Python to test it.

Instructions

Step 1 - Install ESP8266 boards on Arduino IDE:

• Open File > Preferences, and under Aditional Board Manager URLs, copy this: https://arduino.esp8266.com/stable/package_esp8266com_index.json
• Open Tools > Board > Board Manager, search for ESP8266 and install "esp8266" by "ESP8266 Community"

Step 2 - Upload server.ino on the ESP8622:

• After installing the ESP8266 boards, they should be available under Tools > Board > ESP8266 Boards. I'm using board NodeMCU 1.0 (ESP-12E Module) because I have an ESP-12F in my possession, which is equivalent.

• After that, just upload the code to the ESP. This video by Indrek Luuk has instructions on how to upload codes to different ESP boards using Arduino IDE: https://www.youtube.com/watch?v=_iX67plFeLs

Step 3 - Get ESP IP address:

• After succesfully uploading the program, open the Serial Monitor and copy the Access Point IP address, which will be used to make client-side requests. There is an LED pin declared in the server.ino code, which will keep blinking if no client is connected, and will be ON if a client is connected.

This is it for the server. It is running and ready to accept requests. In the route '/json1', any connected client request a JSON from the ESP, and in the route '/json2', any connected client sends a JSON to the ESP.

Flask-Client Test Example Python Code:

There are different ways to send requests. You could for example use Postman, just connect to the ESP Soft AP and send requests using the ESP IP address:

http:// + ESP_IP + /json1 -> Get Json

http:// + ESP_IP + /json2 -> Post Json

For this repo I created a small Flask server application that can be used to communicate with the ESP. To test it out, do the following steps:

Step 1 - Install Requirements:

> pip install -r requirements.txt

Step 2 - Paste ESP_IP on client.py:

• Update the ESP_IP variable with the same address copied from the ESP Serial Monitor

Step 3 - Connect to the soft AP:

• The password is at server.ino

Step 4 - Run flask code

On cmd:

> set FLASK_APP=client
> flask run

On PowerShell:

> $env:FLASK_APP="client.py"
> flask run

This should open a small page with instructions to both routes:

Open /json1 to get a JSON from the ESP:

Open /json2 to post a JSON to the ESP:

Responses on the ESP8266: