Micropython Tutorial for Wemos D1 Mini

All examples are for Wemos D1 Mini, WS2812B RGB Shield (NeoPixel) and DHT Pro Shield.

Student prerequisities

• Python knowledge
• Micro USB cable
• Python 3 installed
• Python IDE installed
  • https://code.visualstudio.com/
• Git client (optional)

Lessons

Computer setup

• Connect to internet
• Install serial terminal
  • Windows: Putty
  • Linux, Mac: Use screen tool
• Install ampy, install instruction
  • Add ampy to PATH
• Install drivers for CH340 (Mac, Windows < 8.1)

First script

Interactive prompt using serial terminal

Baudrate: 115200

Control LED on ESP8266 chip. LED is connected on pin 2 to VCC. You control ground (0 - on, 1 - off).

import machine
pin = machine.Pin(2, machine.Pin.OUT)
pin.value(0)
pin.value(1)

Upload script using ampy

Scrip name: 101.py

Close interactive prompt

Example for Windows. Use your serial port number.

ampy --port COM14 run 101.py

Example for Linux and Mac. Do not forget to use full path to your serial port.

ampy --port /dev/ttyUSB0 run 101.py

File system

Documentation ampy

Startup scripts

• boot.py
• main.py - runs automatically after start

ampy --port COM4 put main.py

ampy --port /dev/ttyUSB0 put main.py

DHT22 (DHT11) and RGB LED

Using hardware drivers

How it works with pins

Read temperature and humidity dht.py

What is it Neopixel LED and how it works

Control Neopixel RGB LED neopixel.py

Create simple thermometer using RGB LED and DHT11 - temperature is showed using colors (for example red hot, blue cold)

HTTP protocol

How it works

GET vs POST

HTTP Headers

SSL

Internet

Explain Wi-Fi modes - access point vs. client

Connect to local Wi-Fi wifi_connect.py

Download website http_test.py Connect to Wi-Fi first!

ThingSpeak

Create ThingSpeak Account

Create Channel

Send data from DHT11 to channel

Server

How to use Access point mode

Run this code to find mac address of your board.

import network

wlan = network.WLAN(network.STA_IF) # create station interface
wlan.active(True)       # activate the interface
print(":".join(map(lambda x: "%02x" % x, wlan.config('mac'))))

Open list of available Wi-Fi and connect to Wi-Fi named MicroPython-xxxxxx where xxxxxx is part of MAC address. Password is micropythoN. IP addres of board is 192.168.4.1.

Create simple web server showing current temperature

Crete web server controlling RGB light

Firmware update

Firmware for ESP8266

Windows: NodeMCU Flasher

esptool.py

Documentation and source code

Instalation

pip install esptool

Example how to use it

python c:\Python34\Scripts\esptool.py --port COM7 erase_flash

python c:\Python34\Scripts\esptool.py --port COM7 write_flash -fm dio 0x000000 esp8266-20170823-v1.9.2.bin