ESP32 MicroPython Home Air Quality Station

Software

• Python 3 (i.e. Miniconda/Anaconda). I highly recommend creating new dedicated virtual environment for your project with following libraries:
  • esptool - pip install esptool
  • adafruit-ampy - pip install adafruit-ampy
• USB to UART drivers:
  • CH340 - download
  • PL2303 - download
  • CP210X - download
• Latest ESP32 firmware - download

Hardware

• ESP32 (i.e. DOIT ESP32 DevKit v1)
• Plantower PMS7003 air quality sensor
• USB-UART PL2303
• USB cable
• Jumping wires
• Breadboard

Optionally

• Temperature/humidity/pressure sensor (i.e. DS18B20, DHT11, BME280)
• RTC
• SSD1303 OLED display

Preparing the board

Check COM PORT

Let's plug ESP32 into computer and check whether everything was installed correctly and board is visible by our machine. Running following command in the terminal ls /dev/tty*USB* should return ESP32 COM PORT (i.e. /dev/ttyUSB0 on Linux or /dev/tty.SLAB_USBtoUART on MacOS). If nothing shows up make sure you have installed software correctly.

Erase flash

To make sure that everything is up to date we should erase flash on ESP32 running following command:

python -m esptool --chip esp32 erase_flash

It should automatically find COM PORT.

Write latest firmware

When our flash was erased we can write latest firware to our board using command. Double check port and path to the downloaded firmware file.

python -m esptool --chip esp32 --port <port> write_flash -z 0x1000 <path/to/esp32/firmware.bin>

Connect to the REPL

screen /dev/ttyUSB0 115200

Check files on board

ampy --port /dev/ttyUSB0 ls

Put a file on board

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

Run file

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

How to install micropython libraries on esp32

• Connect to the REPL.
• Connect to the Internet.
• Install desired package. For further details please visit official micropython-lib repository.

import upip
upip.install('micropython-urllib.urequest')