marcelotournier / esp32-micropython

How to configure esp32 with micropython

ESP8266 Setup

I am using a macbook pro M2, but I assume the setup will be the same for other computers, by following the tutorial from https://docs.micropython.org/en/latest/esp32/tutorial/intro.html

1. Installing dependencies

Installing esptool:

pip install esptool

2. Erasing the factory firmware

To install micropython you must first erase the original factory firmware.

To do it, connect the ESP32 in the USB port, wait for the PWR LED to light and run in terminal:

esptool.py --port /dev/tty.usbserial-0001 erase_flash

In my Mac, the tty port was /dev/tty.usbserial-0001. To find the right tty port, you can run ls /dev | grep usb

In my case I was getting the error

A fatal error occurred: Failed to connect to Espressif device: Wrong boot mode detected (0x13)! The chip needs to be in download mode.
For troubleshooting steps visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html

I followed the guide from https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html and in my case I had to put the board in Download mode manually. So I looked at the extra instructions at https://docs.espressif.com/projects/esptool/en/latest/esp32/advanced-topics/boot-mode-selection.html#manual-bootloader.

In my case I had to keep the boot button in the board pressed while I re-ran the estool.py command above.

3. Downloading micropython firmware

I downloaded the most recent version from https://micropython.org/download/#esp32

4. Install firmware

Go to where you downloaded the firmware file and run:

esptool.py --chip esp32 --port /dev/tty.usbserial-0001 --baud 460800 write_flash -z 0x1000 esp32-20220618-v1.19.1.bin

5. Accessing the Micropython REPL

You must get it through the usb port using picocom. This command should exist in linux (based on what the docs said). For mac, install it with homebrew (https://brew.sh/)

brew install picocom

and then run in your port:

picocom /dev/tty.usbserial-0001 -b115200

Then... Bingo! You just hacked your first ESP32! :)

$ picocom /dev/tty.usbserial-0001 -b115200
picocom v3.1

port is        : /dev/tty.usbserial-0001
flowcontrol    : none
baudrate is    : 115200
parity is      : none
databits are   : 8
stopbits are   : 1
escape is      : C-a
local echo is  : no
noinit is      : no
noreset is     : no
hangup is      : no
nolock is      : no
send_cmd is    : sz -vv
receive_cmd is : rz -vv -E
imap is        : 
omap is        : 
emap is        : crcrlf,delbs,
logfile is     : none
initstring     : none
exit_after is  : not set
exit is        : no

Type [C-a] [C-h] to see available commands
Terminal ready
EK:?MicroPython v1.19.1 on 2022-06-18; ESP32 module with ESP32
Type "help()" for more information.
>>>

To exit the picocom connection to the REPL do Ctrl-a then Ctrl-x

6. Copying files to ESP32:

I am using ampy, from adafruit (https://github.com/scientifichackers/ampy):

# ref: https://boneskull.com/micropython-on-esp32-part-1/
pip install adafruit-ampy

To list files:

ampy -p /dev/tty.usbserial-0001 ls

To get file contents:

To put a file in ESP32 (DANGER - it overwrites):

7. Configuring network:

import network

# Checking which mode it is - access point or client mode:
sta_if = network.WLAN(network.STA_IF)
ap_if = network.WLAN(network.AP_IF)

# station interface?
sta_if.active()
# False

# access point interface?
ap_if.active()
# True

Connecting as AP interface:

SSID = "Micropython-ESP32"
PASS = "123123"
ap = network.WLAN(network.AP_IF)
ap.active(True)
ap.config(essid=SSID, password=PASS)

WebREPL

This is a nice way to interact with the ESP32. To setup, first install nodejs in your machine, then run in the micropython shell:

import webrepl_setup

and follow the instructions. The first option should be E to enable it. Set the password and then accept rebooting.