Install Latest MicroPython to M5Stack

M5Stack is an absolutely beautiful ESP32 based enclosure and development board. It has 320x240 TFT screen, three buttons, sd card slot, Grove I2C connector and can be powered with LiPo battery.

Download the Micropython Firmware

You could download the MicroPython firmware from the downloads page. But why bother when we have the commandline. First find the download link.

$ curl --silent http://micropython.org/download | grep "firmware/esp32" | gawk -F'<a +href="' -v RS='">' 'RT{print $2}'

http://micropython.org/resources/firmware/esp32-20180127-v1.9.3-240-ga275cb0f.bin
$ lynx -listonly -dump https://micropython.org/download | grep "firmware/esp32" | sed 's/.*http/http/'

http://micropython.org/resources/firmware/esp32-20180127-v1.9.3-240-ga275cb0f.bin

When download link is known, download the firmware.

$ wget http://micropython.org/resources/firmware/esp32-20180127-v1.9.3-240-ga275cb0f.bin

--2018-01-27 20:05:26--  http://micropython.org/resources/firmware/esp32-20180127-v1.9.3-240-ga275cb0f.bin
Resolving micropython.org... 176.58.119.26
Connecting to micropython.org|176.58.119.26|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 935888 (914K) [application/octet-stream]
Saving to: ‘esp32-20180127-v1.9.3-240-ga275cb0f.bin’

esp32-20180127-v1.9 100%[===================>] 913.95K   284KB/s    in 3.2s

2018-01-27 20:05:30 (284 KB/s) - ‘esp32-20180127-v1.9.3-240-ga275cb0f.bin’ saved [935888/935888]

Install the Tools

First make sure you have esptool installed. This is the commandline tool which will be used for flashing. Both Python 2 and Python 3 versions should be ok.

$ pip2 install esptool

Collecting esptool
  Downloading esptool-2.2.1.tar.gz (70kB)
    100% |████████████████████████████████| 71kB 94kB/s
Requirement already satisfied: pyserial>=2.5 in /usr/local/lib/python2.7/site-packages (from esptool)
Requirement already satisfied: pyaes in /usr/local/lib/python2.7/site-packages (from esptool)
Requirement already satisfied: ecdsa in /usr/local/lib/python2.7/site-packages (from esptool)
Building wheels for collected packages: esptool
  Running setup.py bdist_wheel for esptool ... done
  Stored in directory: /Users/hello/Library/Caches/pip/wheels/e8/63/0f/01c12901098b6be9d1e7e3e5bc50ef92f1f44a45534095aefa
Successfully built esptool
Installing collected packages: esptool
Successfully installed esptool-2.2.1

Erase the Flash

Connect the M5Stack to your computer with the provided USB cable. Make sure esptool can connect.

$ esptool.py --port /dev/cu.SLAB_USBtoUART --baud 115200 --after no_reset read_mac

esptool.py v2.1
Connecting........_
Detecting chip type... ESP32
Chip is ESP32D0WDQ6 (revision 0)
Uploading stub...
Running stub...
Stub running...
MAC: 30:ae:a4:04:f0:d4
Staying in bootloader.

If esptool connected successfully continue by erasing the flash. Erasing is not absolutely necessary, but usually a good idea to avoid random problems.

$ esptool.py --port /dev/cu.SLAB_USBtoUART  --baud 115200 --after no_reset erase_flash

esptool.py v2.1
Connecting......
Detecting chip type... ESP32
Chip is ESP32D0WDQ6 (revision 0)
Uploading stub...
Running stub...
Stub running...
Erasing flash (this may take a while)...
Chip erase completed successfully in 4.5s
Staying in bootloader.

Flash the new Firmware

The Micropython binary contains bootloader, partition table and the firmare itself concatenated in one file. You should flash this file at offset 0x1000. I use relatively low speed of 115200 for flashing. It takes bit longer but in my experience has less problems.

$ esptool.py --port /dev/cu.SLAB_USBtoUART --baud 115200 write_flash --flash_mode dio --flash_freq 80m --flash_size detect 0x1000 esp32-20180127-v1.9.3-240-ga275cb0f.bin

esptool.py v2.1
Connecting......
Detecting chip type... ESP32
Chip is ESP32D0WDQ6 (revision 0)
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Auto-detected Flash size: 4MB
Flash params set to 0x022f
Compressed 935888 bytes to 587152...
Wrote 935888 bytes (587152 compressed) at 0x00001000 in 51.9 seconds (effective 144.4 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting...

You should now have brand Micropython firmware running on your M5Stack.

Make Sure Everything Works

After flashing connect to the serial REPL to make sure everything is ok. Press enter couple of times to see the prompt.

$ screen /dev/cu.SLAB_USBtoUART 115200
>>>

Picocom is also popular alternative for serial communication. You can install it from Homebrew.

$ brew install picocom
$ picocom -b 115200 /dev/cu.SLAB_USBtoUART
>>>

If you do not get the prompt try removing and reattaching the usb cable. After getting the prompt you can use uos module the make sure you are running the latest version. With gc you can check available memory.

>>>
MicroPython v1.9.3-240-ga275cb0f on 2018-01-27; ESP32 module with ESP32
Type "help()" for more information.
>>> import gc
>>> gc.collect()
>>> gc.mem_free()
90208
>>> import uos
>>> uos.uname()
(sysname='esp32', nodename='esp32', release='1.9.3', version='v1.9.3-240-ga275cb0f on 2018-01-27', machine='ESP32 module with ESP32')
>>>

Where to Buy?

You can find M5Stack from both Banggood and AliExpress. BangGood links below are affiliate links. I have had success ordering from both.

Model $
AliExpress M5Stack Basic $35.00 €28.60
AliExpress M5Stack MPU9250 $41.00 €33.55
AliExpress M5Stack MPU9250 4MB $43.00 €35.20
BangGood M5Stack Basic $32.99 €26.90
BangGood M5Stack MPU9250 $42.35 €34.50

Posted in Electronics  ESP32  MicroPython  on 27 Jan 2018.