4-Letter 14-Segment indicator toy

Hardware

PyCharm
MicroPython plugin
Google Blockly is used to edit and run display programs online.
- The blocks are converted to JavaScript code to be run in the browser window
- The blocks are converted to MicroPython code to be run on MCU side
GitHub pages hosts the web part
EMQ Free Public MQTT Broker helps to exchange data between web- and hardware- part
MicroPython is run on the ESP32 MCU and handles both the display and MQTT connection
HT16K33 Python driver
micropython-mqtt

Solder the Grove connector (shipped with the module) to M5 Stamp-C3U Port A
Connect the display module to the MCU module
Connect the MCU module to your computer with USB cable. A COM port should appear
Flash latest MicroPython to the MCU module. JS ESPTool is a handy tool for it. Note that .bin file should be flashed at address 0x0000
Create a (free) account at a public MQTT broker (ex https://www.hivemq.com/, https://www.emqx.io/)
Create your own cloud MQTT broker
Create an MQTT user. NB! Create a strong password and keep it well, otherwise your WLAN may be hacked!
Write your own SECRETS.py file based on the template secrets_template.py. There should be your specific Wi-Fi SSID, Wi-Fi password, and MQTT lo.
Upload newly created SECRETS.py to the MCU module filesystem. You may use either PyCharm with MicroPython plugin, Thonny, or mpremote
Upload MicroPython code to the MCU board. The tools are above
Reboot the board
Open elmot.xyz/esp32-blockly-display/
Click gear icon and enter your MQTT parameters, same as in MicroPython part
If everything is done correctly, The board connects to the MQTT broker
- Wi-Fi sign on the web page turns to be dark green
- On-Board LED turns green after several seconds

Blocks are stored to browser's local storage.