Preparing the ESP32 for MicroPython

About 2 years ago, I wrote a small library to create menus on an ESP8266/32 utilising the SSD1306 OLED Display and MicroPython.

MicroPython is a stripped down variant of Python, basically made for IoT devices. A very well known example of such device-series is the Arduino Family or ESPs.

Installing the USB-Serial driver

There are two common chips on ESPs: CP210x or CH340x. Those chips can be found close to the USB-Connector on the ESP-Board.

As shown on the picture above my board uses the CH340C USB to UART bridge. Drivers can be found on different pages and highly depend on the platform and chip. I got mine from this page https://sparks.gogo.co.nz/ch340.html, more specifically the linked GitHub Repository. A high number of Stars and signed drivers / a Brew repository are a good indication for a valid source (but no guarantee !)

Getting the right Firmware

After successfully installing the driver I needed to find the right firmware for my specific ESP board model. To run MicroPython an a device, it needs the firmware to be installed on the flash first. MicroPython offers a huge selection of firmware-versions on their Download Page. If your specific version is not shown on the filtered list, a very close version should be enough for it to work.

I personally used a lolin32 v.1.0 for my initial testings and the basic Espressif ESP32 binary worked just fine.

Flashing the Firmware on the ESP

There are a few different ways to flash a new firmware on an ESP. My personal favourite is the Espressif esptool.py which can be downloaded directly or installed via pip.

The command shown in the screenshot above deletes all the existing flash contents of the ESP. The –port argument describes the physical connection to the ESP, in my case it was called /dev/tty.usbserial-14220.

The tool also shows the version of my ESP-board: ESP32-D0WDQ6, and the installed features.

The next command will upload the earlier downloaded firmware to the devices flash storage.

This command looks very similar to the command earlier, the difference is the action we process on the device write_flash with the argument -z followed by the start address 0x1000 and the path to the binary.

We can now test the setup board by establishing a serial connection via a terminal emulator like picocom to the device.

We can now run MicroPython code on our ESP device. Next step will be the actual planning of the Project :3

This article is a bit less deep than intended. Reason for this is the wide variety of combinations that can be used. If you have any in-depth questions don’t hesitate to contact me ! :3