So I have decided to add WiFi to my display. It will not compromise display part, but will make it a more versatile tool for my sensor experiments. Also it adds another dimension to the project - it can not only display sensor data, but also whatever data pulled from the net!

I have chosen ESP32C3 as the main micro-controller because of two reasons - it's low power and it's risc-v based - I wandered how good risc-v support is in the standard Arduino tool chain. Also ESP32C3 has in build USB-to-serial peripheral saving the need to design in USB-to-serial converter chip.

Unfortunately, 2450 batteries had to go as they couldn't support high current spikes during WiFi communication. Thus AA batteries had to come in. I hesitated a bit between AA and AAA, but opted for AA to have more juice, meaning more communication and more display updates.

I have chosen to use bare ESP32 chip and add printed 2.4GHz antenna to the PCB mainly to use this as an opportunity to learn something, also I didn't want to change the size of the PCB a lot and module is a bit bulky. I still have to go to RF lab to perform antenna measurements, I have just ordered bare PCBs with U.fl connector added for this specific task.