The individual assignments for this week are:
- write an application that interfaces a user with an input &/or output device that you made
One of the biggest challenges this week was deciding whether to use MicroPython or Arduino. Last week I designed and printed a board that has three Xiao ESP32S3’s on it, which are connected via I2C. I was planning to only use these three boards, and have one of them serve as the “leader”, which would collect step response data from its seven sensors, AND be responsible for collecting the sensor data from the others, AND host a webserver that could talk to my phone, AND control a LCD screen.
I originally leaned towards having the leader board’s code be written in MicroPython, while the other boards run the step response script that I used in a previous week.
Anthony told me that to get best results, I should use Arduino with the step response sensors since Arduino is a lot faster and more consistent. Moreover, even though Neil used MicroPython in his web app example, there are sufficient libraries in Arduino to do everything that MicroPython can do.
This is quite a complex solution, and would probably require all of the boards to figure out synchronization with each other.
I have since realized that there is a much simpler solution: I move the “leader” functionality off of one of these three boards, and have these three boards act exclusively as sensors and sensor output boards. I then program another board that is connected to these three boards over the same I2C connection, and have that one be responsible for collecting the sensor data from the three sensor microcontrollers, host a webserver, and control a LCD screen. Moreover, this board’s software can be written in MicroPython, since it isn’t as sensitive to fluctuations at runtime. Additionally, this modularizes the code, as I can program the sensor boards once, and once I am confident that they are behaving correctly, I won’t need to conftinue to modify their code anymore and run the risk of messing it up.
Thus, this week I will be focused on writing the code for the “leader” board, which will be responsible for hosting a WiFi network and web app, receiving sensor data, and controlling a LCD screen. Since this week’s assignment is focused on writing a UI, I’ll be focused on the first responsibility.
Also, in the process of deciding, I found a few guides online on how to make quite advanced projects on an ESP32, including hosting a React app, which I am surprised fits on an ESP32’s flash. I would like to try them out at some point, maybe in the future when I have more time. But for now, I’ll just list them here.
I used Neil’s blink example as starter code for this project.
The important things are: to modify the HTML and JS in the server response so that I have the UI I want, have the device keep some sort of state to represent the current sensor data, and handle creating and accepting websockets with the client device (phone or computer) over WiFi.
If I have time, I also want to figure out how to have it store data in the flash, e.g. a leaderboard. A quick search shows that I want to be storing this data in EEPROM.
I found a website that I think could be very useful as a guide in implementing websockets.