I had proposed using a Micro:bit to control a programmable current sink to implement an VI curve tracer for the November Project14 DIY Test Instrumentation competition. Unfortunately, I had some personal issues that prevented me from being able to enter the competition. To my surprise, I received one of the Micro:bit packages from Element14 while I was away. Since I received the Micro:bit package, I thought that I would implement my design and post it here even though the competition is closed. I also need to complete a roadtest, so it may take me a couple of weeks before I can complete this project.
Block diagram of the project:
|1||Waveshare 160x128 LCD Display|
|1||MCP4725 I2C DAC Module|
|1||2N2222A NPN Transistor|
|Various Resistors and Capacitors|
The Waveshare LCD module with the Micro:bit attached.
The challenges that I see with this project will be mainly in generating the code. I'm new to the Micro:bit ecosystem so I'm not sure how much effort it will take to interface the I2C DAC and the SPI LCD Display. If this were an Arduino (or equivalent - I use a lot of ESP8266s) it would be straightforward because of all the available libraries. Waveshare provides code for running the LCD with the Microsoft MakeCode IDE but then I might have to "bit bang" the I2C so I'll probably use a different development environment.