If you like to experiment there is a magnetometer BMM150 in M5Core Gray, Fire and M5GO. Also the M5StickC ENV Hat contains the same BMM150. But I guess you already knew that.
thank you for the test application. I've added my test (using a finger) in the issues section. I think I have a stylus somewhere and when I find it I'll give it another go.
Wow! I was looking for a pocket calculator for my twelve year old. I had an m5stack faces laying around, flashed with RunCPM, but unusable for me because of the tiny font it uses.
I followed up on this project with another that's a real calculator. It was more work than I had anticipated; that might explain why there are so few examples: https://github.com/vkichline/FullCalculator-Arduino
The README includes pictures this time.