low cost 10C on ESP32-S3

[arhtur]

I was at a Maker Faire and saw the M5Stack Cardputer and thought it would be the perfect development platform for a RPN calculator, hence the 10LC. It cost $30 and on Microsoft Word, I made an overlay that I printed with adhesive backed paper. Using the Arduino IDE, I wrote code to mimic the 10C. It accepts a micro SD card to store program steps and registers (I use a Sandisk Ultra 16GB SDHC card - slower cards seem to have R/W issues with the hardware).

There are some limitations, such as its small size (about 3.25 inches x 2.25 inches), engineering notation has not been implemented, and the tangent function accuracy is limited when close to 90 degrees.

But some features include selectable font size, selectable font color, selectable audible beep for key press, and it's fast - approx. 100,000 loop iterations in 10 seconds. Also, there are 99 program steps and 10 memory registers. It can be updated via USB-C on a Windows PC. I've put binary files and overlay .pdf files on Github under 10LC. The standalone unflashed M5Stack Cardputer can be bought at the M5Stack website or Digikey. I may have some pre-flashed or pre-assembled units (for more than $30) on Tindie or Etsy. This might be the perfect DIY project to build for a middle school or early high school student that you want to introduce RPN to, or someone wanting a low cost RPN calculator to take anywhere.