evm-esp32

A virtual machine for ESP32, allowing dynamic program updates.

Based on my implementation of CHIP-8, where the gaming related instructions are removed, and instead instructions for IO pin controlling are added.

The following instructions that are related to games (drawing, etc.) are removed:

• 00E0
• DXYN
• EX9E
• EXA1
• FX0A
• FX18
• FX29

The following instructions that are related to IO control are added:

• E0A0 - sleep for second register's value milliseconds
• EXA1 - sets the pin mode X to the pin (value in first register)
• E0A2 - does analogRead to the first register and stores the result in the second register
• E0A3 - does analogWrite to the first register using the value from the second register

Registers are changed from 8 bit to 16 bit.

In order to reload a program, use the 0000 instruction to halt the VM and restart.

Tested on ESP32 Arduino (WROOM32).

Prerequisites:

• Install analogWrite polyfill

References:

• http://en.wikipedia.org/wiki/CHIP-8
• https://github.com/bor0/chip-8
• https://ieeexplore.ieee.org/document/9828788
• https://hackaday.com/2022/02/27/esp32-virtual-machine-lets-you-change-programs-on-the-fly/

Boro Sitnikovski