The WCH QingKe CH32V003 is a $10c USD (< 1RMB) 32-bit 48Mhz RISCV micro controller (MCU) chip with 2KB SRAM and 16KB Flash. It comes in various pin packages including TSSOP20 (CH32V003F4P6) and smaller ones with less pins.
Official repo: https://github.com/openwch/ch32v003
You will need a programmer (the WCH-LinkE) to program it in most cases, or use an Arduino or ESP32 as an external programmer
- https://github.com/Community-PIO-CH32V/platform-ch32v - For programming ch32v using PlatformIO plugin on VSCodium/VSCode
- https://github.com/cnlohr/ch32fun - minimal stack for the ch32 and ch5xx WCH RISC-V Microcontrollers
- https://github.com/openwch/arduino_core_ch32 - Arduino core for the CH32 series
- https://github.com/limingjie/CH32V003-ST7789-Driver - ST7789 TFT color display driver. Timer interrupts might have issues while this one is active
- https://github.com/cnlohr/rv003usb - CH32V003 RISC-V Pure Software USB Controller, enables USB HID as well as bootloader for flashing code without a programmer
- https://www.youtube.com/watch?v=vplR-9WMz4E - Curious Scientist's CH32V tutorial playlist
- https://curiousscientist.tech/blog/ch32v003f4p6-interrupts - Tutorial on interrupts (using the WCH SDK, none-os). Same blog has many other tutorials on CH32
- https://pallavaggarwal.in/2023/10/01/ch32v003-low-cost-mcu-programming/ - Tutorial series on CH32V003 programming
- https://cw2.github.io/ch32v003/ - contains list of devboards
- https://github.com/wagiminator/Development-Boards/tree/main/CH32V003F4P6_DevBoard - wagiminator has made a large amount of devboards for CH32* devices
- https://www.elecrow.com/uiapduino-pro-micro-ch32v003-v1dot4.html - UIAPDuino Pro Micro, enables Arduino IDE development without programmer using extra wiring and rv003usb
- https://github.com/cnlohr/lolra - Transmit 900MHz LoRa frames surprisingly far without a radio (And other radio shenanigans using ADCs, PWMs and I2S/SPI busses) including sending other RF data using CH32V203
- https://www.hackster.io/news/the-ch32-just-another-10-microcontroller-a4e5f894ba76 - 90% accurate voice digit recognition using Machine Learning
- https://www.hackster.io/jithinbp/ch32v003-blinky-wedding-card-fc8f60 - Low cost wedding invites with a cheap RISC-V microcontroller that has LED POV display, RGB, IR receiver, Li-Ion and charger via USB-C
- https://github.com/wagiminator/CH32V003-GameConsole includes schematics and 4 simple games (Arkanoid, Tris/Tetris, Invader and Lander) using i2c OLED. uses ADC input and calibration to reduce button pins
- https://hackaday.io/project/205032-ch32v003-mini-game-console/details (Snake, Pong, Jump Bird, Dino Run)
- https://www.uiap.jp/uiapduino/app/tinych32pad/lite/v0dot1 - a $5 game pad being developed using the UIAPDuino devboard