New PCB ready to send for fabrication - a mini CO2 sensor with Sharp Memory LCD, precise RTC and UV/visible sensor too. The PCB is about as small as my KiCad skills and hands can make it - about 40mm wide. "Shoulder buttons" to navigate the UI. Supercapacitor to keep the RTC time for about a week with no power plus LiPo charge management. The heart of it is the #CH32V203 MCU - 144Mhz 32-bit #RISCV with 64K FLASH and 20K SRAM (about 46 cents each).

Over the weekend I worked on the Sharp LCD version of the Pocket CO2 project and things are starting to come together. This one uses the CH32V203 which has 64K FLASH and 20K SRAM. The nice thing about having a 128x128 LCD and an IMU is that the display orientation can follow the 4 possible device orientations.

#CH32V203
#scd40
#CO2

The #RISCV #CH32V203 version of my Pocket CO2 sensor is coming along. The schematic is nearly complete and I hope to order my first PCBs this weekend. Lots of sensors and soldering challenges. The parts so far:
- CH32V203F8P6 (64K FLASH / 20K SRAM, 144Mhz)
- SCD4x CO2 sensor
- LSM6DS3 6DOF IMU
- LTR-390 UV/Visible light sensor
- RV-3032-C7 low power RTC
- 3x high power white LEDs (flashlight)
- TP4057 battery charge controller
- 128x128 Sharp Memory LCD
- 2x push buttons
- 2x status LEDs

This morning's project - turn this frustrating solderless breadboard failure into a reliable soldered version on 2-sided tinned protoboard.

#CH32V203
#USB

New assignment for me today - memorize the #CH32V203 TSSOP20 pinout (I just got a set of chips from LCSC to experiment on).