Project Log - November 13, 2025

Prototypes arrived from JLCPCB and initial assembly/testing is underway.

Assembly completed: Pcb is now populated with components. Hand-soldering went smoothly with stencil for paste application.

Issues found and fixed:

• Case screws too short - need M2.5 x 8mm instead of 6mm (my bad)
• PN7150 NFC chip: missing trace between pins 2-3, fixed with small solder bridge
• CC1101 balun: same issue, solder bridge applied
• STM32 BOOT0 control: added thin copper wire from ESP32 GPIO to BOOT0 pin for DFU mode switching (cleaner than original design)
• Display flex cable: tore during assembly (user error), repaired with careful resoldering

Components tested and working:

• Both MCUs (ESP32-S3 and STM32G431) boot and communicate via UART
• TFT display (2.4" ST7789V3) - full color, touch, graphics
• All 6 buttons (D-pad + A/B) with proper debouncing
• RGB LED
• USB switching between ESP32/STM32 (hardware mux confirmed working)
• GPIO header
• IR transmitter/receiver
• I2C EEPROM (AT24C256)
• SD card reader
• LiPo charging circuit
• PN7150 NFC (works but code not finished for it)
• Battery fuel gauge

Still testing:

• LoRa module (868MHz) - SPI communication next
• CC1101 Sub-GHz - RF testing pending
• Full firmware integration

Next steps:

• Complete RF testing (LoRa range test, CC1101 frequency sweep {pure hell} )
• Finalize case design (adjust screw boss height) --> i just brocke and sandet the resin case 🔥
• Begin firmware development for LoRa mesh and Sub-GHz protocols
• Prepare for Kickstarter video shoot

Overall: Hardware validation looking good. Minor fixes needed for production revision but nothing blocking the February launch timeline.