unleashed-firmware/wiki/hw/Hardware-version-F1B1C0.0.md

Device schematic (pdf)

Errata

• NAND reset IC drive reset net by push-pull output may cause MCU fault and disable internal MCU reset feature.
• System going to boot-loop state when reset by reset circuit
• No series resistors on external gpio for protecting MCU
• Wrong value LED series resistor
• Wrong footprint for CMOS transistors
• Wrong value IR TX series resistor
• No need capacitor on IR RX
• Wrong value IR RX pullup resistor
• 125 kHz RFID + iButton wrong schematic
• It seems bad to place main VCC on external GPIO pins. Overcurrent can damage main regulator and cause device broken. User can apply wrong voltage on this pin.

New RFID + iButton schematic

after many experiments we found good schematic solution for work with RFID and auxiliary follow iButton level (for non-TTL protocol like Cyphral)