unleashed-firmware/wiki/hw-1.0.md
2020-08-02 08:17:52 +03:00

868 B

Hardware version 1.0

device schematic

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 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)