KiCad design for Raspberry Pi Hat. Provides power and switch on/off
for the board. A total of 1.2A is provided for use by the
RaspberryPi. Also some connectors for GPS, barometric sensor, and ADC
measurements. Provides 12V power for a remote video board which is
switched at the same time as the Raspberry Pi. Contains a MCP2515 CAN
Controller and MCP2551 CAN transceiver for access to CAN bus. The
transceiver is isolated from the rest of the board. Has a
connector that allows I2C
devices to be connected to the Raspberry Pi.
- Onboard ATmega328P
- 1.2A DC power for RaspberryPi provided by
- Video board power (12V) controlled by solid state relay G3VM-201FR
- Serial Connector for GPS with 5V power, routed to Raspberry Pi Uart1.
- 2 connectors with 4 pins each routed to adc pins on ATmega328P
- Qwiic Connector, routed to I2C1 on Raspberry Pi
- eeprom & power isolation as required by Raspberry Pi hat spec
- Onboard 3.3V power for the ATmega328P.
- SPI on ATmega328P routed to the Raspberry Pi SPI0 for communication
- MCP2515 CAN network device, controlled by Raspberry Pi on SPI1
- CAN is isolated to meet specs of NMEA 2000.
- Connector for external voltmeter, or see 13.
- Optional 12V voltage divider routed to ADC7 on the ATmega328P. This option is selected by a solder jumper.
There are 2 projects for the firmware. One is using C, the other Rust.
for the onboard ATmega328P using avr-gcc and avr-libc.
.
The Rust firmware is still experimental. There are a number of compiler bugs for the 8-bit AVR's yet.