Sailor Hat for Raspberry Pi is a Raspberry Pi power management and CAN bus controller board for marine and automotive use. The main features are:
- Power management for 2.7V supercapacitors that provide so-called last gasp energy for shutting down the device in a controlled fashion after the system power is cut. The amount of time the supercap can provide power depends on the SBC power consumption and the supercap capacitance, but 20F supercapacitors can power a Raspberry Pi 4 for 15--20 seconds.
- Peak power management: The same supercapacitor circuitry is able to provide peak current for power-hungry devices such as the Raspberry Pi 4B+, allowing those devices to be powered using current-limited subcircuits such as the NMEA2000 bus power wires.
- Protection circuitry: The board is protected against noisy 12V voltages commonly present on marine vessels or vehicles.
- Two CAN bus controllers, allowing for different bus configurations, such as two separate NMEA2000 buses, an NMEA2000 and an J1939 engine bus, or in automotive applications, two separate vehicle CAN buses.
- A battery-powered real-time clock circuit, allowing for the device to keep time even in absence of GPS or internet connection.
- ATtiny841 microcontroller that controls the board communicates with the computer using I2C and has pins and memory available for custom functionality.
This repository contains the KiCad hardware design files for Sailor Hat. There are two other related repositories: firmware and daemon.
A rendering of Rev.G circuit board:
The PCB layout of Rev.G board:
