PiMaster HAT: IoT Gateway for Raspberry Pi

PiMaster HAT: IoT Gateway for Raspberry Pi

This HAT acts as a gateway between the CAN bus network and a Raspberry Pi. In practice, the Omzlo PiMaster HAT runs the network management software for the NoCAN platform. If you want to design IoT applications for use at home or in the garden, pair this HAT with one or more Canzero nodes.

Check the following link if you would like to learn more about NoCAN.

PiMaster HAT Features

PiMaster HAT is based on an STM32F042 ARM Cortex M0+ microcontroller running at 48MHz. This microcontroller (MCU) communicates with the Raspberry Pi through the SPI protocol and additional GPIOs. The PiMaster HAT performs three main functions:

• Acts as a gateway for the NoCAN network (CAN bus).
• Controls and monitors the power supplied to the network (generally 12V or 24V).
• Supplies power to the Raspberry Pi from a 6V to 28V source.

NoCAN is a software application running on the Raspberry Pi to manage the network and also performs the following functions:

• Turns the NoCAN network on or off.
• Monitors voltage and current levels.
• Registers nodes and assigns each one a specific address.
• Registers channels as part of the publish-subscribe (pub/sub) protocol used in NoCAN.
• Reboots nodes by activating their bootloader.
• Uploads or downloads firmware (hex files) to/from each node.

If excessive current consumption is detected, usually when it exceeds 3A, a smart switch (MOSFET) acting as an integrated safety system will immediately cut off the network power supply. This smart switch is controlled by the MCU.

The PiMaster HAT works with any Raspberry Pi featuring a 40-pin header, including the Raspberry Pi Zero.

PiMaster HAT Technical Details

This HAT integrates the following components:

• Main MCU: STM32F042
• CAN bus IC interface (MCP2562)
• Step-down converter powering the Raspberry Pi (based on the TI TPS54202, supplying up to 2A)
• A MOSFET smart switch controlling power distribution to the network (Infineon BTS5030)
• Three LEDs:
  Red: HAT power status.
  Green: Network power status.
  Yellow: Power fault indicator.
• A pluggable 4-pin 3.5mm pitch connector providing network and power connection (VIN, GND, CAN_L, CAN_H).
• A 2.1mm DC power connector supplying 6V to 28V to the HAT.
• Debugging connectors.

The PiMaster HAT kit includes:

• 1x fully assembled PiMaster HAT board, with a pre-soldered 40-pin GPIO header (for connecting the HAT to the Raspberry Pi).
• 1x 4-pin male screw terminal block.
• 2x 11mm M2.5 spacers and 4x M2.5 screws
• 1x 120 ohm through-hole resistor (optional for transmission line termination)

Please note: to build a NoCAN network, one or more CANZERO nodes, a Raspberry Pi, a power supply, and some cables/wires are also required. These components must be purchased separately because they are NOT included in the PiMaster package.

PiMaster HAT Resources

If you would like to obtain additional information about PiMaster and NoCAN, PiMaster HAT schematics, and source code, you can consult the introduction to the NoCAN platform and/or this detailed installation tutorial.