Friday, June 14, 2024

Feather of the Day: Adafruit Feather RP2040 CAN Bus Feather with MCP2515 CAN Controller #RP2040 #Adafruit #Feather

The Adafruit Feather ecosystem is so rich with hardware diversity, we wanted to share them, one each day. Today is the Adafruit RP2040 CAN Bus Feather with MCP2515 CAN Controller – STEMMA QT!

If you’d like quickly get started with CAN bus interfacing, with no soldering required, our Adafruit RP2040 CAN Bus Feather comes ready-to-rock with a microcontroller, CAN chipset, and terminal blocks for instant gratification. The controller used is the MCP25625 (aka an MCP2515 with built-in transceiver), an extremely popular and well-supported chipset that has drivers in Arduino and CircuitPython and only requires an SPI port and two pins for chip-select and IRQ. Use it to send and receive messages in either standard or extended format at up to 1 Mbps.

Messages are sent at about 1 Mbps rate – you set the frequency for the bus and then all ‘joiners’ must match it, and have an address before the packet so that each node can listen in to messages just for it. New nodes can be attached easily because they just need to connect to the two data lines anywhere in the shared net. Each CAN device sends messages whenever it wants, and thanks to some clever data encoding, can detect if there’s a message collision and retransmit later.

We’ve added a few nice extras to this Feather to make it useful in many common CAN scenarios:

  • 5V charge-pump voltage generator, so even though you are running 3.3V on a Feather board, it will generate a nice clean 5V as required by the internal transceiver.
  • 3.5mm soldered terminal block quick access to the High and Low data lines as well as a ground pin, without any soldering.
  • 120-ohm termination resistor on board, you can remove the termination easily by cutting the jumper marked TERM on the top of the board.
  • CAN control CS, Reset, Int, standby pins connected internally so you can use any FeatherWing without pin conflicts.

At the Feather’s heart is an RP2040 chip, clocked at 133 MHz and at 3.3V logic, the same one used in the Raspberry Pi Pico. This chip has a whopping 8 MB of onboard QSPI FLASH and 264K of RAM!  There’s even room left over for a STEMMA QT connector for plug-and-play of I2C devices.

Use

The Adafruit RP2040 CAN Bus Feather Guide provides all the details and use examples.

Projects:

Would you like to see this Feather in action? Check out the projects below:

In stock! You can buy the Adafruit RP2040 CAN Bus Feather with MCP2515 CAN Controller in the Adafruit shop.

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