Pseudonymous electronics designer "Maker and IoT Ideas" has built a development board based on the Microchip ATtiny1616 microcontroller and boasting CAN bus support — as a jumping-off point for automotive experimentation.
"A short while ago, I started looking at alternatives to the ATmega328P (the chip used in the standard Arduino UNO). That experiment turned out quite well, with two of the three chips turning out to be useful, the ATtiny1616 and the ATmega4808. [Now I am] adding dedicated CAN bus support to the 1616 and 8408. I am planning to add some gadgets to my car, and would like to have it controlled by a CAN bus interface, and, just maybe, interfacing with the CAN bus on the car as well — at least in the future."
The plan, then: the development of a pair of microcontroller boards with integrated CAN bus support, starting with one built on the low-cost Microchip ATtiny1616 microcontroller. To this, Maker and IoT Ideas added an Microchip MCP2515 CAN bus controller, the ATtiny1616 lacking any such functionality in itself, and an NXP TJA1050 CAN bus transceiver — both of which dwarf the tiny ATtiny1616.
"These chips, while old, are still easy to get hold of," the maker explains, "and I have quite a few of them lying around from previous projects. It did thus seem to be a good starting point. The fact that their libraries also works perfectly with the ATtiny1616 and ATmega4808 also went a long way towards selecting them for the project."
Using an earlier QFN-chip breakout as a jumping-off point, Maker and IoT Ideas designed a new board which includes both the microcontroller and the CAN bus components — bringing the CAN signals out to a screw header at the rear of the board, to ease connection and disconnection during experimentation. Missing from the design, though, is any form of USB connectivity; instead, the maker programs the microcontroller — using Garry Fowler's MCP CAN Library — through a homemade UPDI programmer.
The full project write-up is available on the Maker and IoT Ideas website, along with schematics for the board.