CAN Board

Features:

• 6 CAN lines
• RP2040 microcontroller
• 16MB flash
• Many Interfaces
  • USB-C
  • UART
  • SPI
  • GPIO
• SWD debugging

This board has 6 independent CAN lines driven by 6 MCP251863T-E/9PX CAN controllers. Each CAN controller is interfaced with the central microcontroller through an internal SPI bus along with 2 interrupt pins for general purpose and RX interrupts. There is also a STBY pin for the CAN transceiver that is connected to the XSTBY pin on the CAN controller.

RP2040 Pinout

GPIO	Function
0	UART TX
1	UART RX
2	SPI0 SCK
3	SPI0 TX
4	SPI0 RX
5	SPI0 CS 1
6	SPI0 CS 2
7	SPI0 CS 3
8	SPI0 CS 4
9	SPI0 CS 5
10	SPI0 CS 6
11	SPI1 TX
12	SPI1 RX
13	SPI1 CS
14	SPI1 SCK
15	GPIO pin 1
16	CAN6 RX INT
17	CAN6 INT
18	CAN5 RX INT
19	CAN5 INT
20	CAN4 RX INT
21	CAN4 INT
22	CAN3 RX INT
23	CAN3 INT
24	CAN2 RX INT
25	CAN2 INT
26	GPIO pin 2
27	GPIO pin 3
28	CAN1 RX INT
29	CAN1 INT

Notes:

• SPI0 is the internal SPI bus which connects to the CAN controllers with SPI0 CS X being the chip select for CAN controller X.
• SPI1 is the SPI bus exposed over the SPI connector.
• GPIO 15 (GPIO pin 1) is attached to a mosfet and LED as an indicator and therefore should have pull down enabled if being used as an input.
• GPIO 26 & 27 (GPIO pin 26 & 27) can be used an analog inputs.
• CANX INT is a general purpose interrupt pin for CAN controller X that will trigger when any interrupt in the CAN controller is triggered. This pin is inverted (active LOW).
• CANX RX INT is configurable to trigger when CAN controller X's RX interrupt is triggered. As an interrupt, this pin is inverted (active LOW).

Project Structure

• CAD: The kiCAD project (PCB/schematics)
  • Components: Imported components each in their own folder
  • Fab: All the fabrication files including BOM, gerber, and component placement
• code: Firmware for the microcontroller in a pretty standard C project structure
  • include: Header files
  • src: C/C++ files
• images: All the images