CAN Bus IO board

GalDotan · October 26, 2024, 1:04pm

Is there a Can bus to io board available on the market? Something with GPIO and those kind of outputs and inputs

truher · October 26, 2024, 1:48pm

this sort of thing does exist, for example this item

can be thought of as an Arduino shield with canbus and a few I/O ports. the Arduino code is simple and open source

ptmotorsport/IObox-emulator-haltech/blob/patch-1/emulator-v2.ino

#include <mcp_can.h>
#include <SPI.h>

long unsigned int rxId;           // storage for can data
unsigned char len = 0;            // storage for can data
unsigned char rxBuf[8];           // storage for can data

#define CAN0_INT 2                // Set INT to pin 2
MCP_CAN CAN0(10);                 // set CS pin to 10r

const int DPO1 = 3;
const int DPO2 = 4;
const int DPO3 = 5;
const int DPO4 = 6;




int scaledvalue1 = 0;             // storage for 12 bit analog value
int scaledvalue2 = 0;             // storage for 12 bit analog value

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so you could certainly adapt it to the FRC CAN standard. i think this would be a cool project!

NatsirtD · October 27, 2024, 4:17am

I’ve been working on something for use outside of FRC that does this. Using an ESP32 Devkit C V4, a TJA 1050 transceiver, and a 1/3 voltage divider. I can successfully send messages between two boards:

Wiring:

Code: Github
Real-life photos:

GalDotan · October 27, 2024, 10:41am

That’s exactly what I’m thinking about. I think we will buy the materials and try doing something like this ourselves, Do you know if this CAN board will work to communicate between the Rio and Arduino?

This is the board that I am searching about
https://a.aliexpress.com/_oCstrXt

NatsirtD · October 27, 2024, 5:58pm

If using a board without a can controller built in (like an Arduino), you need a combined controller-tranciever board like an MCP2515 board.

person4268 · October 28, 2024, 4:22pm

A lot of boards like that have a termination resistor soldered on. You might have to remove it with a soldering iron (once you figure out which one it is by looking at the traces), if you want to integrate it into a regular robot can network.

Also yeah, you’ll need an MCP2515 or similar if you’re using an actual Arduino.