CAN Bus Development

Items to use:

1. STM32F103x boards
2. MCP2551 CAN Transceivers

About CAN

CAN (Controlled Area Network) Protocol is a way of communication between different devices, but under certain rules. These rules must be followed when a message is transmitted over the CAN bus.

Rules for Standard CAN frame

• Here, Identifier is the ID of the transmitting Device
• RTR (Remote Transmission Request) Specifies if the data is Remote frame or Data frame
• IDE specifies if we are using Standard ID or Extended ID
• r is the Reserved bit
• DLC specifies the data length in Bytes
• Data Field is where we can send the data, which should be upto 8 bytes
• Checksum and DEL are the CRC data and it’s Delimiter
• ACK and DEL is the acknowledgment bit and it’s Delimiter

Setting Up IOC

• Here the BAUD RATE is set to 500000 bps. You can try different different combinations for Prescalar and Time Quanta to achieve this.
• The Operating Mode is NORMAL Mode
• Pins PA11 and PA12 are set as CAN_RX and CAN_TX from here

Hardware Connections

https://lastminuteengineers.com/mcp2515-can-module-arduino-tutorial/

Change 500kb/s time prescaler from 18 to 36 in stm32 and it should work with arduino uno