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# 1.17 MCAN FD Interrupt

This example shows how to use the MCAN module to transmit and receive CAN FD messages in Interrupt mode.

## Description

This application transmits and receives CAN FD messages on the CAN bus. To run this application, two evaluation boards of same type are required. These boards acts as different nodes on the CAN bus. Same application is programmed onto both the boards. Boards are connected to PC via UART. While running the application, user can send and receive CAN FD messages between the boards using UART console applications running on the PC.

### MCAN Message RAM Configuration

Allocate MCAN Message RAM configuration in contiguous non-cacheable buffer in the application. For example, uint8_t CACHE_ALIGN mcan0MessageRAM[MCAN0_MESSAGE_RAM_CONFIG_SIZE] attribute((section(“.region_sram”)));

## Downloading and Building the Application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps/mcan/mcan_fd_operation_interrupt_timestamp.

To build the application, refer to the following table and open the project using its IDE.

Project Name | Description
--- | ---
sam_a7d65_curiosity.X | MPLABX project for SAMA7D65 Curiosity Board
sam_a7d65_curiosity_pro.X | MPLABX project for SAMA7D65 Curiosity Pro Board

## Setting Up AT91Bootstrap Loader

To load the application binary onto the target device, we need to use at91bootstrap loader. Refer to the at91bootstrap loader documentation for details on how to configure, build and run bootstrap loader project and use it to bootstrap the application binaries.

## Setting Up the Hardware

The following table shows the target hardware for the application projects.

Project Name | Description
--- | ---
sam_a7d65_curiosity.X | SAMA7D65 Curiosity Board
sam_a7d65_curiosity_pro.X | SAMA7D65 Curiosity Pro Board

### Setting Up SAMA7D65 Curiosity Board

Setting up the board:

- Connect SAMA7D65 Curiosity Board to another SAMA7D65 Curiosity Board as per the pin connections shown below

  SAMA7D65 Curiosity Board - 1 | SAMA7D65 Curiosity Board - 2
  --- | ---
  PIN 1, J28 (CAN1) | PIN 1, J28 (CAN1)
  PIN 2, J28 (CAN1) | PIN 2, J28 (CAN1)
  PIN 3, J28 (CAN1) | PIN 3, J28 (CAN1)

- Connect the USBA port J3 on the board to the computer using a Type-C USB cable (to power the board)
- Connect the UART Debug port (J35) on the board to the computer using a FTDI-USB cable
- Close Jumper J32 (CAN1)

### Setting Up SAMA7D65 Curiosity Pro Board

Setting up the board:

- Connect SAMA7D65 Curiosity Board to another SAMA7D65 Curiosity Pro Board as per the pin connections shown below

  SAMA7D65 Curiosity Pro Board - 1 | SAMA7D65 Curiosity Pro Board - 2
  --- | ---
  PIN 1, J72 (CAN1) | PIN 1, J72 (CAN1)
  PIN 2, J72 (CAN1) | PIN 2, J72 (CAN1)
  PIN 3, J72 (CAN1) | PIN 3, J72 (CAN1)

- Connect the USBA port J1 on the board to the computer using a Type-C USB cable (to power the board)
- Connect the UART Debug port (J63) on the board to the computer using a FTDI-USB cable
- Close Jumper J81 (CAN1)

## Running the Application

1. Build the application using its IDE.
2. Open the Terminal application (Ex.: Tera term) on the computer for each board.
3. Connect to the J-link Virtual COM port of both the boards and configure the serial settings as follows:
   - Baud: 115200
   - Data: 8 Bits
   - Parity: None
   - Stop: 1 Bit
   - Flow Control: None
4. In the console associated with board 1, press ‘0’ to transmit a CAN FD message.
5. Transmitted message description and status will be displayed in the console window of board 1.
6. Received message will be displayed in the console window of board 2.
7. Follow the sequence below to send and receive different messages:
   - Press ‘1’ on board 1
   - Press ‘2’ on board 1
   - Press ‘3’ on board 1
   - Press ‘4’ on board 1
   - Press ‘0’ on board 2
   - Press ‘1’ on board 2
   - Press ‘2’ on board 2
   - Press ‘3’ on board 2
   - Press ‘4’ on board 2
8. If the steps are executed in this sequence, the final output in the consoles will be as below:

Rev: C