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Dtynin

•Created by Dtynin on 12/16/2024 in #🪲-firmware-and-baremetal

Fixing CAN Bus Overload Issues in Multi-Node Sensor Systems Using AVR128DA48 and MCP2515

Hey guys, I previously worked on an automated irrigation system where different sensors (moisture, temperature) spread across large farmland communicate with a central controller over the CAN Bus. Each sensor node is equipped with an AVR128DA48 microcontroller and an MCP2515 CAN controller to relay data about soil conditions to the controller for real-time decision-making. I’ve set up the CAN Bus network and successfully initialized the CAN controller on each sensor node. The sensor data is being collected properly, and I've verified that the SPI communication between the AVR128DA48 and the MCP2515 is working correctly. However, I’m running into an issue when attempting to synchronize the sensor data broadcasts. The issue occurs during message reception on the central controller. While I’m able to send data from individual sensors, the central node fails to synchronize the data streams. The can_recv() function sometimes receives data, but other times it throws an -EBUSY (Bus Busy) error, suggesting the bus is overloaded or not handling multiple messages well. this is my code:

int ret = can_recv(can_dev, &rx_frame, K_MSEC(100));
if (ret == -EBUSY) {
    LOG_ERR("CAN bus busy, could not receive message");
} else if (ret == 0) {
    LOG_INF("Received CAN message with ID: 0x%x", rx_frame.id);
}

int ret = can_recv(can_dev, &rx_frame, K_MSEC(100));
if (ret == -EBUSY) {
    LOG_ERR("CAN bus busy, could not receive message");
} else if (ret == 0) {
    LOG_INF("Received CAN message with ID: 0x%x", rx_frame.id);
}

Error

[00:00:03.005] <ERR> CAN bus busy, could not receive message

[00:00:03.005] <ERR> CAN bus busy, could not receive message

I expected that the can_recv() function should smoothly capture messages from all the sensor nodes, ensuring each node’s data arrives at the controller in real-time without interruption.

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