Integrating STM32 MCU for Automotive CAN Bus Data Logging in Custom Dashboards

[Mekaeln]

Hello ST Community,

I am working on an automotive telemetry and dashboard integration project using an STM32 series microcontroller (STM32F4/H7) to process real-time CAN bus telemetry data from vehicle OBD-II interfaces.

We are testing sensor readouts and data logging configurations for custom vehicle diagnostic builds over at John Autos.

I have a few technical questions regarding CAN transceiver power states and interrupt priority handling:

1. What is the recommended DMA configuration to handle high-frequency CAN messages without dropping frames during burst transmissions?

2. Are there specific low-power mode considerations when keeping the MCU connected to the vehicle's constant 12V battery line via a step-down regulator?

Any insights or HAL driver examples would be greatly appreciated!

[Karl Yamashita]

You should create a transmit queue so that if the STM32 Tx buffers are full, you don’t drop you CAN message and it waits until a TX buffer is empty so you can send what’s in your tx queue.

As for power, you should select an LDO that has a low quiescent current draw. Is the STM32going to sleep when there is no data activity? Depending on what other circuitry is involved, drawing less than 5-10ma is what you should shoot for.