This ECU box is sold on Aliexpress for ca 30.- USD and include the connector. On my M12 design I was stuck with expensive M12 connectors, so this offers a cheaper way to get a waterproof, shielded box.
The motherboard and daughteboards below are designed so it contains PSU, Ethernet, 2 x CAN, main MCU amd 1, 2 or 4 daughter cards to form a complete ECU.
This is just a classic mock-up to see if I have physical space for what I want to do. But, I have some conserns:
- Ethernet is good, but 100Mbps Ethernet might nor work over that connector so it might be degraded to 10Mbps.
- PSU – firstly a fully isolated PSU is included on 24V itself, but I struggle to support 10A.
- I was thinking a simple, linear regulator for 5V, but I just did that and realized what a misstake it was. The board used 250mA and 250mA on 24V is 6W – the regulator overheat without cooling. So in short I need a 2A 24 to 5V regulator as well.
- The daughter boards restrict PSU size.
- The commector has no key options.
- Ethernet + CAN is a bit of a waste – you don’t need both.
It is an interesting experiment, but I am not there yet. To move on I am considering doing a version of the M12 design with normal connectors and ditch ECU requirements just so I can focus on SW development and dev-kits for BSA. I need to split out the PSU design and get it to work + I would like to do a Ethernet design on H573 because this comes with Ethernet in 64 pin package-I am still a big fan of H723 and G4 MCU’s, but H503 costing 2.- USD is a very promissing option to lower cost even in smaller volumes.
As for IO
- Ethernet
- CAN
- PWM out – the boards above is actually 4 x PWM @5A each.
- Analogue In.
- Digital In/Out
- Power Servo channels
This is what I have with full galvanic isolation – the challenge has been more the connector and boxing side of the project + the obvious time in between projects that pay my bills 🙂
As for actual ECU design – a professional ECU will need ASIL-D/SIL3 qualification and I am preparing for that, but that is a big job. So for now I ignore this and just experiment on my way.