Background
The client, a defense company whose name is not published, is developing a system in which a main computer, a motion sensor (IMU) and motor controllers must talk to each other quickly and reliably. ProtoMakers developed the control board that connects them. Further details about the system are confidential.
The challenge
Three high-speed communication channels running in parallel, each at 2 Mbaud. At that rate, any delay in the code or any reflection on the cable shows up as corrupted messages.
What we built
- Processor: an STM32H562 running at 250 MHz, with external PSRAM.
- Communication: three full RS422 channels, each with a separate transmitter and receiver, and all traffic on DMA, so the processor is free for other work.
- Power: a 22–36 V input, e-fuse protection with current measurement on the power output, and a dedicated 3.3 V supply.
- Debugging: diagnosing communication corruption caused by a transmit line split to two connectors with no termination. The problem was in the cabling, not in the code.
The result
A board that moves data between all system components at full rate, with full documentation of the interfaces. Because the same engineer wrote the communication code and understood the physics of the line, the cabling fault was found quickly instead of being chased in the code.
