3 ms·
The Raspberry Pi 5 has also done something similar: the CPU no longer controls the GPIO directly, but through a RP1 southbridge. Maybe that's what you're thinki
by ThatPlayer 1y ago
The Raspberry Pi 5 has also done something similar: the CPU no longer controls the GPIO directly, but through a RP1 southbridge. Maybe that's what you're thinking of? Don't see any mention of latency on Jeff's review on it, and I doubt the Radxa X4 is popular enough for any big in-depth review like that.
It looks like the RP2040 on the X4 is connected via USB. The RP2040's bootloader mode that enables flashing emulates a mass storage device over USB to transfer firmware, so it would be confusing to not connect it via USB.
- teamonkey 1y agoTo clarify, the issue with the X4 is that it essentially is no different than having a Pi Pico attached via USB. This means that your x86 program doesn’t directly control the GPIOs, it must communicate with the RP2040 over USB serial. The RP2040 must be flashed with a firmware that knows how to handle these serial commands. It works, but it’s an extra step and timing may be an issue. On the other hand, a Raspberry Pi Linux program can toggle GPIO pins natively simply by using the official libraries. I mentioned the RP1 in another comment.