Pybricks for build hat? In python on pi?

[gregorianrants]

Is there any interest in making a Pybricks for the buildhat?

What about just doing it in python on the raspberry pi?

I have read in other places that there are issues with the rate sensors can be read. There is a new command that allows changing the rate data is output at.

Using selrate(10) with the motors causes data to be output every 10ms

Not sure how it works with other sensors as I don’t have any. I just use gpio sensors.

I have implemented my own attempt at this in python you can find it here
https://github.com/gregorianrants/buildhat-alternative

It only does speed control so far. I haven’t looked at position control. I have played about with stall detection and had success but it hasn’t been pushed to the repo yet, as the code need polish.

I have previously mentioned doing this in another question, but the previous version was in nodejs and was not a standalone library.

The current version is fully in python it loads the firmware its self and can be installed in other projects.

To see it in action you can have a look at this project.
https://github.com/gregorianrants/composed-robot

[laurensvalk]

Thanks for your note. See #812 for some previous discussion.

It would be quite doable to port the Pybricks motors and sensor drivers to the Raspberry Pi Build Hat. However, for some reason loading other firmware seems to require a signing key that we do not have. See also RaspberryPiFoundation/python-build-hat#135

Doing it in Python and interfacing with the existing Build Hat firmware isn't going to give a very good experience, since it would have all the same problems and limitations as the current implementation.

[gregorianrants]

Lets hope they do that one day, would be great to see.

[AndyA]

Whoop! https://www.raspberrypi.com/news/build-hat-firmware-now-fully-open-source/

[laurensvalk]

See also #812

[joubarc]

Considering the Build Hat seems to host a RP2040 which is micropython-capable, and that power come form a dedicated plug on the hat itself... I was also wondering (assuming PyBricks ever gets ported to it), if it could work autonomously - that is, not plugged on a Pi Board at all. Of course you'd need to be able to communicate with it (I doubt the Build Hat itself has bluetooth) somehow, but maybe it would be possible to do that while connected; and once done, unplug it and have it run autonomously...
In any case, even with a cheap Pi underneath, the fact that it's a not-too-expensive solution without batteries required can be very interesting for event where you need your model to run continuously (couch GBC cough). I'm already using the Build Hat Power supply to feed a Technic Hub anyway.

[dlech]

This is certainly possible. Perhaps the simplest solution would be to use an FTDI UART chip that also has GPIOs. This would provide a connection to the serial port for uploading firmware/user programs and a GPIO is needed for reset.

Also, FYI, we do have a working build of Pybricks for the Build HAT now. The I/O port driver isn't implemented yet, so it doesn't do much, but it is a start.