General discussion • Re: What is the default GPIO UART actually capable of?

Various UART Device Tree overlay definitions can be found in the kernel GitHub. The two most useful overlays are disable-bt and miniuart-bt.

disable-bt disables the Bluetooth device and makes the first PL011 (UART0) the primary UART. You must also disable the system service that initialises the modem, so it does not connect to the UART, using sudo systemctl disable hciuart.

miniuart-bt switches the Bluetooth function to use the mini UART, and makes the first PL011 (UART0) the primary UART. Note that this may reduce the maximum usable baud rate (see mini UART limitations below). You must also set the VPU core clock to a fixed frequency using either force_turbo=1 or core_freq=250.

That was it! Thank you!

Now I just need to figure out what I want to do with that. If bluetooth wasn't involved, the choice would be a lot easier. Something tells me I want to keep that how it was (though I'm not sure *why* BT can't use the mini one), which would mean that I need to redo the hat to use a different UART. But at least it gets me going for now.

As trejan said, check the official documentation to get the Primary UART on the GPIO pins https://www.raspberrypi.com/documentati ... ring-uarts

And I see that the Pi 5 just doesn't have this problem. No mini-UART at all there, so everything has the full functionality regardless. Something to look forward to next time I upgrade.

For terminal apps have a look at minicom and PuTTY.

Is there something better about those? I can use a CLI, but I kinda like a GUI for that, which CuteCom has.

Statistics: Posted by AaronD — Tue May 07, 2024 12:07 am

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