the current uart1 overlay allows for the remapping of the pinsabelectronicsuk wrote:I want to be able to remap the hardware UART TX and RX
Would that overlay also work if it is on a HAT card and the HAT is put on top a Raspberry Pi 2?PhilE wrote:I'll put together an overlay that disables Bluetooth and UART1 and maps UART0/ttyAMA0 to GPIOs 14 & 15.
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sudo systemctl disable hciuart
Thank you for doing this, I havent used the overlays before and need to learn how they workPhilE wrote:I'll put together an overlay that disables Bluetooth and UART1 and maps UART0/ttyAMA0 to GPIOs 14 & 15.
Setting the core_freq sounds like a better solution. All Pi's have enough speed for light and sound control.PhilE wrote: Would it not be better to peg the core_freq at 250Mhz to avoid any speed fluctuation and use uart1?
Hi, Thanks for trying to fix this. I installed your overlay file and added the dtoverlay command to my config.txt file. However, when I reboot the boot sequence hangs with the following output:PhilE wrote:
I've pushed the new overlay (pi3-disable-bt) to the rpi-4.1.y source tree. You can download a pre-built version here.
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A start job is running for LSB: control configuration of serial ports (3min 34s / no limit)
Clean install from Noobs 1.8 (Downloaded today).PhilE wrote:It works for me. Which distribution are you using, and how did you get to this point - clean install, upgrade etc.?
This seems to have fixed the login problems via uart but when i tried runningPhilE wrote:Try using console=serial1 in cmdline.txt. It will get mapped back to ttyAMA0. I'm working on a firmware update that will restore the original behaviour when the overlay is used, but for now this one weird trick is necessary.
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sudo systemctl disable hciuart
This is great newsPhilE wrote:The mini UART (ttyS0) does not support parity. I will create an overlay that uses ttyS0 for the BT modem, which may work for low baud rates and data volumes. Using it will also require the systemd script (/lib/systemd/system/hciuart.service) to be edited.
To use, add this to your config.txt:Switch Pi3 Bluetooth function to use the mini-UART (ttyS0) and restore
UART0/ttyAMA0 over GPIOs 14 & 15. Note that this may reduce the maximum
usable baudrate.
It is also necessary to edit /lib/systemd/system/hciuart.server and
replace ttyAMA0 with ttyS0.
If cmdline.txt uses the alias serial0 to refer to the user-accessable port
then the firmware will replace with the appropriate port whether or not
this overlay is used.
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dtoverlay=pi3-miniuart-bt
I have made a copy of the overlay and included the link in a blog post on (link removed) for all the steps I used to setup the serial console with the overlay. Once the overlay is included in the full release, I will update the post and remove the file.PhilE wrote:I've pushed the overlay (pi3-miniuart-bt) to the source trees. It will appear in the next release, or you can download prebuilt one here.
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