Raspberry Pi 3 breaks the serial port

I'm told it works with UART0. This is bare metal - ie without whatever Linux/Device Tree does on top of it. I did a brief test with booting NOOBS/Raspbian and got some messages out - I don't know what to expect and only had the TX pin wired so couldn't interact with it, but the messages looked OK.

Theo

Theo,

It may well produce messages out, but what I need (and what worked on the RPi-1 and RPi-2) is to access data coming in on that port from a

9600 baud serial GPS device. Sending isn't critical, receiving it is.

On the RPi-2 I could make a couple of changes:

- removing ttyAMA0 string(s) from /boot/cmdline.txt

- commenting out lines in /etc/inittab (not required with Raspbian Jessie)

and check access with:

minicom -b 9600 -o -D /dev/ttyAMA0 or: cgps -s

but this appears broken on the RasPi-3. Not amused, as there are dozens of devices relying on this!

--
Cheers, 
David 
Web: http://www.satsignal.eu

Are you saying the DT and firmware fixes in that blog post don't work?

On 05/03/2016 09:30, mm0fmf wrote: []

[]

So far:

- I have removed ttyAMAO references from /boot/cmdline.txt

- I have added, to /boot/config.txt

dtoverlay=pps-gpio,gpiopin=18 dtoverlay=pi3-disable-bt

- I have updated the firmware /only/ with rpi-update.

Thanks to your post, I see that there is a pi3-disable-bt-overlay.dtb file available, which I have now downloaded, but I don't know where to place that file, or what other edits I may need to make to enable it. Is that the firmware fix you mean?

Thanks!

--
Cheers, 
David 
Web: http://www.satsignal.eu

find / -name \*.dtb is probably a good place to start.

Googling for "using overlays with jessie pi" gives, amongst others,

Thanks. I actually used the "locate" command to find where .dtb files should be placed. Copying the .dtb file there, and edit /boot/config.txt, all is now well. Many thanks for your help!

Now to tackle the failure of gpsd to auto-start. Good looking help on this group about that as well.

--
Cheers, 
David GM8ARV 
Web: http://www.satsignal.eu