Mike1369
Posts: 2
Joined: Sat May 28, 2016 4:36 pm

GPS Hat to talk to the serial port

Sat May 28, 2016 9:05 pm

I'm new at this, just registered today and I have a question related to this subject. I have a RPI 2 and after the latest Jessie update/upgrade /dev/ttyAMA0 went away and my GPS Hat no longer works. I have tried all kinds of combinations of turning off serial in rasp-config, updating /boot/config.txt enable_uart=1, which looks to me to be the same as turning on serial in raspi-config and I cannot get data to/from the ttyAMA0. I really have tried to find the answer on my own but I'm at a dead end.
What combination of settings will allow the GPS Hat to talk to the serial port ttyAMA0 again?
Thanks,
Mike

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Milliways
Posts: 580
Joined: Fri Apr 25, 2014 12:18 am
Location: Sydney, Australia

Re: Where is /dev/serial0

Sun May 29, 2016 4:40 am

Mike1369 wrote:I'm new at this, just registered today and I have a question related to this subject. I have a RPI 2 and after the latest Jessie update/upgrade /dev/ttyAMA0 went away and my GPS Hat no longer works. I have tried all kinds of combinations of turning off serial in rasp-config, updating /boot/config.txt enable_uart=1, which looks to me to be the same as turning on serial in raspi-config and I cannot get data to/from the ttyAMA0. I really have tried to find the answer on my own but I'm at a dead end.
What combination of settings will allow the GPS Hat to talk to the serial port ttyAMA0 again?
Thanks,
Mike
If you are using a Pi2 that has NOTHING to do with this Topic which is about Pi3.

Mike1369
Posts: 2
Joined: Sat May 28, 2016 4:36 pm

Re: GPS Hat to talk to the serial port

Sun May 29, 2016 1:24 pm

Very helpful, thanks.

DirkS
Posts: 10445
Joined: Tue Jun 19, 2012 9:46 pm
Location: Essex, UK

Re: GPS Hat to talk to the serial port

Sun May 29, 2016 2:13 pm

Mike1369 wrote:Very helpful, thanks.
It is, because now you have your own topic and you may even get a relevant response...

Does /dev/ttyAMA0 exist?

Please give more details of the hardware you're using (what GPS hat?).
What software do you use?
And details of any relevant settings.

quinness
Posts: 17
Joined: Thu Mar 10, 2016 12:02 pm

Re: GPS Hat to talk to the serial port

Sun May 29, 2016 2:35 pm

May it be that the GPS is on /dev/ttyUSB0?
Raspian Jessie 2016-02-26 _-=* If there are choices, why complain? *=-_
openSUSE LEAP 42.1 (3 pcs) _-=* Uppland, Sweden *=-_

PhilE
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 3463
Joined: Mon Sep 29, 2014 1:07 pm
Location: Cambridge

Re: GPS Hat to talk to the serial port

Sun May 29, 2016 3:00 pm

The USB bus isn't available to HATs, so the answer is probably no.

beta-tester
Posts: 1391
Joined: Fri Jan 04, 2013 1:57 pm
Location: de_DE

Re: GPS Hat to talk to the serial port

Sun May 29, 2016 5:12 pm

Mike1369 wrote:...
I have a RPI 2 and after the latest Jessie update/upgrade /dev/ttyAMA0 went away and my GPS Hat no longer works.
...
What combination of settings will allow the GPS Hat to talk to the serial port ttyAMA0 again?
hi mike,
was the OS jessie befor updating/upgrading, or was it wheezy?
and what is not working?
(are you able to connect and get useful data by using minicom?)

Code: Select all

minicom -b 9600 -o -D /dev/ttyAMA0
btw: i made a script to turn a GPS module (possibply compatible to your GPS HAT, if it is that https://www.adafruit.com/products/2324)
and a RPi into a Stratum one time server. possibly you can take a look to the content to find out, what you need.

PS: in the script i turn the GPS module to use a high boud rate and a high update frequency - it turned out, that those settings let my GPS module reset after 7-10 days - no idea why, possibly an buffer overflow issue, but with the default baus rate (9600) and the default update interval (1Hz) it runs stable. so better to do not use that part, where i do the switch.

here is the link: https://github.com/beta-tester/RPi-GPS-PPS-StratumOne
{ I only give negative feedback }
RPi B (256MB), B (512MB), B+, ZeroW; 2B; 3B, 3B+; 4B (4GB)

smokeysteve
Posts: 1
Joined: Sat Sep 07, 2013 11:17 pm

Re: GPS Hat to talk to the serial port

Fri Jun 03, 2016 10:46 am

Here's some better information on the recent changes to the serial port: viewtopic.php?f=66&t=148515

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