I can't receive anything other than non-printing characters from the uBlox GPS that comes with a new ErleBrain3. I would like a very simple command-line query of the GPS coordinates.
There are several instances on this forum of similar effects in an ErleBrain2, e.g. http://forum.erlerobotics.com/t/solved-trying-to-get-some-sensible-data-from-the-gps/722/12 but none of those solutions has worked. Is there anything else I should try, that is specific to an ErleBrain3?
THE PROBLEM:
Immediately after re-flashing the CF card, and logging in via ssh, I get the following output
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Thu Oct 13 20:22:47 2016 from 10.0.0.2
erle@erle-brain-3 ~ $ ls
APM Documents gtk-tests ros2_ws spider.launch spider_ws
erle@erle-brain-3 ~ $ sudo stty -F /dev/ttyS0
speed 9600 baud; line = 0;
-brkint -imaxbel
erle@erle-brain-3 ~ $ sudo python
Python 2.7.9 (default, Mar 8 2015, 00:52:26)
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import serial
>>> ser = serial.Serial('/dev/ttyS0',9600,timeout=1)
>>> print ser.readline()
%±%¥51e¬@
µ%11M1
!ñ%1
E¥
>>> print ser.readline()
±±Ü5¡¥Þ±1%@
¡Ã¥¥Æ±1%¬t!%¡G¡µ¡Ä¡Ö5
A¡%%w¡%±±%q¬;
±Ä!Äå%!%*
FAILED SOLUTIONS:
* apm.service is not installed, let alone running (when it was running on a previous flash, sudo stty -F /dev/ttyS0 was indeed returning random baud rates, consistent with a previous thread).
* I have tried different baud rates, but still get similar non-printing characters.
* I have tried forcing core_freq=250 in /boot/config.txt and rebooting to solve the known issue of the system clock in RPi3s ( https://frillip.com/raspberry-pi-3-uart-baud-rate-workaround/ )
* I have reflashed the CF card with Erle-Brain3-frambuesa-09-12-2016.img
Am I being stupid? I'm good with linux, but new to serial ports. Any ideas would be very gratefully received. Thank you!