[TangerineSDR] [EXTERNAL] Magnetometer/Grape Raspberry Pi Image

[Bill Engelke]

Hello Jonathan:

- I use the Adafruit Ultimate GPS Hat for Raspberry pi, about $37 on Amazon. It is accessed by simply reading port /dev/serial0
- to my knowledge, gpsd is not involved (unless it is embedded in firmware on the chip, which is not updateable as far as I can see)

My system is  down at the moment; it worked fine for 3 or 4 months running 24x7 - but then suddenly it failed and the R-Pi would no longer boot if the Adafruit GPS hat was on - saying "No USB interface detected" or something like that. (I have 2 hats: first, the Adafruit, and on top of that the TAPR magnetometer - this arrangement worked fine for months).  I am guessing that something electronic in the cheap board just failed - whadda ya want for $37 - so I ordered a new Adafruit board but have not had a chance to install it.

-73- Bill



-----Original Message-----
From: Jonathan <emuman100 at gmail.com> 
Sent: Sunday, October 31, 2021 8:01 PM
To: TangerineSDR Listserv <tangerinesdr at lists.tapr.org>; Unknown <hamsci at googlegroups.com>
Cc: Bill Engelke <bill.engelke at ua.edu>
Subject: [EXTERNAL] Magnetometer/Grape Raspberry Pi Image

Bill,

If I remember correctly, you used a GPS hat for the Raspberry Pi on the Magnetometer/Grape system. Is this true? If so, which one do you use?

The reason I ask is that there was a bug in gpsd that caused the GPS date to be erroneously reported as March of 2002 once October 23th
2021 has passed. This has been fixed and you are encouraged to update to gpsd version 3.23.1. To do so, do a git pull of the gpsd repository, then type "git checkout release-3.23.1", then "scons -c && scons && scons install".

Details about the bug can be found at:
https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.com%2Fgpsd%2Fgpsd%2F-%2Fissues%2F144&data=04%7C01%7Cbill.engelke%40ua.edu%7Cc6f3fc676b49415bfef408d99cd30a25%7C2a00728ef0d040b4a4e8ce433f3fbca7%7C0%7C0%7C637713252497565427%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=bf4noJ1F1zcyraoofXmbKhyAkvaGxfYZn4ojjrLIX9Q%3D&reserved=0 or LWN, El Reg, or CERT write ups.

As of this email, version 3.32.2 is the most current, but there is a bug that prevents using the GPIO PPS with another serial device than /dev/ttyAMA0. Most GPS hats use /dev/ttyAMA0, so you can do a git checkout and build/install of gpsd, but since I use /dev/ttyAMA0 for a serial console (I still believe in out-of-band access), I utilize
/dev/ttyUSB0 from a FT230 USB serial interface IC that my GPS serial port connects to, which then connects to the Pi USB port. In this configuration, version 3.23.2 of gpsd cannot use the /dev/ttyUSB0
/dev/pps0 runtime option and capture PPS asserts/clears from the pps_gpio driver. But, most GPS hats and users don't use this configuration very often, so you won't be affected. A fix for this issue will be pushed to the gpsd repository soon.

I owe a huge thanks to the primary maintainer of gpsd for working with me to get both issues resolved, as well as support for the Trimble RES SMT 360 timing receiver and Solaris 10 support.

Jonathan
KC3EEY