I am using USB GPS receivers in single board computers like Odroid-xu4 and Raspberry Pi 3 with different operating system.
The following are the behaviours observed:
1. Odroid-XU4 with globsat bu-353 S4 GPS Receiver:
In this board,I installed Dietpi OS v6.7 and kernel version is 3.10.106+. GPS receiver had a good fix and displayed all data in a right way. On the following day, it displayed a wrong data showing co-ordinates of sea. After a while it shows correct data. Generally, it often shows correct as well as wrong data. Baud rate of the GPS is 4800 baud
2. Odroid-XU4 with U-Blox AG USB GPS Receiver:
In this board too I installed Dietpi OS v6.7 and kernel version is 3.10.106+. Baud rate of GPS is 4800 baud. Here GPS showed correct data. After few days it displayed an error as follows:
gpsd: gpsd:ERROR: PPS ioctl(TIOCMIWAIT) failed: 25 Inappropriate ioctl for device
The full detail is as follows:
service gpsd status gpsd.service - GPS (Global Positioning System) Daemon Loaded: loaded (/lib/systemd/system/gpsd.service; static) Active: active (running) since Thu 2018-07-19 10:49:38 IST; 5min ago Main PID: 2124 (gpsd) CGroup: /system.slice/gpsd.service └─2124 /usr/sbin/gpsd -N -n -G -b /dev/ttyACM0 Jul 19 10:49:38 Busplay2 systemd: Started GPS (Global Positioning System) Daemon. Jul 19 10:49:39 Busplay2 gpsd: gpsd:ERROR: PPS ioctl(TIOCMIWAIT) failed: 25 Inappropriate ioctl for device
What is PPS ioctl? What’s the issue here?
3. Raspberry Pi3 with globsat bu-353 S4 GPS Receiver:
In this pi board, I installed Raspbian OS and kernel version is 4.14.50-V7+. I am using it for the three days with the GPS receiver. It displays data correctly. I neither getting any error (such as pps ioctl) nor any wrong data.Baud rate is 4800 baud.
4. Odroid-XU4 with globsat bu-353 S4 GPS receiver:
Here I installed Ubuntu mate OS and kernel version is 4.14.0-83. Similar to the above case (raspberry pi 3), I am not getting any error or any wrong data. Everything is going fine.Baud rate is 4800 baud.
So my question is why is GPS showing such a behaviour in Dietpi OS?