Ultimate GPS track values very erratic
Moderators: adafruit_support_bill, adafruit
Forum rules
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
- just_croaker
- Posts: 1
- Joined: Mon Aug 02, 2021 9:46 pm
Ultimate GPS track values very erratic
I'm kind of new to a lot of this, but I'm an old IT guy and wanted to play a bit. I hooked up an Ultimate GPS Breakout to a Pi 4. It's connected with the USB to TTL Serial cable you recommend in your tutorial. I found some Python code and everything seemed to be working fine, but the code was only outputting latitude and longitude. I modified the code to output track data, and the values I'm seeing vary widely. I let it run for an hour, nothing changed. I attached an external active antenna, no change. I took it outside, no change. The values I'm seeing are valid values for compass heading, but swing plus or minus 60 degrees or more. Any clues??
- adafruit_support_bill
- Posts: 88037
- Joined: Sat Feb 07, 2009 10:11 am
Re: Ultimate GPS track values very erratic
GPS does not measure heading directly. It calculates it from the recent history of changes in location. Since standard GPS resolution is on the order of meters, and noise in the system can result in random small changes in location, heading values for stationary or slowly moving units will be erratic.
Forum rules
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/