Re: GPS speed logging app, anyone got any suggestions?
Posted: Tue Oct 07, 2025 12:26 pm
Thanks Goodman.
I've actually moved on a bit since then. I wanted to monitor the fuel pressure while the car is driving but as the fuel pressure varies with manifold/plenum pressure it's not just as simple as taking the gauge pressure on at the regulator, the manifold pressure (vacuum) also has to be taken into account.
What I did was read values from a pressure sensor on the fuel regulator and a MAP sensor reading plumbed into the plenum and combined them to check for constant differential. I did this via a microcontroller.
Having done that I decided I'd like to have the logs timestamped so I could compare against logs from the ECU, problem is the microcontroller didn't have a real time clock. I then realised that the easiest way to add a RTC was to link a GPS receiver to the microcontroller, this is not only real time but accurate to milliseconds (or micro seconds if I use a more sophisticated GPS) and I also get GPS coordinate, road-speed, altitude and several other things which I may or may not need.
Mostly pointless but it was a bit of fun to do and I wanted it for other purposes too. I now have quite a useful data logging device which I can plug in other sensors to if required.
I've actually moved on a bit since then. I wanted to monitor the fuel pressure while the car is driving but as the fuel pressure varies with manifold/plenum pressure it's not just as simple as taking the gauge pressure on at the regulator, the manifold pressure (vacuum) also has to be taken into account.
What I did was read values from a pressure sensor on the fuel regulator and a MAP sensor reading plumbed into the plenum and combined them to check for constant differential. I did this via a microcontroller.
Having done that I decided I'd like to have the logs timestamped so I could compare against logs from the ECU, problem is the microcontroller didn't have a real time clock. I then realised that the easiest way to add a RTC was to link a GPS receiver to the microcontroller, this is not only real time but accurate to milliseconds (or micro seconds if I use a more sophisticated GPS) and I also get GPS coordinate, road-speed, altitude and several other things which I may or may not need.
Mostly pointless but it was a bit of fun to do and I wanted it for other purposes too. I now have quite a useful data logging device which I can plug in other sensors to if required.