GPS in place of VSS

[Kristian]

Hi, I've searched the forum, but couldn't find anything relatively recent on GPS use. I see that there is a vehicle speed setting for throttle off fuel cut, but the car does not have a VSS sensor in the dash (91 manual 1.6). I'd like to add the option of disabling this function if the car is under a certain speed, say 20mph. One option would be to swap out the speedo from one from an auto and hope the electron pipes are plumbed between the dash and the computer. the other is to swap the whole speedo or cluster for a NB and use an electronic speed sender in the gear box, but i thought the whole $20 GPS might be the easier way to go. I see that you can configure a GPS in tuner studio, but figured that must be for a GPS plugged into the computer running TS?
Can I plug a TTL/UART GPS directly into a PNP 91 Miata Hellen Rev B board, which plugs to use (I presume RX/TX J4?), and which settings do I need to change in TS to allow the board to use GPS as a vehicle speed input, I've set up the GPS baud rate to 38400 with a refresh rate of 100ms.

Thanks
Kris

[nmstec]

From personal experience, GPS for VSS is terrible if you need it for mission critical things. Including deaccel, TCM & etc.

If you're using it for speedo, its good enough.
The issue lay in cities, or in terrible signal areas (Including tunnels).

My recommendation, if you're going this route, is to use a CAN based GPS module, as there are plenty made for cars, and they are way easier to work with when using LUA on rusefi ecus.

https://www.ecumaster.com/products/gps-to-can/

[mck1117]

To answer your real question, instead of answering a different question as Mark has done:

We don't currently support connecting a serial NMEA GPS to the ECU, no. While technically possible, we don't really want to parse NMEA on the ECU itself, since it's some extra work for the CPU (it's busy enough running your engine!). Some of the code is there, but it certainly isn't hooked up, and there's no plan to do so.

[Kristian]

Thanks