MSgpio.com read only forums (Jan.15,2018)

I decided to figure out what was wrong with my speed sensor so I routed it into the MS3 instead of GPIO, but the various code I have used all has VSS offset limit of 255. I found a thread where you addressed this, but it is 4.133. I am downloading that code for the GPIO, but I'd think you would want that changed for all current stable and test code.


Andrew

Andrew,

I was also fighting VSS issues early on, thread here viewtopic.php?f=4&t=822 "4L60E VSS signal jumpy on roll-out".

I eventually got it working quite well, after experimenting with different resistor and capacitors in parallel. Getting a scope on it was key to see what I had to work with. The resistor knocked down my peak to peak voltage, and the capacitor smoothed out some small ripples that is coming from a 120VAC inverter that I use.

I too was thinking about using the MS3 VSS circuit, as it has a more advanced freq to digital circuit. But with a little experimenting, you can get MSShift to work good also.

As another data point, my first MS project was using uS to run a 1958 flat head Cushman scooter engine. I used a front wheel speed sensor off a 2001 Silverado pickup, which was looking at a custom made 60-1 cam wheel. The uS speed circuitry worked right out of the box, no tweaking. So I'm thinking you'll have good luck with the MS3 VSS.

Dave

I got the VSS working over can with the older firmware that allows offset to be greater than 255. The problem I see is that when comparing the VSS signals from GPIO CAN input to the MS3 VSS1 gauge, the GPIO is reading about half the speed! In the parking lot at my shop idling around I get up to 6-7 mph but the gpio only shows me at 3. How do I fix this?

I am using offset 336 and outpc size of 512


Andrew