Analogue Inputs Messed Up

shmed · Post by **shmed** » Fri Mar 14, 2014 9:28 am

I finally got round to installing my RCP, and have only a few requirements until the CAN adapter is sorted:

1. Get the RCP to turn on my GoPro when it detects voltage on an input
2. Read a pulsed RPM input from my ECU

So when trying to achieve requirement 1, I wired a simple 12v switched circuit into the car, and connected the switched live to pin 14 on the RCP (Analogue IN 1). Looked in RaceAnalyzer, and no voltage was detected.

I sanity checked all my wiring, and found that I definitely had 12V at the RCP input.

Then I tried GPIO 1. Nothing. Just read 1 on sensor monitor irrespective of the switch position.

So, I decided to try analog2 (Pin 13). All of a sudden, I see voltage on analog 1 (and nothing on analog 2).

I haven't delved any further into this problem as yet to see where the mapping goes awry, but I will do next time I have half hour.

Additionally, I have wired my RPM output from the ECU to pin 20, but am not sure what advanced settings I should set on this input? I currently get no reading on that input whatsoever. Assuming it is a pulsed digital input, what settings should I consider?

I do have a basic scope, but don't totally know what I'm doing with it....

shmed · Post by **shmed** » Thu Mar 20, 2014 9:00 pm

I connected to my ecu and have identified that the tach out from the ecu is 2 pulses per rev, which is nice. But neither my rev counter, or the rcp are reading any revs. Could it be that the output from the ecu is under driven.

GTIspirit · Post by **GTIspirit** » Fri Mar 21, 2014 1:08 am

shmed wrote:I connected to my ecu and have identified that the tach out from the ecu is 2 pulses per rev, which is nice. But neither my rev counter, or the rcp are reading any revs. Could it be that the output from the ecu is under driven.

How does the signal look? Is it a 5V square wave? Or is it a signal from the coil? The RCPro needs a nice sharp ~5V digital square wave signal for speed signals.

Post by **brentp** » Fri Mar 21, 2014 7:08 am

Hi - Using the sensor monitor feature in RCP, can you enable all of the analog channels with a sample rate (1Hz is ok) ; write the config to RCP, and then jumper the 5v VREF output from RCP back into to the analog inputs, on by one to test them? See if you can observe any changes on the sensor monitor screen. Let us know what you find out if you can do this test.

Also, yes - the RPM signal needs a sharp square wave. We also have the CoilX module which is designed to tap into the coil primary trigger wire and provide the proper signal. Test it with your scope to see what kind of signal you can get!

Post by **brentp** » Mon Apr 07, 2014 10:28 pm

shmed,

Any luck with this? Let us know what the latest is.