RPM Signal Porsche 944

L Cubed · Post by **L Cubed** » Wed Aug 20, 2014 3:04 am

So I have tested this using the frequency input mode (Hz) instead of the RPM mode and had the same results. The same phenomenon also happened on all 3 frequency inputs of the RCP which is why I thought it might be something related to the input being grounded on startup.

For the PWM loopback do you mean to trigger the GPIO as an input and plug the RPM signal into that port and see if it logs regularly?

Post by **brentp** » Wed Aug 20, 2014 9:29 pm

You will want to loop one of the "Pulse/Analog outputs" into one of the RPM channels and test that way.

See this connection diagram:
http://autosportlabs.net/RaceCapturePro ... onnections

Let us know what you find out!

L Cubed · Post by **L Cubed** » Wed Aug 20, 2014 11:21 pm

So I ran this test and had the same problem after cycling power to the RCP.

What I did was connect the Pulse Output 1 (FreqOut1) to Pulse Input 3 (Freq1), RPM was wired to Pulse Input 1. With the computer still plugged into the RCP I started the engine and had both RPM and Freq1 recording a singal. I captured a log (Pulse Check-RC_3). Then I unplugged my computer, and cycled power to the RCP by toggling a switch on the +12V line; while leaving the engine running.

After restarting the RCP I took a log (Pulse Check-RC_4). I then plugged my computer back in to double check the sensor monitor and saw 0 for both RPM and Freq1. After this I pulled a third log (Pulse Check-RC_5). I confirmed that both of these logs showed zeros for the RPM and Freq1 inputs.

The three logs are attached. It seems to be a startup or power cycle related problem since it occurred on both inputs this time.

Post by **brentp** » Fri Aug 22, 2014 9:04 pm

Hi,

we will work to reproduce it on our end.

So bottom line, if RCP is powered up and *then* you start the engine, it works? And if you power cycle RCP while the engine is running, it stops logging RPM?

L Cubed · Post by **L Cubed** » Fri Aug 22, 2014 11:25 pm

So I did another test using the loopback pulse signal only. I power on the RCP and then unplug->replug the wire coming from the pulse output so that I can see it reading a value in the sensor monitor. Unplug the computer, leaving the unit on with 12V power from the car and record a log. Leaving the computer disconnected I cycle the 12V power to the RCP and then record another log. Looking at the before log I record a 2000 Hz pulse (500 us period as configured). In the second log I only get 0. Both logs show output from the pulse output channel.

So bottom line: My RCP does not record (either in Race Analyzer Sensor Monitor or in a CSV log file) after power is cycled to the unit. Cycling power a second time does not restore pulse input recording. The only thing that restores pulse input recording is to unplug and then replug the signal wire into the unit the next time power is turned on.

On a side note, would be worth trying Version 2 firmware and software?

L Cubed · Post by **L Cubed** » Sun Aug 31, 2014 10:36 pm

Brent any update from your end?

I did some bench testing and tried re-flashing the 1.2.8 firmware and still have the issue. I am planning to incorporate a N.C. momentary switch to RPM signal so that I can manually interrupt the signal to get it to log so I can get RPM in my logs.

Post by **brentp** » Tue Sep 02, 2014 6:37 pm

Hi - we will have some more information in the next couple of days!

L Cubed · Post by **L Cubed** » Sat Sep 06, 2014 12:49 am

So Brent, I have a new update, I was checking on the internals and found that the capacitor at C68 was not completely connected. See the attached picture. Could this be contributing to the issues I am seeing with the frequency measurement? I tried the loopback test again and it wouldn't work this time...

Post by **brentp** » Sun Sep 07, 2014 6:44 pm

Hi,

Could you try switching the channel mode for the channels you are testing to "Frequency" instead of "RPM" and see if a reading shows up on the sensor monitor for the different conditions you're testing in?

Also, can you confirm which firmware version you are running? Are you testing the V2 firmware / app or are you still on 1.2.8?

The mis-soldered capacitor is unrelated to this issue. It is a capactior attached to the gyro sensor. It looks like an assembly defect slipped past our testing. If you can solder it, that would be good, or we can fix it for you.

L Cubed · Post by **L Cubed** » Sun Sep 07, 2014 8:49 pm

Hi Brent,

I am using "Frequency" mode for the pulse input for the loopback test. I just redid the bench-top loopback test for all three pulse inputs and it worked after I unplugged and replugged it back in.

So the pulse input ports are working, though I still have the original issue of needing to interrupt the signal after power-up for the RCP to read the signal.

I re-flashed firmware version 1.2.8 because I didn't want to swap to the version 2 beta while still having this issue unless it may help.

The yaw sensor is working fine for now so I'll check continuity to see if it is a cold joint or not.

Post by **brentp** » Sun Sep 07, 2014 9:11 pm

Hi,

Thanks for the update.

However, I'm not quite following your reply- it sounds like your 1st sentence contradicted the 2nd. So I wanted you to try 'frequency' mode instead of RPM as a test to see if the problem goes away.

When configured for frequency mode: does it show the signal under all circumstances, and you don't have to interrupt the signal, and so on?

L Cubed · Post by **L Cubed** » Mon Sep 08, 2014 2:36 am

OK, the issue I have had from the start is that on start-up of the RCP (power applied to unit) there is no signal in logs or sensor monitor from any of the pulse input channels.

After the unit has powered on and other sensors can be seen working in the logs and sensor monitor, I have to interrupt the pulse input signal to get it to show on logs or sensor monitor.

There appears to be no issue with the pulse inputs AFTER the signal is interrupted either by a momentary switch or physically disconnecting the input from the RCP and then re-connecting the input with the RCP unit already on.

If this doesn't clear it up I'll take another video of what I have been doing for testing.

Post by **brentp** » Mon Sep 08, 2014 4:53 am

Got that, thanks.

The experiement I wanted you to try was, If you re-configure the timer input channel to "Frequency" mode instead of RPM mode --- does it start working correctly, without having to interrupt the signal after power up?

I'm asking as a way to troubleshoot / narrow down the problem.

Post by **brentp** » Mon Sep 08, 2014 5:05 am

This is the setting I'm referring to. if you change your timer channels to this setting, does it start working correctly under all conditions?

L Cubed · Post by **L Cubed** » Mon Sep 08, 2014 5:12 am

Under that setting I get the same results posted before. Whether in RPM of Frequency mode the same thing happens.