boostDR Posted March 31, 2018 Report Share Posted March 31, 2018 Hi, Is there a way to output 0-5v referenced to MAP ? I want to remove my MAF sensor however the TCU still requires the reference signal. Kind Regards, Matt Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 31, 2018 Report Share Posted March 31, 2018 Only our Kurofune ECU has analog outputs designed for piggyback type sensor simulations. If you have one of our other ECU's then you will need to use a GP PWM, and add a basic external circuit with a 5V pullup and a R-C filter to smooth the PWM signal down into an analog looking signal. Remind me in a day or two when Im back at work I will draw a quick diagram with some recommended values & settings. Quote Link to comment Share on other sites More sharing options...
boostDR Posted April 1, 2018 Author Report Share Posted April 1, 2018 Sorry I have a Fury. Sounds good. Enjoy the Easter break. Chat soon. Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted April 1, 2018 Report Share Posted April 1, 2018 Forgive me if im not following but cant you just use a map sensor - feed it 5volts and use the output voltage ? Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted April 2, 2018 Report Share Posted April 2, 2018 @Ken Dunkley he is trying to send a simulated maf value to the trans control unit Quote Link to comment Share on other sites More sharing options...
boostDR Posted April 6, 2018 Author Report Share Posted April 6, 2018 Hi Adam. Any chance you could post that R-C cct solution. :-) Kind Regards, Matt Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 7, 2018 Report Share Posted April 7, 2018 Below will give you a response time of about 0.05sec with a ripple of 0.06V. Set aux output frequency to 1000Hz. Quote Link to comment Share on other sites More sharing options...
boostDR Posted April 8, 2018 Author Report Share Posted April 8, 2018 Done. Will post up the frequency vs voltage once I do some testing. Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 8, 2018 Report Share Posted April 8, 2018 1 minute ago, boostDR said: Done. Will post up the frequency vs voltage once I do some testing. The frequency should be fixed at 1000Hz, as above. Duty cycle is what you vary. It should work out pretty close to: 0%=0V, 50%=2.5V, 100%=5V. Quote Link to comment Share on other sites More sharing options...
boostDR Posted April 12, 2018 Author Report Share Posted April 12, 2018 I have it set up as GP PMW and 1000hz constant. Duty: 100% is 3.3v and 0% is 6.8v The PWM output goes to ground at 100% and sits at about 7v at 0%. Wondering if I’m doing something wrong. Can seem to get the required scaling. Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 12, 2018 Report Share Posted April 12, 2018 Crap I just noticed a mistake in my drawing sorry. The pull-up should have been on the other side of the 1K. Quote Link to comment Share on other sites More sharing options...
boostDR Posted April 12, 2018 Author Report Share Posted April 12, 2018 Ok, modified the cct. Works as expected now, thankyou. 15 % duty at 1kHz is 5.1v 84.5% is 0.05v response time is ok. You can see a slight ripple at the second decimal point. I might try 4kHz on the weekend and see how it goes. Matt Quote Link to comment Share on other sites More sharing options...
boostDR Posted April 13, 2018 Author Report Share Posted April 13, 2018 I've attached my Duty Cycle vs Voltage output lookup table for reference. My cct design: 1KR 510R 22uf 4000kHz constant (Aux 1) Matt MAF_VOLTAGEvsFREQ.xlsx Quote Link to comment Share on other sites More sharing options...
Gavin Magee Posted March 18, 2020 Report Share Posted March 18, 2020 Hi Guys, I was hoping to use this circuit to run a Geartronics gear display as I am using the 0-5v signal from the barrel sensor as an input for the Fury ECU for closed loop shifting. I realise an easier way would be to simply splice into the barrel sensor signal for both the ECU and the display, however I have been told by the distributor of the Geartronics system that this will not work as it will give inconsistent results (not sure why this would be the case). The current problem I can foresee is that the Fury does not allow me to output a PWM signal with a frequency greater than 300hz. Can anyone confirm the best way around this? Thanks. Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted March 18, 2020 Report Share Posted March 18, 2020 Aux 5 to 8 can not be Pulse Width Modulated (PWM) above 300Hz. Note that PWM frequencies above 300 Hz may be required to drive a tachometer for a V8 above 4500 RPM. Quote Link to comment Share on other sites More sharing options...
Gavin Magee Posted March 18, 2020 Report Share Posted March 18, 2020 1 hour ago, Brad Burnett said: Aux 5 to 8 can not be Pulse Width Modulated (PWM) above 300Hz. Note that PWM frequencies above 300 Hz may be required to drive a tachometer for a V8 above 4500 RPM. Thanks Brad, I'll switch some functions about so I can use aux 1-4 Quote Link to comment Share on other sites More sharing options...
ytubit Posted October 22, 2021 Report Share Posted October 22, 2021 Hi, been trying to use this method to drive some stock analogue temp/oil pressure gauges in an old commodore. I’ve been trying for a couple days and cannot for the life of me get the results mentioned above. hooked up exactly as above all I can get out of the aux output is a constant 6.5v when pull-up hooked to 5v or constant 12v when pull-up is to 12v. changing frequency and duty cycle does nothing. any idea ideas. I even hooked up on the bench with no gauge and same results. The pwm output doesn’t seem to do anything. On 4/12/2018 at 9:04 PM, Adamw said: Crap I just noticed a mistake in my drawing sorry. The pull-up should have been on the other side of the 1K. Hooked up as per @Adamw ecu aux is aux 1 on a thunder ecu, set to gp pwm tried constant frequency of 10-4000 with no change in output voltage. I have the cap going polarity to ground. Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 22, 2021 Report Share Posted October 22, 2021 What voltage do you get if you set Aux 1 to "Test (ON)". Quote Link to comment Share on other sites More sharing options...
ytubit Posted October 23, 2021 Report Share Posted October 23, 2021 On 10/22/2021 at 9:44 PM, Adamw said: What voltage do you get if you set Aux 1 to "Test (ON)". Hi @Adamw with the pull-up hooked to 5volts or 12volts it outputs 0 volts (it goes to ground) when set to test (ON) Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 23, 2021 Report Share Posted October 23, 2021 That suggests the aux is working then. Test(ON) is the same as having 100%DC in your GP PWM table. Have you got the activation conditions set up and the aux status runtime shows "On"? Quote Link to comment Share on other sites More sharing options...
ytubit Posted October 24, 2021 Report Share Posted October 24, 2021 3 hours ago, Adamw said: That suggests the aux is working then. Test(ON) is the same as having 100%DC in your GP PWM table. Have you got the activation conditions set up and the aux status runtime shows "On"? doh!! I had switch condition set to ignition and somehow entered 2 instead of 1 in so it wasn’t activated. I had checked the runtime value earlier and it was on so I tripped myself up along the way somehow. Working now, thanks heaps for your help @Adamw FYI, I didn’t need the RC filter to work on this early commodore. Works fine without it but wouldn’t work with it at all, which I find a little confusing. I assume I need to remove the pull-up and just run the r-c combo but it’s working good so won’t bother. Thanks again. Quote Link to comment Share on other sites More sharing options...
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