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microRusEFI issues with AN pins affected by aux reuse

Posted: Tue Jan 25, 2022 4:08 pm
by Creesic
I was attempting to get the MRE to read my AEM AFR output when I discovered many of the pins don't work properly.

Pin 32, for whatever reason, wouldn't take in the 5v signal from the gauge, so I looked for other ones.

With ignition turned on, pins 28, 32, 36, and 40 all would go to 3.3v. I'm not an EE, so I'm not exactly sure if that's how they're supposed to function, but nothing would be read when hooking anything up to those pins.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:19 pm
by AndreyB
Pin 32 is av6. Let's figure out why does it not work for you. Please link your tune. Please confirm you had power cycled ecu after setting change. Please confirm no FATAL indicator

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:28 pm
by Creesic
https://rusefi.com/online/view.php?msq=845

I always power cycle. I've updated to yesterday's FW. No errors.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:29 pm
by AndreyB
Please post a photo of the wiring around MRE. Please compare digital multimeter reading with raw voltage gauge if we have raw voltage for that sensor. If we do not we shall add it really quick.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:31 pm
by Creesic
Not sure what exactly you want to see, but I double checked before making this post with pin 36 floating. Once I turn on ignition, it immediately jumps to a steady 3.3 volts.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:35 pm
by Creesic
Oh. I forgot to mention I ended up using pin 19. Pin 19 worked fine as an input from my gauge.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:43 pm
by AndreyB
We are discussing pin 32 right not 36?

Loose wires reading does not mean anything, stuff has to be connected. AT inputs are expected to read voltage but we focus on av6 pin 32 here right?

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:47 pm
by Creesic
I mean sure, but from other discussion it appeared that all four will behave similarly. Since I'm using pin 19 for my AFR, I should be able to utilize pin 32 for something else right? Can I try using it for my tach? If so, I'll go ahead and hook it up for testing.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:49 pm
by Creesic
Naw, nevermind, wrong type of pin. I could maybe hook up a power supply to pin 32 to test.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 4:54 pm
by Creesic
I'll just splice it. I'll let you know how it behaves in a moment.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 5:11 pm
by Creesic
Pin behavior when floating - 3.3v on ignition and only ignition. Not ACC.
Pin behavior when provided voltage from the AFR gauge - Multimeter shows the pin is reading the correct voltage both in ACC and ignition key positions.
When I remove power from the gauge, nothing on ACC, but ignition makes the pin read 1.85v. (Did this just to try)

In Tunerstudio, I have the AFR input to read 0v as 10 and 5v as 19.98 as per the AEM manual.

When on ACC with the gauge functioning, the AFR reads 10.8 in TS and 14.7 on the physical gauge. When I turn on the ignition, the gauge in TS dumps down to 9.67 for 14.7 and when the AEM gauge errors out on the lean end (17+) it sits at 9.73 AFR in Tuner Studio.

Hooking up to pin 19 instead of 32 negates this issue entirely. I will now test this with pin 36.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 5:18 pm
by Creesic
Pin 36 exhibits the exact same behavior.

Re: MRE issues with AN pins

Posted: Tue Jan 25, 2022 5:48 pm
by AndreyB
Creesic wrote:
Tue Jan 25, 2022 4:47 pm
Since I'm using pin 19 for my AFR, I should be able to utilize pin 32 for something else right?
By the way your preference is to talk in connector pins while my preference is to talk in terms of functional designators.

Open question which specific board has what specific resistors R30 R84 R85 R86 populated. Open question is these AV work regardless of corresponding Rxx status.
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I've made a change to interactive pinout to at least mention aux reuse a bit. https://github.com/rusefi/rusefi/commit/9da536c4332cd24c103ccea901811830b45fdf16

Dron and Jared are the experts on this aux reuse part of MRE.

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Tue Jan 25, 2022 6:25 pm
by mck1117
@Cressic, can you take a good photo of the front of your ECU's board?

@Dron_Gus, this looks like we're failing to turn off fault detection on those output channels on the TLE8888. Can you check?

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Tue Jan 25, 2022 6:50 pm
by Creesic
CF55408C-D423-4298-9A3B-88E18C939FEF.jpeg
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Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Tue Jan 25, 2022 6:54 pm
by AndreyB
This board has all four resistors. If I read the cryptic explanation right it's asking to NOT have 0R resistors for analog to operate
image.png
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let's remove a couple of these resistors and try again on channel where we remove a resistor?

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Tue Jan 25, 2022 7:26 pm
by Dron_Gus
Short to ground diagnostic is not configurable and always enabled.
Screenshot from 2022-01-25 22-20-26.png
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Pull-down for open load diagnostic is disabled in SW.
If external source for these inputs can be affected by 100..300uA of diagnostic current - then DFB* lines should be cut.
Screenshot from 2022-01-25 22-19-43.png
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Another solution is to put these outputs of TLE8888 to on state as open load current is disabled in on state. This is possible only if external mosfets are not populated. My 0.5.0 MRE come with these mosfets in zip packet.

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Tue Jan 25, 2022 7:35 pm
by Dron_Gus
Dron_Gus wrote:
Tue Jan 25, 2022 7:26 pm
If external source for these inputs can be affected by 100..300uA of diagnostic current - then DFB* lines should be cut.
20220125_223218.jpg
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Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Wed Jan 26, 2022 1:42 am
by Creesic
Should I cut those traces? Lol

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Wed Jan 26, 2022 1:54 am
by AndreyB
Creesic wrote:
Wed Jan 26, 2022 1:42 am
Should I cut those traces? Lol
please consider removing R84 or R85 per https://rusefi.com/forum/viewtopic.php?p=44206#p44206

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Feb 04, 2022 7:19 pm
by Creesic
AndreyB wrote:
Wed Jan 26, 2022 1:54 am

please consider removing R84 or R85 per https://rusefi.com/forum/viewtopic.php?p=44206#p44206
Which one do I have to remove to make AN6 (pin 32) work?

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Feb 04, 2022 7:26 pm
by mck1117
see schematic above, AV6_MCU is connected to R86

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Feb 04, 2022 10:27 pm
by Creesic
Well I pulled R86 and it still seemed to behave like it did before. Sat at 3.45v floating.

Trying to use this pin as a launch control switch.

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Feb 04, 2022 10:31 pm
by AndreyB
Electricity is magic, floating magic does not mean much.

Many or most switches require a pull-up, is there a pull-up somewhere in this picture?

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Feb 18, 2022 3:33 pm
by Simon@FutureProof
Would like to confirm this is an issue.

Avi Moore on slack confirmed this was an issue on all 4 Aux reuse pins as it is making low power signals like lambda sensor inputs unusable.(AV6 is default for that :? )

I believe there is already a ticket open for this from some time back when I first spotted it.

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Feb 18, 2022 3:42 pm
by MHTSOS
If we cut the DFB lines like Dron_gus suggested is there any drawback if we don't intend to use the 5090 low side switches?

Στάλθηκε από το VOG-L29 μου χρησιμοποιώντας Tapatalk


Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Feb 18, 2022 4:44 pm
by Simon@FutureProof
I have cut the detection lines to the TLE8888 before with no downsides but did not want to do that unless someone was having issues.
There are some traces just to the right of the additional drivers that do the detection, it all still works with the detection lines cut.

IMO if it is impossible to disable this then it is a reason to move away from the TLE entirely for any revisions of the MRE.

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Jul 15, 2022 8:36 pm
by martin89
hello today i tried remove rezistors to have AN6 AN8 AN9 AN10 working i did not cut any traces and i see in tunerstuio valu show 2,9V when i feed 5V to input, i have potentiometer connected and it seems prety linear like wrong scaling.

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Fri Jul 15, 2022 8:40 pm
by martin89
hi, today i remove all resistors to have all four analog working, i connected one pushbutton to GND with pullup to 5V and one potentiometer to them, but their value (AN8 AN9) oes only up to 2,9V , on potentiometer i see it looks prety linear, is there any known scaling issue? do i need o cut those traces?

Re: microRusEFI issues with AN pins affected by aux reuse

Posted: Mon Jul 18, 2022 8:06 am
by martin89
it seems like i have some kind of software scaling issue because when i asign AN8 to oil pressure it reads right up to 5V as expected