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View Full Version : CANbus to analog gauge converter - Does this exist? Anyone want one?



digitalsolo
01-18-2018, 11:47 AM
Hey all,

So I'm designing a bunch of electronics for my '65 Mustang project, and one of the things I've been working on is a bunch of custom CANbus stuff. Specifically , I am making a BCM setup similar to an InfinityBox, but more tailored to what I want and about 1/10th the price. Along with this I'm building a gauge display that reads CAN data from my ECU (AEM Infinity) and shows it on some OLED gauges.

This got me thinking about my Speedhut gauges (analog sensors) and it wouldn't be too much effort to output signals to them as well, so that the ECU ran them based on its local data. Does anyone make something like this? I'm just curious if it's worth my time to make this flexible enough for other people to use it (it could be made to run factory gauges based on CAN data from an ECU for example) or if someone else already has something like this available?

All my stuff is open source, I'm not trying to start a business or anything, just helping out the community. Here is the code for my current OLED gauge display (still a work in progress, though fully functional): https://github.com/analoghan/CAN_Gauges

Right now I'm planning on adding some warning LED outputs and probably a tie in to my CANbus BCM hardware to be able to display things like brake light status, etc. for troubleshooting to the gauge code. I'm still debating adding the analog gauge control output to it (hence the reason for this post).

Thoughts?

blitzer454
01-18-2018, 02:09 PM
Dakota Digital sells an OBD II interface module that works with their gauge set, but I doubt it would work with other manufacturer's gauges. I like your idea but in order for it to work with a wide range of gauges you would need to recreate the gauges sending unit signal and I don't think there is an industry standard for this signal.

I can't say that I have ever looked at a sending units signal to see what it was, but I can imagine that it's probably just a voltage that scales based on what ever it is measuring. So recreating a voltage swing based on the OBD PID data would be the easy part, the hard part is matching the output impedance to the gauges input impedance, and again since I'm not aware of a standard for this signal, that impedance isn't going to be the same for everyone. But through trial and error I'm sure you can get it to work for the Speedhut gauges, that is once you figure out what kind of signal it requires.

I just looked at your build thread, nice car. :cool: I like you OLED gauge display very cool. I'm also designed my own BCM although it cost me way more than 1/10 of the cost of the InfinityBox. You'll have to tell me how you plan on doing that. :dunno:

dontlifttoshift
01-18-2018, 02:25 PM
Doesn't Speed Hut already do this?

Nevermind, just saw that you have an AEM ECU. In my limited research, every ECU manufacturer decided they wanted to use the own language. The hardest part (to me) will be getting AEM to divulge that information as it seems like nobody wants to share it.

digitalsolo
01-18-2018, 04:31 PM
My discussion was mostly talking about running the gauges off of the data. Reverse engineering CAN data is easy. AEM publishes all of theirs, so they're super easy.

CapSS92
01-19-2018, 12:03 PM
Something like what this guy is doing?

https://ls1tech.com/forums/conversions-hybrids/1889182-instrument-cluster-conversion-proof-concept.html

digitalsolo
01-26-2018, 10:52 AM
Kinda. My intent was to read the data from a stock or aftermarket PCM and run stock gauges off of that data. Seems like not a lot of interest. I'll continue on with building it for my own purposes, anyway.

parsonsj
01-26-2018, 07:16 PM
One of the things I'd like to be able to do is send data on GM's network. I'd like to be able to send an AC request to the E67 ECM, etc.

I'd also like to be able to program my InfinityBox customers' boxes. I have several custom ideas, but haven't gotten around to figuring out how to do either.

parsonsj
01-26-2018, 07:42 PM
I went to read your source code (I write air traffic control software for the FAA), but the link didn't work..

digitalsolo
01-26-2018, 11:54 PM
Weird, must have been a copy/paste issue on my post with the link. Fixed. :)

udloze
02-02-2018, 05:22 AM
Volvo penta has a product for there marine applications that converts CAN signal into analog to run analog gauge packages. I should be able to find specifics in a service, tech manual if you would like more info.

wickedmotorhead
02-07-2021, 11:26 AM
Bringing up an oldie, but did you ever come up with a solution? I have a customer that has a Holley hp ecu and speedhut analog guages and i would like to get away from all the redundant sensors and just adapt the ecu can mesages to the analog signals for each of the gauges. Thanks!

Vimes
02-08-2021, 02:06 PM
Bringing up an oldie, but did you ever come up with a solution? I have a customer that has a Holley hp ecu and speedhut analog guages and i would like to get away from all the redundant sensors and just adapt the ecu can mesages to the analog signals for each of the gauges. Thanks!

I've not used them before but Lingenfelter (https://www.lingenfelter.com/mm5/merchant.mvc?Screen=SRCH&priceranges=1&searchcatcount=1&srch_all=1&onlyone=1&Search=can2-002) makes one. 4 gauges per unit, multiple units allowed. It can also be used to trigger stuff.

wickedmotorhead
02-08-2021, 05:24 PM
I've not used them before but Lingenfelter (https://www.lingenfelter.com/mm5/merchant.mvc?Screen=SRCH&priceranges=1&searchcatcount=1&srch_all=1&onlyone=1&Search=can2-002) makes one. 4 gauges per unit, multiple units allowed. It can also be used to trigger stuff.

I saw that one but i believe its only for oem ecus that follow sae protocals which i understand the holley does not follow. I may give them a call though to see if they can accomodate.

icemanrd19
02-11-2021, 09:11 PM
What about the other way? Hooking up 3 or 4 analog signals to convert them to can bus? My hp tuners hub only has 2 5v reference locations and I need more.