There is a conditioner in the gauge cluster. If the car is not moving you get nothing. Once you hit something around 10mph it will take injector duty and rpm and the gauge on the cluster will follow. Its a 12 volt square wave I believe from the DME to the cluster.
Im going to guess and say that these values are passed to the OBC implicitly (on a regular cycle) and the OBC uses it to trend MPG.
Unfortunately, they're out of stock of pre-built ones, or I would have already . I'm not skilled enough to solder SMD components!
The OBC itself gets a signal from the injectors that tells it how many litres per hour you're using. It then averages that over road speed to give you your MPG. As far as I can tell, the OBC is expecting a 6 Cylinder engine, but will work with a 4, but show the wrong value (9.3L/100km in reality shows as 22.5L/100KM on the OBC).
Here's what my scope showed me
High Load, full throttle
Nav8Xwj.png
Cruising, 50% throttle
t5wyLOv.png
Idle, 0% throttle, stand still
7wJUPNs.png
I'll trust that you confirmed the frequency and amplitude makes sense. I intercepted white/black to the cluster and give it 12 volts with varying duties and the MPG works on my obd1 car but I dont have OBC black/white is tach I believe and its distributed to a couple different modules including the OBC I believe. I at least have it on my on board display. I believe tach is at a much lower voltage.
I know that one of the modules takes the two signals and then dumps the values into "can" in an implicit "cyclic" message on obd2 gauge cluster. I think maybe it was thaniel who was playing with and or describing this years ago. My memory is too foggy so look at thaniels can bus stuff and you will find it buried in there but its really just some clues that might guide you. I think im changing my mind. I think the obc mastered the telegram to the cluster but it could be vice versa.
Sorry its been way too long. What I can tell you is that the white with black from the DME to the cluster will control the needle on an obd1 with a 12 volt signal with a varying duty or frequency but the cluster wont react to anything until the car is moving. Sorry, wish i was more help.
Got some questions for ya'll, I tried googling this and came up with nothing, but didn't someone once mention getting an openOBC to communicate with a TPMS?
How can one go about correcting the MPG reading on the OpenOBC? Ever since I installed it, I think it has been way too generous with my mpg.
I have installed led lights everywhere on my car except for low/high beams and foglights. Even though I bought these "canbus" compatible bulbs that advertise eliminating the problem of your car thinking a bulb is out that didn't work. The strange thing is that sometimes I get taillight1 and 2 out message, and other times it just says "check..." Anyways I am assuming it is the check control module itself that determines the correct draw for light bulbs and there is no way of changing that (and no I am not going to add inline resistors) so disabling these errors on the OpenOBC should prevent the messages from ever showing as well as the check light in the IC correct?
'97 M3, Estoril blue, 2 dr, euro 6-spd, EFR 9180 divided T4 .92 IWG, RK tuning, CP 8.5:1 pistons, Eagle rods, Schrick cams, L19 11 mm ARP studs, O-ringed block, Supertech stainless/inconel valves, Supertech springs & Ti retainers, ported head, S54 oil pump/pan, 80 lb. injectors, OBD1 intake manifold, Steedspeed twin scroll T4, 3.5" SS exhaust, eBoost2 EBC, HFS-4 W/M injection, AEM Failsafe, Zeitronix data logger, Racelogic TC, OpenOBC w. ethanol %, Ireland Eng. engine mounts, UUC black tranny mounts w. enforcers, UUC twin disc feramic, ARC-8's, MCS 2-ways, Z3 rack, Rallyroad strut bar, X brace, Eibach sway bars, Ground Control LCAB bushings, Bimmerworld RTAB's, Powerflex subframe bushings, 210 4-clutch LSD, Stoptech BBK, titainium shims, steel braided lines, brake cooling ducts.
Great thank you! I have successfully disabled all of my rear light warnings (due to led's). Next I just want to get rid of the oil pressure option since I don't have anything that can read that. Also I would love to figure out how to make the turn signal stalk function as normal, is there any fundamental thing in the way of that coding wise?
I think the stalk was figured out in Nov-Dec of last year.
'97 M3, Estoril blue, 2 dr, euro 6-spd, EFR 9180 divided T4 .92 IWG, RK tuning, CP 8.5:1 pistons, Eagle rods, Schrick cams, L19 11 mm ARP studs, O-ringed block, Supertech stainless/inconel valves, Supertech springs & Ti retainers, ported head, S54 oil pump/pan, 80 lb. injectors, OBD1 intake manifold, Steedspeed twin scroll T4, 3.5" SS exhaust, eBoost2 EBC, HFS-4 W/M injection, AEM Failsafe, Zeitronix data logger, Racelogic TC, OpenOBC w. ethanol %, Ireland Eng. engine mounts, UUC black tranny mounts w. enforcers, UUC twin disc feramic, ARC-8's, MCS 2-ways, Z3 rack, Rallyroad strut bar, X brace, Eibach sway bars, Ground Control LCAB bushings, Bimmerworld RTAB's, Powerflex subframe bushings, 210 4-clutch LSD, Stoptech BBK, titainium shims, steel braided lines, brake cooling ducts.
It's not WIFI, it is the alarm or memo on symbol.
The add on board was made by Xobloof. The Arduino set up was put together from info on the SR20 forum and is not needed with the OpenOBC.
Last edited by chikinhed; 04-19-2017 at 04:57 PM.
'97 M3, Estoril blue, 2 dr, euro 6-spd, EFR 9180 divided T4 .92 IWG, RK tuning, CP 8.5:1 pistons, Eagle rods, Schrick cams, L19 11 mm ARP studs, O-ringed block, Supertech stainless/inconel valves, Supertech springs & Ti retainers, ported head, S54 oil pump/pan, 80 lb. injectors, OBD1 intake manifold, Steedspeed twin scroll T4, 3.5" SS exhaust, eBoost2 EBC, HFS-4 W/M injection, AEM Failsafe, Zeitronix data logger, Racelogic TC, OpenOBC w. ethanol %, Ireland Eng. engine mounts, UUC black tranny mounts w. enforcers, UUC twin disc feramic, ARC-8's, MCS 2-ways, Z3 rack, Rallyroad strut bar, X brace, Eibach sway bars, Ground Control LCAB bushings, Bimmerworld RTAB's, Powerflex subframe bushings, 210 4-clutch LSD, Stoptech BBK, titainium shims, steel braided lines, brake cooling ducts.
Finally got my PCB and all the parts.
I find it very hard to put all the parts in the correct place and keep them from moving before tossing them in the oven.
For example the SD-reader has such small pins, how can I ever position them correctly & making sure my solder paste doesnt short the pads?
Help would be very nice!
Thanks guys
Did you guys ever get the ds2 protocol fully implemented? I have a ton of stuff defined for it. Most of it all comes in a single packet too so its very fast. I have the various tx packets, defined rx packets for everything. Voltage, ect, engine speed, load(mg/strk), injector pulsewidth, icv %, ignition angle, iat, STFT, vanos angle, vehicle speed, *ignition angle retard due to knock, etc, etc
Also have defined adaptation reset packets for knock corrections, idle speed correction, lambda, throttle adaptations.
It would be great if we could have access to the OBD2 data on the OpenOBC, maybe a couple at a time. I'd like knock and ign timing knock retard.
'97 M3, Estoril blue, 2 dr, euro 6-spd, EFR 9180 divided T4 .92 IWG, RK tuning, CP 8.5:1 pistons, Eagle rods, Schrick cams, L19 11 mm ARP studs, O-ringed block, Supertech stainless/inconel valves, Supertech springs & Ti retainers, ported head, S54 oil pump/pan, 80 lb. injectors, OBD1 intake manifold, Steedspeed twin scroll T4, 3.5" SS exhaust, eBoost2 EBC, HFS-4 W/M injection, AEM Failsafe, Zeitronix data logger, Racelogic TC, OpenOBC w. ethanol %, Ireland Eng. engine mounts, UUC black tranny mounts w. enforcers, UUC twin disc feramic, ARC-8's, MCS 2-ways, Z3 rack, Rallyroad strut bar, X brace, Eibach sway bars, Ground Control LCAB bushings, Bimmerworld RTAB's, Powerflex subframe bushings, 210 4-clutch LSD, Stoptech BBK, titainium shims, steel braided lines, brake cooling ducts.
It's actually DS2 protocol and not obd. It is sent via K line but it's different and BMW specific. I'll look into what it takes to program custom functions and if it seems straight forward enough I'll buy and test. Or chikinhed if you are good with it, I can give you the info and you can test out.
- - - Updated - - -
Sending 12050B03 ( checksum included) should get a 29-byte reply.
Last edited by busterhax; 06-12-2017 at 11:11 AM.
I am not a programmer unfortunately. There are others on here that could easily put this together.
'97 M3, Estoril blue, 2 dr, euro 6-spd, EFR 9180 divided T4 .92 IWG, RK tuning, CP 8.5:1 pistons, Eagle rods, Schrick cams, L19 11 mm ARP studs, O-ringed block, Supertech stainless/inconel valves, Supertech springs & Ti retainers, ported head, S54 oil pump/pan, 80 lb. injectors, OBD1 intake manifold, Steedspeed twin scroll T4, 3.5" SS exhaust, eBoost2 EBC, HFS-4 W/M injection, AEM Failsafe, Zeitronix data logger, Racelogic TC, OpenOBC w. ethanol %, Ireland Eng. engine mounts, UUC black tranny mounts w. enforcers, UUC twin disc feramic, ARC-8's, MCS 2-ways, Z3 rack, Rallyroad strut bar, X brace, Eibach sway bars, Ground Control LCAB bushings, Bimmerworld RTAB's, Powerflex subframe bushings, 210 4-clutch LSD, Stoptech BBK, titainium shims, steel braided lines, brake cooling ducts.
I think the only DS2 comms that are currently being used are for getting the coolant temperature from the instrument cluster. I have also seen some door lock and unlock functions but I haven't tried them. So DS2 is still very much on the TODO list, especially for engine parameters.
I have been gearing up to take a swing at it. In addition to a working OpenOBC, I also have a tinyADS interface and a laptop but I haven't tried hooking it all up yet.
If you take a look at the OpenOBC code on github, you can see that there are some DS2 templates setup for talking to the different modules. They just don't do anything useful yet (except for the functions noted above).
https://github.com/benemorius/openOBC-devboard
DS2 files are in "lib/DS2/"
E36 module files are in "lib/E36Diag"
https://github.com/benemorius/openOB...g/E36Kombi.cpp
The file "lib/E36Diag/E36Kombi.cpp" shows how to query coolant temp from the instrument cluster.
I would love to see your notes/defines if you don't mind sharing.
Out of curiosity, what year is your E36? Did you snoop on its DS2 bus to create the files you have?
Sweet!
I have a '95 but am hoping that the DS2 stuff is similar at least.
I think the OBDII cars have a slightly simpler k line circuit that use one less line, and not as strict timing requirements.
Hoping that the messages themselves will cross over somewhat from '95 to '96 and up.
Crossing fingers, but not holding breath.
How hard do you think it would be to display serial data from a datalogger (Zeitronix ZT-2) on the openOBC display, Maybe have a separate page displaying two or three different sensor data points?
'97 M3, Estoril blue, 2 dr, euro 6-spd, EFR 9180 divided T4 .92 IWG, RK tuning, CP 8.5:1 pistons, Eagle rods, Schrick cams, L19 11 mm ARP studs, O-ringed block, Supertech stainless/inconel valves, Supertech springs & Ti retainers, ported head, S54 oil pump/pan, 80 lb. injectors, OBD1 intake manifold, Steedspeed twin scroll T4, 3.5" SS exhaust, eBoost2 EBC, HFS-4 W/M injection, AEM Failsafe, Zeitronix data logger, Racelogic TC, OpenOBC w. ethanol %, Ireland Eng. engine mounts, UUC black tranny mounts w. enforcers, UUC twin disc feramic, ARC-8's, MCS 2-ways, Z3 rack, Rallyroad strut bar, X brace, Eibach sway bars, Ground Control LCAB bushings, Bimmerworld RTAB's, Powerflex subframe bushings, 210 4-clutch LSD, Stoptech BBK, titainium shims, steel braided lines, brake cooling ducts.
It doesn't look too bad.
I think there is an unused UART on pins p0.15 and p0.16 which map out to pins 4 and 5 on the SPI0 header. It would need an RS232 transceiver to interface with the ZR-2.
The big unknown I guess is the protocol used. But 232 is pretty easy to snoop on and decode.
Software wise, clone one of the tasks and layout the screens. Then write a UART driver, parser and connect them all.
Bump. Has anyone done anything new with the openOBC?
'97 M3, Estoril blue, 2 dr, euro 6-spd, EFR 9180 divided T4 .92 IWG, RK tuning, CP 8.5:1 pistons, Eagle rods, Schrick cams, L19 11 mm ARP studs, O-ringed block, Supertech stainless/inconel valves, Supertech springs & Ti retainers, ported head, S54 oil pump/pan, 80 lb. injectors, OBD1 intake manifold, Steedspeed twin scroll T4, 3.5" SS exhaust, eBoost2 EBC, HFS-4 W/M injection, AEM Failsafe, Zeitronix data logger, Racelogic TC, OpenOBC w. ethanol %, Ireland Eng. engine mounts, UUC black tranny mounts w. enforcers, UUC twin disc feramic, ARC-8's, MCS 2-ways, Z3 rack, Rallyroad strut bar, X brace, Eibach sway bars, Ground Control LCAB bushings, Bimmerworld RTAB's, Powerflex subframe bushings, 210 4-clutch LSD, Stoptech BBK, titainium shims, steel braided lines, brake cooling ducts.
The open OBC is such an awesome thing. I wish it wasn’t lost and forgotten about.
I finally connected a fuel pressure sender up to the openOBC. It works like a charm and is within one psi to my datalogger sensor reading
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