Feeler: Open Source OBC Firmware

[mdimillo]

This has peaked my interest. Who's responsible for this project? I'd be interested in buying one or helping write some software for it.

[Nomade30]

Sorry guys homework has been overwhelming me, I hope to pound out some of the missing basic functions over spring break.

[daandaman]

So but how about the hardware... is that tested OK now? In other words, can "we" start producing the boards? Changing firmware so to speak is possible after install anyways...

[benemorius]

So but how about the hardware... is that tested OK now? In other words, can "we" start producing the boards? Changing firmware so to speak is possible after install anyways...

The hardware has basically tested ok. By that I mean it's a suitable reference design and one would end up with usable boards if one built some based on the current design. It isn't perfect though.

There are a few things I wanted to change before ordering another batch of boards and I just haven't found the time to do the new layout. I actually thought I was going to tackle this the other week but I became distracted and made a new ADS interface instead. This next batch is expected to be the first one that people are encouraged to build. It just doesn't quite exist yet.

It would probably be good to go ahead and get an idea of how many people will be wanting one from the next batch. Not only do I need to know how many boards and parts to order, but it may also prove useful for me to see exactly how much you guys want me to find the time to do this. When there is no active discussion it becomes easy to lose track of how much interest there is, and subsequently, it becomes easy to lose interest myself.

This has peaked my interest. Who's responsible for this project? I'd be interested in buying one or helping write some software for it.

Consider it a community project. Once the hardware materializes, the firmware should lend itself well to community development. Your contributions will be welcomed.

Once I test the next batch of boards I'll be able to supply openOBCs to anyone who wants one. I just need to sit down and get it done.

Thanks for voicing your interest. It brings us one step closer to getting the next revision out.

[daandaman]

Daandaman 1pc

[mdimillo]

I could help with the firmware when the time comes.

[silverbullet21]

I'm in for my obd1 e36! Any ballpark idea of cost?

[chikinhed]

Official list of people waiting to order an Open OBC kit:

1. Chikinhed
2.
3.
4.
5.
6.
7.
8.
9.
10.

Sent from my GTX3582R

[bry195]

Official list of people waiting to order an Open OBC kit:

1. Chikinhed
2. Bry195 (how much)
3.
4.
5.
6.
7.
8.
9.
10.

Sent from my GTX3582R

updated

[mdimillo]

Would I be able to apply this in my E34? If so, toss me on the list. I know they're pretty similar systems but idk how similar. Mine looks like it has 15 buttons? Does that sound right? Would it be an easy conversion to an E36 OBC? Will it screw up my Check system on the cluster?

EDIT: Looks like I'd have to do some serious modifications. That's a shame though, maybe I could work on hooking it up and creating an E34 version for us guys

[Mark185]

Would I be able to apply this in my E34? If so, toss me on the list. I know they're pretty similar systems but idk how similar. Mine looks like it has 15 buttons? Does that sound right? Would it be an easy conversion to an E36 OBC? Will it screw up my Check system on the cluster?

EDIT: Looks like I'd have to do some serious modifications. That's a shame though, maybe I could work on hooking it up and creating an E34 version for us guys

The data bus on the E34 is different. Making this work on an E34 is not a reasonable thing to ask these guys. A tremendous amount of work has gone into figuring out how the E36 OBC and data bus work. There is a guy on the forums that has built an electronic interface box for E34 that will allow you to connect temp and pressure sensors and display their values on the LED display in the gauge cluster.

http://www.interfaces4beemers.net/cluster-display.html

[mdimillo]

The data bus on the E34 is different. Making this work on an E34 is not a reasonable thing to ask these guys. A tremendous amount of work has gone into figuring out how the E36 OBC and data bus work. There is a guy on the forums that has built an electronic interface box for E34 that will allow you to connect temp and pressure sensors and display their values on the LED display in the gauge cluster.

http://www.interfaces4beemers.net/cluster-display.html

Wow that's an awesome device.. I understand asking for compatability is a huge request, I was just merely asking if the two were similar units but I guess not. Perhaps that's something I could contribute towards in the future as I'll be definitely exploring this Check Control System etc. and it's related components.

[Spyke]

I would love one for my OBDI e36 as well... I almost never touch mine in stock form, it would be nice to put it to work.

[silverbullet21]

Sooo im thinking new thread with a list of interested buyers and approximate cost along with a description of exactly what would be purchased (for the obc) as well as a short description of current and future functions on this board that we'd purchase?

Im thinking that this would be the best way to drum up support and get a good list going. Maybe with a link to this thread as well?

[mdimillo]

Wouldn't be a bad idea silverbullet. Just went through all 48 pages and observed this thing go from concept to completion. Great work guys. One question though, I'm no EE expert but I understand a lot of electronics, what is a pullup resister?

[Nomade30]

IIRC from my high school classes, a pullup resistor will make sure that a signal is at the desired voltage.

Also here is my github, I lost of a lot of the refactoring I did in order to setup recording averages easier, stupid harddrive crash.
https://github.com/damonearl/openobc-de

[mdimillo]

IIRC from my high school classes, a pullup resistor will make sure that a signal is at the desired voltage.

Also here is my github, I lost of a lot of the refactoring I did in order to setup recording averages easier, stupid harddrive crash.
https://github.com/damonearl/openobc-de

Sweet, I'll check that out when I get some time. And ah, awesome thanks. Lots of stuff makes sense now, lol.

[daandaman]

Official list of people waiting to order an Open OBC kit:

1. Daandaman
2. Chikinhed
3. Bry195 (how much)
4.
5.
6.
7.
8.
9.
10.

[benemorius]

Ok guys, I'm gonna try to post a quick update. I've updated the schematic from the first prototype and I think I'm about ready to lay out the next board.

Feature-wise it's pretty much the same as the first one, but not everything is in the firmware yet and we're still not up to factory-equivalent operation. The price is expected to be about $150 for an assembled board with alpha-quality firmware installed. ETA on the assembled boards is not less than 3 weeks. ETA on a release-quality firmware is anyone's guess.

I'm attaching the preliminary schematic for review. If any features are to be added or removed from the next revision, the time to discuss it is now. I'm trying to assemble something resembling a feature list but I'm really out of touch so it is likely incomplete. As far as other features go, ask away. I can't promise anything but it won't hurt to bring them up again.

has:
all factory features
usb host
usb device (ft232 - for programming and serial output)
accelerometer
micro sd slot
jtag
vehicle diagnostic interface
expansion headers (gpio, analog input, analog output, spi, i2c, can, uart)

has not:
gps
bluetooth
wifi
gsm
magnetometer

It is hoped that most of the excluded features can be added to the firmware later by supporting the use of usb devices via the usb host port.

[daandaman]

......
It is hoped that most of the excluded features can be added to the firmware later by supporting the use of usb devices via the usb host port.

Hi Benemorius,

How many analogque inputs and analogue/digital outputs will it have as standard?

I'd like to display two wideband lambda signals, (programmable output Innovate LC-1)

and at least 2 or 7 high/low outputs:

(6 for racelogic traction control adjuster integration... its an 3 wire (GND, 5V+ and Signal knob which has 6 steps varying from 0-5 volts with 1v increments, which im planning to do with 6 relays each having their own resistor. The relays then will be powered with the outputs of the OBC!! ) Either this or someone would need to help me to make a program that enables stepped output of 1 OBC output.... which would only use 1 output then.

And one high-low output for my ride-height adjusters (an air solenoid valve)

Will all this be possible? That would be so awesome... I wouldnt need to integrate switches into my dash then!!!

[benemorius]

Hi Benemorius,

How many analogque inputs and analogue/digital outputs will it have as standard?

I'd like to display two wideband lambda signals, (programmable output Innovate LC-1)

and at least 2 or 7 high/low outputs:

(6 for racelogic traction control adjuster integration... its an 3 wire (GND, 5V+ and Signal knob which has 6 steps varying from 0-5 volts with 1v increments, which im planning to do with 6 relays each having their own resistor. The relays then will be powered with the outputs of the OBC!! ) Either this or someone would need to help me to make a program that enables stepped output of 1 OBC output.... which would only use 1 output then.

As it is now there are two analog inputs and one analog output plus at least 8 digital inputs/outputs and 4 relay outputs.

The digital pins go straight to the microcontroller, so they can't be used with 12V signaling directly. This is fine if the stuff you're hooking up is 5V but you'll need a bit more circuitry to get it to, say, output a 12V high signal to something. The relay outputs can drive relays directly but the digital outputs would need to go through a transistor to get enough current.

So, you could use the relay outputs to drive 4 of the relays, and two digital outputs with drive transistors and protection diodes to drive the remaining two relays. Stepped output on a single pin is easy enough using PWM or the analog output, but unfortunately you can't output above 3.3V directly with this approach since that's what the micro is running on. Relays are a fairly bulky solution here, but they may well be the most straightforward to implement.

And one high-low output for my ride-height adjusters (an air solenoid valve)

This would be treated like a relay if you mean that the output drives a solenoid valve directly. Or a pair of transistors may be needed if you need to output a 12V high signal to a control unit instead.

Will all this be possible? That would be so awesome... I wouldnt need to integrate switches into my dash then!!!

Sure sounds like it, though the exact amount of external circuitry needed may not be clear yet.

[LagWagon]

Sorry.. didn't want to crawl through all the posts, I am guessing by open source you mean that the C source code is available to us to extend/modify if we are programmers?

Was thinking I could put my oil/water temp functions into the OBC (http://extremeelectronics.co.in/micr...crocontroller/)
and toss the gauge..

[stefanom3]

Still accepting people on the waitlist ?

[daandaman]

Official list of people waiting to order an Open OBC kit:

1. Daandaman
2. Chikinhed
3. Bry195 (how much)
4. stefanom3
5. spyke???
6. silverbullet21???
7. jdantuono???
8.
9.
10.

[benemorius]

Sorry.. didn't want to crawl through all the posts, I am guessing by open source you mean that the C source code is available to us to extend/modify if we are programmers?

Was thinking I could put my oil/water temp functions into the OBC (http://extremeelectronics.co.in/micr...crocontroller/)
and toss the gauge..

Yes, the firmware is all written in C++ with the lowest level library routines in C and a tiny smattering of assembly where it can't be avoided. It is intended to be as easy to code for as mbed or arduino. Reprogramming the firmware on the OBC will require only a USB cable and computer, and bricking won't be possible.

I'm sure there will be a lot of interest in doing gauge functions. Almost certainly that will be a part of the official firmware at some point, though it remains to be seen who will write it. I don't have any gauges or extra sensors myself.

Still accepting people on the waitlist ?

For sure! If enough people formally declared their interest I'd have to yield to the will of the majority and make the time to finish the next revision.