NSFW

I've been wanting something that fits into a standard 52mm gauge pod and uses a screen like this one with a microcontroller like this one plus a canbus interface. Peripherals optional, I'd be happy with just power, ground, and CAN.

The electronics is a little over my head but if you're interested in doing that part, I'm perfectly happy to do the software part. My main goal is basically to have a unified gauge that just tells me that everything is OK, or which thing is not OK, but there's other fun stuff I'd like to do as well, like a side-scrolling AFR chart. And since the screen supports touch, the driver could swipe through different gauges, which would be neat.

Separately, but relatedly, and simple enough to do on my own, I'm itching to build something that will log a bunch of data from the stock PCM and send it over CAN, using this module from Pete Sonntag (OBDX, LS Droid) and either Arduino MKR or Seeed XIAO for the CPU and canbus stuff. The parts are all here, and hoping to get it working between xmas and new year's since I have the week off.

LSswap

That round display and controller look awesome. That controller looks like it has bluetooth. So now, all you need is to get the data from GM and send it over the bluetooth. The platform I designed supports canbus and bluetooth and there already exists a library for OBDII on arduino, so I don't see a problem getting data from a GM ECM from the OBDII port and sending it to the bluetooth of the round dial displays. If you are already playing with one of those displays and controllers, I can provide you with the hardware to get the info from OBDII and output to bluetooth. I haven't done it myself yet, but suspect it's doable with my new board.

Let me know if you're interested.

Does anyone know if there is an OBDII simulator? That would be the easiest way to get his going.

LSswap

Found this: OBDII simulator
Actually, now that I'm looking, there are lots of them out there.

and there seems to be some free stuff out there https://www.instructables.com/Arduino-OBD2-Simulator/

turboesky

This is a really cool project. Would it be possible to use this to take Class 2 serial data from an early LS1 5.7 and convert it into Racepak Vnet data? I am trying to use an early IQ3 that doesnt have the built in OBD2 module (street version).

LSswap

I'm not sure. Maybe this thread has something you're looking for: https://ls1tech.com/forums/conversio...j-1850vpw.html

crazybenn

Hi! but if i plan to use my DIY dash with a termX (not Max) there's no way to read the CanBus? or do i need to buy an external device to make it possible?

LSswap

The hardware I described can read the CANBUS on the termX, but I don't have the list of can messages for the native bus. Some people out there have it. If you get info on the native messages, LMK, maybe I can help you then.

crazybenn

well i can sniff the CanBus via a Teensy 4.0, I can say the first line look like a clock.. i think i found the MAT , maybe i found the CTS but not sure.. maybe the TPS also... 132 different adress! found the "topic" of a line is easy... for the formula, it's a mind blowing task! ... what's happen if i swith the canbus to Racepack instead of Holley... the Term X have only one CanBus port!

Kippdipp

Please post log/trace

Kippdipp

I've disassembled some firmware using Ghidra and found the attached function which is from the 7" Holley display which receives and sends CAN data to and from a Holley Terminator X.. Looks like index 0x90 corresponds to AFR from what I can tell. No idea if the command, target ID and other bits are similar to racepak but if they are then AFR would be 0x1F204000 (with serial masked) on the native bus (I think).

Edit: Found this string that does suggest Holley CAN does run at 1Mbps "sbin/ip link set can0 up type can bitrate 1000000 restart-ms 50 listen-only off"

TrendSetter

check out pages 91 and up
https://www.nhraracer.com/Files/Tech...ions_Rev10.pdf
is that what youre looking for?

Project GatTagO

iTrader: (7)

The Holley Standard CAN doesn't share the CAN ID or the structure with Racepak. The Standard Holley CAN is 1Mbps.

Andrew

LSswap

Thanks. The is the same data as the original link I provided on the first post in this thread. Unfortunaltely, the original link no longer works. The link you provided points to the same document that describes the racepak protocol. I fixed the link in the first page.

Kippdipp

Take this with a grain of salt but from what I can gather reverse engineering the digital dash firmware, the normal Holley CANBUS IDs are similar to the Racepak protocol and also runs at 1mbps but has a slightly different structure and values for the ID:

Bits 28:28 – Command Bit (=0 for broadcast i think)
Bits 27:25 – Target ID (I think 101= broadcast)
Bits 24:22 – Source ID (haven't confirmed if 010 is hefi like Racepak but pretty sure it is)
Bits 21:11 – Target Serial (used as a channel # index, index #1 is RPM)
Bits 10:0 – Source Serial Number (11 bits)

So assuming the structure above, the CAN ID for RPM with the source serial number masked out (using 0xfffff800) would be 0x14100001.

For the data:

• First 4 Bytes: This would be the Value field. These bytes are combined into a 32-bit value. I haven't found any evidence of a scale or offset factor being applied.
• Second 4 Bytes: This would be the Status field. Usage is TBD.

RPM = (RxMessage.Data[1] << 8 ) | RxMessage.Data[0];

Example:
If the CAN message has:

CAN_ID = 0x14100001
RxMessage.Data[3] = 0x0
RxMessage.Data[2] = 0x0
RxMessage.Data[1] = 0x09
RxMessage.Data[0] = 0xC4

---------------
uint32_t RPM = RxMessage.Data[0] |
(RxMessage.Data[1] << 8) |
(RxMessage.Data[2] << 16) |
(RxMessage.Data[3] << 24);

Then:
RPM = 2500 RPM

My car is currently not operational or else I'd log and confirm. Anyone have a Holley CAN trace / log they can share?

Also think I found all of the other channel #'s but don't know if they directly correspond to the channel # index, but assuming they do then attached is the full list I found in the firmware.

LSswap

That looks promising.

Obviously this needs to be bechtop tested and confirmed. I have a Simulator that can emulate all necessary sensors and cam and crank signals to run a Holley on a desktop. I also have a canbus processor that can interface with the Holley to test these codes. I don't have a Holley however.