MoTeC M84 → RealDash CAN setup (Need base config / XML)

General
1

Hello everyone,

I’m trying to connect my MoTeC M84 ECU to RealDash via CAN.

Current setup:

  • ECU: MoTeC M84
  • Connection: CAN (also can use RS232 if needed)
  • Adapter: (write yours → CANable / OBD / Bluetooth etc.)
  • RealDash device: (Android / iPhone)

Goal:
Display:

  • RPM
  • Speed
  • Lambda
  • Oil pressure
  • Fuel pressure
  • Coolant temp
  • Battery voltage

What I need:

  1. Recommended CAN setup (baud rate, CAN ID, protocol)
  2. Base MoTeC transmit template (if available)
  3. RealDash XML for MoTeC (M84 if possible)
  4. Best method: CAN vs RS232 for stability

Notes:
I prefer a clean direct setup (no Arduino / no extra translator if possible).

Any help or shared configs would be appreciated.

2

I can give you some basic M84 CAN addresses.
Base address: 0E8
RPM: offset:0 Length:2 (multiplier 1, divisor 6)
Ground Speed: Offset: 58 Length:2
Lambda1: offset:10 Length:2
Lambda2: offset:12 Length:2
Oil Press: offset:24 Length:2
Engine Temp: Offset 8 Length:2
Volts: Offset:44 Length:2

2 Likes
3

I can give some notes on how to get some readings from your M84, but I’m pretty sure it depends on what sensors/readings are available in your ECU/harness.

Before I talk about my readings I’ll give you a brief explanation on how the CAN data works on the M84 (and other Gold Box ECUs).
Motec CAN data is usually customizable on most ECU’s. You can set the order in which the data is transmitted through the CAN bus. The M84 Does not have this customization, it only uses the Data Set 3 addressing. They also transmit their data in 2 byte width, so each CAN ID would have 4 readings.
e.g.:
bytes 0&1 is one reading such as RPM
bytes 2&3 is another
bytes 4&5 is another
bytes 6&7 is another
They never transmit data/readings in a single byte.

I got a pdf file from Motec directly that gave me the data order and scaling, but for some reason the data order was different on my setup so I had to sniff around to know which readings were which. I think its probably unique for each setup. I will also link a video to a Motec webinar about CAN bus so you get a better idea.

In terms of hardware and wiring I used 3 different CAN Analyzers and they all seemed to work instantly without any configuration. Waveshare USB-CAN-A, MeatPi CAN-USB, Cheap Chinese knock off analyzer that looks like the one from SEEED Studio.
You should also add a resistor between the CAN Hi and Low wires even if your analyzer has one build it (Extremely important, Otherwise you wont get any readings). This should be enough to get the readings showing on your RealDash app or any other CAN application like SavvyCAN.

I’ll attach my XML file just so you get an idea on the readings I got from my setup, My wiring harness is very basic and lacks a lot of sensors so I don’t have man.y readings (Not even oil pressure since its wired directly to an analog gauge that I have)

Get your hardware working and from there it should be easy to identify the data from the ECU. Then you would have to create the XML file to convert the data which is the time consuming part.
M84Test3.xml (2.0 KB)

https://www.motec.com.au/training/MoTeC%20CAN%20Message%20Types%20Explained%20

3 Likes
4

Thank you for your reply i would take that and do it as u said

5

thank you i would look and try