MoTeC Global Forum

Greetings all.

We are using a M130 ecu, AIM solo 2 DL, and a LTC-D. The firmware is based off motorcycle drag and Motec USA has done all the build changes for us to date.

We have been using the same communications templates for over a year with no problems.

We added a Gripone IMU to the can bus, and Motec USA built it into the firmware. There are no issues seeing the output from the IMU in the ecu and (Motec) recorded data. The IMU is transmitting on 500, 501, 502 and receiving on 480.



I have done a caninspector capture and can see all the IMU messages when it is plugged in. There is nothing else using that address that I can see.

When the Gripone IMU is connected some of the channels displayed on the AIM dash drop in and out every 3-4 seconds. Not all the channels, only coolant temp, ecu voltage, oil temp, and both lambda channels. All these are still working fine internally in the ecu and logged data.

The AIM solo 2 is exporting GPS and G-meter data to the ecu and these drop in and out also when the IMU is plugged in. So some of the channels ecu>dash are dropping out, but all of the data dash>ecu is dropping out.

Pic below is screen shot from G-meter showing drop out.



I have attached the can inspector data as well.

Both AIM and Motec USA have looked into this and are telling me it's on the others side.

Any input would be much appreciated!

What CAN ID do you send the dash to ECU data? Have you considered making it less than the Grip IMU to prioritize that communications. Are all of the GripIMU transmissions being processed by the M1?

What happens if you change the Gripone IMU to transmit on 0x700 (1792)?

The coolant temp, oil temp and ecu voltage is on 0x649. The lambda is 0x651. ECU>Dash

The GPS is 0x680, the acceleration sensor is can 4 offset 0,2,4. Dash>ECU.

All of the IMU transmissions are received by the ecu with no gaps or errors.

I have not tried changing the addressing on the IMU.

What is the CAN Bus utilisation? Do you have the CAN Bus error channels logged?

From the CAN log you can see the 0x680 message from the Display stops for about half a second while all of the messages related to the channels you say stop in the Display continue to be sent.

It's pretty hard to say what would be causing it, my only thought would be that as the IMU is sending out blocks of messages back to back at 100Hz maybe the display isn't handling it. I can't comment on the AIM device, but I have seen plenty of CAN devices that can't handle receiving back to back messages. You can see below the time between messages is between 115us and 200us, so that is an effective transmit rate of somewhere between 4000Hz and 8000Hz for the block.

Stephen Dean wrote:What is the CAN Bus utilisation? Do you have the CAN Bus error channels logged?

The Can Bus diagnostic channel is logged at 10hz. I am not clear by that you mean by "utilisation", I don't see a channel with that label.

In the Dash Manager, if you go to Connections | CAN Bus Error Counts, this brings up a window that lets you enable the CAN Bus Receive and Transmit Error Count channels, as well as the CAN Bus utilisation for each of the CAN Buses.