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Gear signal to PDM???

PostPosted: Thu Oct 26, 2023 2:02 pm
by Clean RC
Hello.

Once again I am stumped on a can related item.. I have been trying to use the can signal from the M150 to the PDM to trigger the reverse lights as the mechanical switch on the trans is not an option with the sequential dog box set up.. I do have a gear sensor on the box, and its wired into the M150 with the information going to the C125. So I know what gear the car is in on the dash. I would like to use that signal to trigger the reverse lights if at all possible..

I have been searching this forum for a while trying to see if anyone had some ideas on how to do this. I downloaded the M150 general DBC and opened it in a program from Kvaser. The format does not make sense to me as this is not really my strong suit.

I see the signal that is on 0x64D bitpos 48, length 4,factor 1,offset 0,minimum -8,maximum 7

how do i use this in something the pdm will understand??

Thank You again for all the help, this forum provides..

Scott.

Re: Gear signal to PDM???

PostPosted: Fri Oct 27, 2023 4:39 am
by David Ferguson
The easy way to do this: Use the Motec device with the most programmable CAN output (your C125 dash) to send a message to the PDM (just use an unused CAN address). Program the PDM to receive this value, and use it to activate the reverse lights. This is very simple for folks that due this routinely (like your MoTeC dealer, who should be helping you).

If you would upload your C125 and PDM configurations, I will be happy to make that change for you as an example. If you need to do more, you will have a example to work from.

Re: Gear signal to PDM???

PostPosted: Fri Oct 27, 2023 12:57 pm
by Clean RC
David.

Thank You for the response. I do not have a Motec dealer, as the used race car came with the PDM32 and C125.. On the last car I did, I was able to use the reverse switch hard wired to the pdm. No such luck with this one. I just rewired this car to accommodate the upgrade of the M150 from the old car (that was rolled and destroyed) and to fix some of the wiring issues from an older build.. I Thank You for you help.. I am always willing to learn new things... So if you give me an outline I will try it.. I am also happy to compensate you for your time..

Scott.

Re: Gear signal to PDM???

PostPosted: Fri Oct 27, 2023 4:40 pm
by Stephen Dean
Hi,

Try these files.

Re: Gear signal to PDM???

PostPosted: Fri Oct 27, 2023 4:44 pm
by David Ferguson
Here are your configs with the changes that I think will work.

First, I looked at your PDM Global Setup CAN Inputs. I see that messages 0x118 - 0x11E were selected. From the M1 Help for "ECU CAN Transmit", we know that the M1 sends data to 0x118 - 0x11A if enabled. So 0x11B would be the first available unused CAN messages (we could also use a different CAN address like 0x500 - 0x520).

So since I know reverse gear is typically a gear value of -1, I started to setup the PDM CAN Input for a 16 bit signed value, but later I found I could not compare "Gear equal -1" (PDM Manager converted that to "Gear equal 0"). So I switched to get getting an 8-bit unsigned value, and decided I would convert the values sent by the dash to be positive values.

Looking that the C125 Dash Manger help for "Calculations->Gear Detection..", I see that gear could be a value from -5 to 9, to account for automatic transmissions. So to be as flexible as possible the values -3 and -1 could both represent Reverse selected. So I will add 5 to the Gear value that I transmit to the PDM.

So starting with the Dash Manager, look at Connections->Communications->CAN2->Dash to PDM 0x11B (use the "Edit" button with that template selected). This will show you an example of transmitting a single byte of the gear channel offset by adding 5. So with this offset R will be value of 2 or 4.

Next look at the PDM Manager under CAN Inputs. You will see I added CAN.Gear as an 8 bit value starting at offset 0 on address 0x11B. Then under Functions I added Functions.Reverse Gear Active and test for gear to be either 2 or 4. Finally, I modified Output Pins for Out.Reverse Lights to use Functions.Reverse Gear Active.

I think it will work, but you will need to load and test. Let us know if it works or you have any questions.

Re: Gear signal to PDM???

PostPosted: Tue Oct 31, 2023 3:56 am
by Clean RC
Disregard last message.. I had to update the pdm software on my laptop to match the software on my desktop to be able to read and load the configs... Thank You as always.. I am still learning every time I play with this system.. Thank You again for all the help..

Installed the dash and the pdm configs into the car today... Works like a charm.. Thank You Mr Dean, and Mr Ferguson for all the help and knowledge.. Many Thanks again.

Scott