CAT 3208 monitoring

[Ray Davis]

For my product I am locked into how the CANpod works, which is ASCII and TCP based. If your project can look like a CANpod then it would likely just work.

My understanding is that the rPi would do exactly what is needed, and that telnet server source is abundant. I am not Arduino savvy, however my Pixar buddy indicated to me that implementing TCP stack on the Arduino would be exceedingly difficult.

I will check with Cubic Labs, but this is the first I have heard that the CANpod can send over UDP.

Ray

[davidbrady]

Ray,

Thanks for checking with Cubic Labs, and thanks for hanging in there with us on this discussion. You've gone above and beyond the call of duty, and for that you get a +2 rep! Thanks!

[davidbrady]

I thought you guys might like to see the steps required to add a Fan Speed gauge to VMSpc.

First bring up the VMSpc Parameter Editor. Here's a snippet of the editor:



For my Fan Tachometer I'd start by choosing a similar PID that VMSpc already understands. In this case I chose "Engine Speed". This means I'd use the same J1578 encoding for my Fan Tach as is used by the Engine Speed PID 190. Now all I need to do is define the new PID value and assign the gauge min, max, red line, and yellow line values. In the snippet below I arbitrarily chose PID 255; I'm assuming there's some proprietary PID space available, maybe a bad assumption. I'm also assuming that what VMSpc needs to know to decode the PID is described in "Format", "Offset", and "Multiplier", which I left unchanged from what's used for "Engine Speed". This needs to be verified:



Then under Gauges I select "New Simple Gauge", choose "Fan Speed", click "left alignment", and click "show gauge name", "value, unit", and "graph":



And here's my gauge:



This may work assuming there's some proprietary PID space that I can use, also it needs to be verified with Silverleaf.

[Ray Davis]

I would NOT choose PID 255. PID 255 is a continuation PID, which indicates the next byte is a PID in the range of 256 to 511.

The PID's are arranged in an order, single byte data PID's run from 0 to 128. Double byte PIDs run from 128 to 191, and variable byte parameters run above this. This is all modulo 256, and a PID of 255 indicates an extension PID, and the next byte indicates the PID. It can be extended 3 times to give PID values up to 1024.

I don't know how Silverleaf expects you to do this, but I would assume you need to chose a PID that does not get sent in your vehicle. In that case I would chose something like 180, which is normally trailer weight, but would be a two-byte data value.

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PS: Are you looking for actual speed, or the fact that you're on high or low setting. PID 26 is already defined as "Estimated Percent Fan Speed", but expects a percentage value, so it is a single byte value. Never-mind, I see from your example that you are going to send the actual RPM, so a two byte data PID is more appropriate.