CAN Bus Communications Decoded: Cause a Variable You Are Looking For to Change
Cause a Variable You Are Looking For to Change
01.15
00:00 | - The next step is where we're going to start narrowing in on the parameters we've got on our target list. |
00:06 | With our CAN bus data stream being displayed on our PC, we now want to physically cause the parameter we're looking for to change in the real world and look for a corresponding change in the data stream. |
00:17 | At this point, it's very helpful to generate a spreadsheet recording the data stream PIDs and data byte locations. |
00:24 | You can then update this as you proceed through your target parameter list. |
00:28 | Check out the resources section of the course where you'll find an example spreadsheet that you can use as a template. |
00:34 | Causing a real world change to the parameter you're hunting for is usually pretty self explanatory, revving the engine in the case of engine speed for example. |
00:41 | But sometimes you can only indirectly cause a parameter to change such as oil pressure. |
00:46 | In these instances you need to think about how the parameter will respond to the real world change that you're making and look for that change in the data stream. |
00:56 | In the case that you see multiple data bytes in the stream changing, seemingly in response to your input, note them all down in your spreadsheet as the next step of the process is where we'll determine the parameter scaling and this should weed out any byte locations that aren't correct. |