Keypad use with C127

[the_bluester]

I do have one further question actually. The RPM input via CAN was not correct and I have hopefully sorted that, with a divisor of 10 on the input message, does that literally result in his RPM reading according to the PDM being divided by 10?

I am wanting to add an engine running condition so we can make a few outputs conditional like preventing the starter motor from operating if the engine is over say 300 rpm.

[Stephen Dean]

That's correct, as it is a 8 bit number the maximum value that can be transmitted is 255, so you have to scale some values to get them to display correctly, i.e. the Engine Speed value has to have a divisor to get an adequate range in the displayed speed.

[the_bluester]

Thanks, that is what I though, and with the 255 value the greatest RPM it will register is 2550 which is fine for what we want to do.

I was going to hold off on that function until he has the car running so we can test for what the highest cranking RPM is warm with a fresh battery so I can set the function up on about 100RPM more than that cranking speed. Hopefully that should avoid any false detection of the engine running so we don't have interrupted cranking as it starts, or continued cranking when it actually has started.

Thanks for your help, safe to say the owner is getting excited when "Extra" stuff starts working, and it makes me keener to get my own too.

[the_bluester]

And finally, thanks for the assistance all. I finally got to lay my hands on the Motec gear in my mates car on the weekend and got it all working the way we wanted.

Took a while to work out why I could not get RPM off the CAN bus to his PDM for a couple of telltale functions (And next up, to prevent cranking while the engine is already running) On a small screened laptop is is surprisingly difficult to see the difference between 118 hex and 11B hex.

As soon as I spotted that and got my head around the flow of the boolean stuff (For instance, his telltale flashes warning lights if he stops the engine and leaves the headlights on, which I used an "Engine running" function to test for) and the function for the telltales was "If left headlights = true OR right headlight = True, AND engine running = false" it did not take long to work out that the AND needed to be on each line so "If left headlight = TRUE AND engine running = FALSE, OR right headlight = TRUE AND engine running = FALSE" was what was required. I could make it work with one half of that (One headlight only) but anyway!

All very interesting stuff to configure.