Garrett 712120 VNT Hella 6NW 008 412 actuator.

Klatta Klatta

185

10-29-2009, 02:12 PM #39

(10-29-2009, 12:21 AM)300SD81 Started writing the code for this thing, has anyone confirmed if the actuator cares about the PWM frequency or not? Is it actually sampling the frequency, or just the average analog voltage?

Unfortunately, it DOES care about the frequency. Not sure what its range is, but I remember it didn't work at just any old frequency. Sad

I don't think it'll work on an analog voltage either.

(10-29-2009, 12:21 AM)300SD81 The lowest I can get my PWM on the uC is 3+KHz unless I lower the clock speed (64Mhz/4/16 = 1MHz timer frequency, but it the timer for PWM is only 8 bits). Might try feeding it an analog voltage this weekend, and if that dosen't work, I'll just bit-bang the pwm...

You could always get a better PIC Wink

That definitely sucks though. It's annoying to have to bit-bang stuff when you have a hardware peripheral that should be able to do it.

(10-29-2009, 02:06 PM)300SD81 Did you get any voltage readings off the original car when you had it on a scope?

Yep! But they're on my old phone, which I won't be able to get to till tonight. I'll try and post them if I get the chance.

(10-29-2009, 12:38 PM)winmutt +12v PWM fried one of the controllers (bloated a resistor) and the TTL of 5v does nothing.

Sounds to me like that was a capacitor. Still that's very strange.

A note to all about soldering on this board... it is a ceramic PCB. In my experience with ceramic PCBs at work, they are EXTREMELY easy to shatter. They are VERY sensitive to differences in temperature. With the PCBs we had made, when you put a soldering iron on a pad while the rest of the PCB is at room temperature the PCB would shatter. You will probably have to use a reflow oven (or toaster oven Wink

) to get it to work, and who knows how much of that other stuff would get screwed up in the process. That's my $.02 since it could very well be just the PCBs we had made, and this one is much sturdier. However, I think that's why there are those blocks/pads to wire the PCB to the housing. You can wirebond those wires quickly and the thermal mass of the block/pad will keep the PCB itself from getting warm.

This post was last modified: 10-29-2009, 02:19 PM by Tymbrymi.

John Robbins
'05 E320 CDI - 118k - Faaaaaast!! Angel

'87 300TD - 317k - Cracked head... but an OM606 is on the way! Undecided

'79 300SD - 295k - Bad engine = project car!