Thursday, October 25, 2007

Smaller Cap

Found a 10nF cap on an old ComputerEyesRT board (circa 1991). No idea why I still had one lying around. Swapped out the 50nF cap. Adjusted the extruder capacitor setting to 0.00000001. Note: I've got two leads on the holes for C3 and have been trying out caps by soldering to the leads. Less wear on the board from soldering and desoldering.

Re-ran the profiler. Fewer I/O timeouts and false readings. Still noticing a change in duty cycle on the heater but it's less pronounced.

I haven't looked at any of the PIC code but I'm guessing the heater is controlled by a software PWM loop. If that's the case, temperature measurements and serial communication will mess with the duty cycle. Best you can do is avoid polling too often.


nophead said...

Hi Steve,
Have you been following the forum thread:,5215,page=2 ?

andreas has posted some improved code to fix intermittent readings.

Steve DeGroof said...

Nope, hadn't seen that. Thanks.