Trouble starting PIC or internal clock on 12f683?

[mackrackit]

Try changing

@ __config _INTRC_OSC_NOCLKOUT  & _WDT_OFF & _MCLRE_ON & _CP_OFF

to

@ __config _INTRC_OSC_NOCLKOUT  & _WDT_OFF & _MCLRE_OFF & _CP_OFF

[ScaleRobotics]

Oops.

Thanks Dave, and mgauthier711! I will correct that.

Walter

[PickyBiker]

Try changing

@ __config _INTRC_OSC_NOCLKOUT  & _WDT_OFF & _MCLRE_ON & _CP_OFF

to

@ __config _INTRC_OSC_NOCLKOUT  & _WDT_OFF & _MCLRE_OFF & _CP_OFF

The only way I can get it to start is with this:

@ __config _INTOSCIO & _WDT_ON & _MCLRE_OFF & _CP_OFF

Now that it starts, there is still an issue with it. I get output pulses on servos 2-4, but not on servo1. The pulses that I do get do not vary with the input pulses, they are just 2ms on 3 & 4, and 1.6 ms on 2.

I'll check to see if there is anything wrong with my setup and wiring again.

[ScaleRobotics]

The code does act funny if the input from the pulses exceeds the 1ms to 2ms range. Check your transmitter, and see if you have any channels above 100%. You might try changing them to 95% in both directions, just to make sure.

Walter

Edit:
Do you have the diodes on the three incomming receiver signals?

[PickyBiker]

Yes, the diodes are there and I get good 5v pulses just like on your web page. Current status:

all channels 85% with 0 offset and 0 subtrim.

No changes detected in output pulses.

Could the missing servo 1 pulse be because I have the WDT on? (Remember, it won't start if I set WDT off).

[ScaleRobotics]

Sorry to hear that.

Let me double check what I have when I get home tonight. I will let you know what I have, and double check my wiring to see if I differ from my schematic.

Thanks for the feedback.

Walter

[PickyBiker]

Thanks Walter.

In my circuit, I needed a pull-down resistor for pin 5. Without it the trailing edge of each pulse was badly sloped. It could be just a difference between our receivers, mine is a Spektrum AR6000.

Best,

Mike

[ScaleRobotics]

Mine were a little sloped as well. But when I tried to add a resistor, it dropped the voltage down too much for it to detect a pulse. I suppose they would all slope equally, so it should not change things too much. Or, a transistor could be added to boost the voltage.

I did notice that I had my MCLRE_ON on my circuit, but did not show it on the schematic. But you can sort of see it in the picture, with the red wire:


I used

@ __config _INTRC_OSC_NOCLKOUT  & _WDT_OFF & _MCLRE_ON & _CP_OFF

I will test with an extra receiver or two tonight, but you might try changing the osc setting, and MCLRE to what I have above, tying MCL to high, and using no resistors for the receiver in on pin5.

Walter

[mackrackit]

The only way I can get it to start is with this:

@ __config _INTOSCIO & _WDT_ON & _MCLRE_OFF & _CP_OFF

Now that it starts, there is still an issue with it. I get output pulses on servos 2-4, but not on servo1. The pulses that I do get do not vary with the input pulses, they are just 2ms on 3 & 4, and 1.6 ms on 2.

I'll check to see if there is anything wrong with my setup and wiring again.

I have not had a chance to look at the data sheet but you OSC setting is bothersome.
That outputs a clock signal I think???

[Archangel]

Hello mgauthier711,
Just saw your post, did you try this with PWRTE on and WDT off? Sometimes these PICs are a little fussy about the power rise curve and the power up timer helps.

[PickyBiker]

Pulling pin 4 to +5v and removing the pull-down resistor from the input allows it to start reliably now with
@ __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_ON & _CP_OFF

It still only puts out fixed length pulses. If I put the pull-down back in 47k, the output stops. If I add as little as 20pf to the input, the pulses stop. There is improvement however, I now get fixed length pulses on all 4 outputs.
[ATTACH][/ATTACH]
If the attachment made it, you can see my wirng and the pulses

[ScaleRobotics]

I compiled the program I had on the website, and it ran correctly for me. A couple things I notice that are different. The diodes you are using look to be different than the small diodes I used, the 1n914. The scope seems to show this difference on the input signal, as the channels never quite get back to zero voltage, although they do get pretty close. I would try the 1n914's if you have them. If not, try just inputting a single channel with and without the diode, and see what it looks like on the scope. It will still output a single channel (as servo 3). If this is the issue, a single channel without the diode should work.

I have also included a hex file, just in case there is a difference there. I used Darrels latest DT_INTS version 1.00 for mine, but it seems like the old version would have worked as well.

1.00 can be found here: http://darreltaylor.com/DT_INTS-14/intro2.html

I tried it on a FMA FS8 Co-Pilot, and a Hi-Tech Electron 6 receiver.

[PickyBiker]

Thanks for the information. I'll pick up some 1N914's and see if that's the problem.

Best,

Mike