CCP Modules and PICS

[JDR04]

Hi Folks, I'm looking for a PIC that is suitable for servo control but can also be programmed by my PICKIT2 programmer.

I'm told the pic needs to have 2 CCP modules in it but the only one I can find which is suitable is the 16F877A and 16F877. It seems a hell of a waste to use this controller to control only 1 servo???

Can anyone suggest anything else I can use please?? Many thanks..........John

[medelec35]

Hi John,
What about
16F76x
16F61x
16F62x?
It's not just about CCP channels.
You could find there are not enough pins, or memory or other features.
If it was me I would create my flowchart, compile with the bigger devices and see how much memory it took and pins required.
Then I would source a microcontroller that still has a bit of memory when compared to how much memory required and pins spare, so can continue development.
You can check Microchip selector or Steve's Flowcode V6 PicPac List

[JDR04]

Thanks Martin, I'll check that out.

[JDR04]

OK, I've scouted around and think I should have a go at using the 16F767.

To program this pic I will need to make up a small PCB that will attach to the PICKIT 2 programmer.

I,ve done a circuit and would appreciate any corrections or advice. Please see attachment. Thanks everyone....John

[kersing]

C1 has one unconnected pin.
I would not use C2, putting a capacitor on Vpp is never a good idea as it might deform the programming signal. Also, why would you connect Vpp to PGD with a capacitor?
You need a capacitor of 100nF between Vdd and Vss, close to the pins on the board.

General advice when creating a drawing:
- use dots when traces connect if possible.
- try to avoid crossing components with traces, route around them.
- make sure labels are positioned where nothing obscures them. C2 is an example of how not to do it.
- avoid placing components in-line like the left side of R4. Just placing it to the right and connecting a trace makes it clearer the component is connected to the trace.

Also, I would consider placing SIL1 vertical, it would avoid the need to loop the traces on the left above the connector. Pin1 at the top or left makes for easier reading and less chance of mistakes when hand wiring a board.

[JDR04]

Thanks kersing, appreciate your comments.

I'll redo it on Wednesday and republish it for your comments.

Thanks again...much appreciated....John

[JDR04]

Hi folks, I've redrawn the PICKIT 2 ICSP schematic the way kersing advised....I think.

If you guys could take a look and give your comments/advice it will be well appreciated. Have I connected the two Vss up correctly?

When I do the PCB I will use a 28 Pin ZIF socket and keep all tracks as short as possible. Can this also be done on a solderless prototype board as well?

Thanks a lot......John