Control a Radio PLL with a PIC

[RayL113]

What if I want to use a cb channel switch instead of an encoder? The first four pins have a logical progression of 0000 to 1111. Couldn't I use this like a Gray code encoder? Count increase would equal up and count decrease would equal down. What do you think?

[cncmachineguy]

You can use that, you can use the thing you already have, its up to you. They both CAN work. With the CB switch you will only get 16 changes per full revolution. If this is enough then use it. It will prolly still have noisey output so de-bouncing will still be neccessary. Now if you can get this, I have used many, they work really well.

Let us know how you are getting along on this project. Have you blinked a LED on port A yet?

[Archangel]

Search here . . .

http://www.mouser.com/Electromechani...ers/_/N-39xfc/

Seriously Cheap !

[RayL113]

You can use that, you can use the thing you already have, its up to you. They both CAN work. With the CB switch you will only get 16 changes per full revolution. If this is enough then use it. It will prolly still have noisey output so de-bouncing will still be neccessary. Now if you can get this, I have used many, they work really well.

Let us know how you are getting along on this project. Have you blinked a LED on port A yet?

I think I'm going to try to use the channel selector approach. Using RE1 thru RE4 as the inputs. I read in the manual that there is a command that will sample the designated pins and store the result in a register of my chosing. The problem I am having trouble sorting out in my head is what should I do when the count goes back to 0000 after 1111 and vice versa. And still have the count continue up or down. Is there some way to like have a loop restart when this limit is reached?
Just messing with it as time allows. So not much progress. Still learnig the PBP commands and uses. And yes, got LED's blinking like crazy using machine code, but haven't tried it wih PBP yet.
Thanks for the helps Guys!

[cncmachineguy]

well let me say I think its the more complicated way, but hey that makes it more fun. I would guess you will have to read the count on the selector, compare it to the last count, If it is higher, add 1 to the freq, if its less subtract. To cross the zero, you will have 2 choices when at 0 of at $F. from o you will go to 1 or $F, and from $F you will go to 0 or $E. So just check for that when you get to those counts.

I would think you will have to really spin the selector VERY fast to miss any counts, so I would start with that scheme and see how it works. Don't forget you may need to de-bounce the inputs.

[RayL113]

Thanks Bert. Should I use the IF...THEN string? Something like this;
Start
PEEK CHSEL CHSELVAR
IF CHSEL = 0000 THEN CHECK0
IF CHSEL = 1111 THEN CHECK1
ELSE LOOP

LOOP
PEEK CHSEL CHSELVAR
If CHSEL > CHSELVAR Then UP
Else
PEEK CHSEL CHSELVAR
IF CHSEL < CHSELVAR Then DOWN
Else
GOTO Start

UP
PLLDATA = PLLDATA +1
MOVLF PLLDATA PLLDATAOUT
GOTO Start

DOWN
PLLDATA = PLLDATA -1
MOVLF PLLDATA PLLDATAOUT
GOTO Start

CHECK0
IF CHVAR = 0001 THEN UP
IF CHVAR = 1111 THEN DOWN
ELSE LOOP

CHECK1
IF CHVAR = 0000 THEN UP
IF CHVAR = 1110 THEN DOWN
ELSE LOOP

Of course I didn't include all the defines. Am I on the right track?

[cncmachineguy]

Seems like the basic idea. Not sure what language that is but the idea looks about right

[RayL113]

Seems like the basic idea. Not sure what language that is but the idea looks about right

Uh Oh. Thought it was PBP. What did I do wrong?