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18LF2520 TMR1 for PWM

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camerart

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Hi,
I've been trying different PWM settings mainly on the 18LF4431 PIC, and it's to complicated for me.
Also having thought about what I need for 6x PWM, I think a simpler TMR type program will be ok.

What I am trying is to set a TIMER LOOP (using TMR1, unless there are other suggestions) to time a 20MS 'SERVO PERIOD' LOOP, then as the LOOP starts, switch ON/OFF RB0-RB5 in sequence for up to 2MS each . The 'DUTY ON' time will be set from inputting 6 times using USART.

Here is a program I've been trying from an earlier one on a 16F648 PIC, which of course has lots of differences.

It nearly works, but I'm puzzled why the TMR1H/L keep clearing?

Camerart.
 

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camerart

Active Member
Hi,
I've tried again, with the original program from a 12F683 PIC, and now it runs :)
There are two toggling PINS one in a LOOP and one in the interrupt. I've used the PIR1 bit as a switch, is this ok?
C.
 

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camerart

Active Member
The reason it didn't.... The config bits were wrong for a 4Mhz crystal... I just regenerated... Also TO8BIT isn't correct... It's TO16BIT... Works okay here... 20.45mS period...
Hi,
I had to abandon TMR1 because it clashes with another section of program to be added, which is written also using TMR1.
C.
 
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