jbelk7 
Hi,
I'm currently trying to control a small motor using PWM.
The problem I'm having is getting my signal out. Here's what I'm working with:
DDRB = 0xFF;
TCCR0A = (0<<FOC0A) | (0<<WGM01) | (1<<WGM00) | (1<<CS02) | (1<<CS00); // Set PWM Phase Correct Mode with CLK/1024 prescaler
OCR0A = 50; // just chose a random value
How do I get this wave out to PORTB?
Thanks,
Jason
Wrong forum. Should be the regular AVR forum, not the XMega forum. Hopefully, a moderator will move it.
Jim
clawson 
How do I get this wave out to PORTB?
jbelk7 All apologies, folks. I didn't mean to post in the wrong forum. I'm still very new to this.
I'm using the AVR Butterfly board which uses the Atmega169 uC.
I was going to assign something to a port. Example
PORTB = OC0A;
I just don't know exactly where my PWM is or the proper way to to go about this.
clawson Well apologies to you. The mention of "butterfly" in the title should have told me it was a mega169. But if you look at page3 34-35 of the Butterfly user guide where the schematics are you can first see that timer 0's PWM output (OC0A) is on pin PB4 but you can further track this to see that it's connected to the center pin of the joystick. As this is usually open circuit you should be able to gain access to the signal without it being interfered with as long as you don't touch the joystick.
Note that Joe Pardue (smileymicros) has a PDF that shows which of the Butterfly signals are available for general use - search out a copy if you don't already have a copy.
Butterfly Alternate Pin Use
http://smileymicros.com/download...
jbelk7 Hi Folks,
I've been working diligently, and here's what I have now. I have a small DC motor connected to a 9V source, and isolated from the Butterfly.
I've written a code to divide the clock frequency of 2 MHz by 64. I think I've set the registers and OCR1A so that OC1A switches at 125 giving me about half of my 9V??
Everything compiles, but when I turn on the board, The motor makes 1 revolution and stops. Here's my code. Anyone have any advice? Thanks for your time.
#include
int main (void)
{
DDRB = 0xFF;
TCCR1A = (1<<COM1A1)|(1<<COM1A0) | (1<<WGM10) |(1<<WGM11) ; // Set PWM Phase Correct Mode with CLK/64 prescaler
TCCR1B = (1<<WGM13) |(1<<CS11) |(1<<CS10);
OCR1A = 125; // If it counts to 256, this is about half
for(;;) {}
return 0;
}
I have example projects for the Butterfly to control PWM and motor speed. You can download 'C Projects Source Code Next Gen' from my website Downloads menu.
Also look at:
https://www.avrfreaks.net/index.p...
and
https://www.avrfreaks.net/index.p...
and
http://www.societyofrobots.com/m...
Smiley
jbelk7 I really appreciate all the feedback guys. I've gone from basic C programming on a computer to embedded programming, and the learning curve is steep. And Smiley, I'm very grateful for and impressed by how much support you provide for the Butterfly. I've pencil marked and dog eared your book to death.
bryank I really appreciate all the feedback guys. I've gone from basic C programming on a computer to embedded programming, and the learning curve is steep. And Smiley, I'm very grateful for and impressed by how much support you provide for the Butterfly. I've pencil marked and dog eared your book to death.
It is always great to hear things like this. Sometimes I feel like I'm howling in the wilderness.
Thanks,
Smiley
Sometimes I feel like I'm howling in the wilderness
