Programmable square wave oscillator possible with a PIC??

[royalmp2001]

I need to design a programmable square wave oscillator
(fixed/variable/sweeping frequencies upto about 35KHz) with
programmable timed on/off intervals...for instance so many minutes on,
then so many minutes off, then on again, etc.

I know nothing about PIC programming, but I have a PIC programming
board that connects to my pc, and if I know that it is possible to do
this with a PIC, I will get a book on PIC programming.
Thanks
royalmp2001

 

[KenHopkins]

There are several ways to do this. You can simply set an output port
high, then low again with a variable delay in between. You could use
the hardware timers to the same effect. You can also feed internal
oscillator to output pins. There are many options depending on which
micro you are using and what frequency it is running at. Try the Apps
notes at http://www.microchip.com


Ken
www.claymore-electronic.co.uk

 

[Bob Monsen]

royalmp2001 wrote:

I need to design a programmable square wave oscillator
(fixed/variable/sweeping frequencies upto about 35KHz) with
programmable timed on/off intervals...for instance so many minutes on,
then so many minutes off, then on again, etc.

I know nothing about PIC programming, but I have a PIC programming
board that connects to my pc, and if I know that it is possible to do
this with a PIC, I will get a book on PIC programming.
Thanks
royalmp2001

The PIC12F683 has a PWM generator. That would be the right choice, I
think. Then, the software only has to program the generator, based on
whatever controls you use.

I bet there is an appnote at microchip that spells it all out in large
letters.

--
Regards,
Bob Monsen

If a little knowledge is dangerous, where is the man who has
so much as to be out of danger?
Thomas Henry Huxley, 1877

 

[Rich Webb]

On 5 Jul 2005 06:50:10 -0700, "royalmp2001" <royalmp2001@hotpop.com>
wrote:

I need to design a programmable square wave oscillator
(fixed/variable/sweeping frequencies upto about 35KHz) with
programmable timed on/off intervals...for instance so many minutes on,
then so many minutes off, then on again, etc.

I know nothing about PIC programming, but I have a PIC programming
board that connects to my pc, and if I know that it is possible to do
this with a PIC, I will get a book on PIC programming.

This page http://www.myplace.nu/avr/minidds/ has links to the schematics
and the assembler source for an easy to build signal generator based
around an Atmel AVR AT90S2313 (a very early AVR chip).

As written, it does not sweep or do programmable intervals but it is
written to be controlled by a PC over an RS-232 link (executable
provided). You could build on the basic design to make it natively
programmable or you may be able to put the controlling smarts on the PC
side.

I breadboarded it up a few years ago and it does work as advertised.

--
Rich Webb Norfolk, VA