Small pin-count device for generating output frequencies when triggered

[JimAvanti]

Henrik,

Without hardware PWM I don't really need to go any further with this. It is working good enough for what I need it for and the tone range is good. I knew this would be a very small program, but I was hoping to have the capability of a constant tone for the duration of the trigger, but I can live with short sound bursts. I purchased 10F322 chips first, but PBP didn't support them and I couldn't figure out MPLAB-X.

I will be using two of these chips set to different tones so I can hear either or both when they trigger. Maybe at some future time I will figure out MPLAB and be able to program the 10F322's (Hardware PWM with adjustable Duty for LEDs or adjustable Freq for sound). I did figure I could just use ADRES directly, but I don't need to do anything else with these anyway.

Thanks for all your help.
Jim

That's correct, no CCP module in this one (I didn't check that previosuly). And there's no interrupts either.

What sort of frequencies are you talking about?

BTW, in your code, there's no real reason to waste one of the PICs 23 bytes of RAM, out of which PBP uses most, to copy ADRES to Tone - just use ADRES directly.

/Henrik.

[HenrikOlsson]

If you need to be able to change the tone "continously" then rearanging the code slighty might make it a little bit better, the glitch should be in the us* range:

Main: 
   GO_DONE = 1		    ' Start the conversion
   IF Trigger THEN       
      Sound SPK,[Tone / 4 + 50, 1] 
   ENDIF
   WHILE GO_DONE : WEND	' If trigger isn't 'on' we need to wait for the ADC.
   Tone = ADRES
Goto Main

*Depending on how much time SOUND needs to "set it self up".

/Henrik.

[Dave]

Hey Jim, If all you are looking for is an A/D to Oscillator output have a look at maybe using some Linear Tech. TIMER BLOX. They make 2 different VCO's to cover the range from 29uHZ to 977 HZ and 1 for 488HZ to 2Mhz. They are in 6 pin SOT packages. Just a thought.....

[JimAvanti]

Hi Dave,

I just looked at the datasheet for the LTC6990 and it does look like it could work for what I need. I would have to test how the frequency ranges sound first, but it seems to have everything I need (OE to trigger it and Freq can be controlled by a POT manually). I'll have to test it and let you know.

Thanks,
Jim

Hey Jim, If all you are looking for is an A/D to Oscillator output have a look at maybe using some Linear Tech. TIMER BLOX. They make 2 different VCO's to cover the range from 29uHZ to 977 HZ and 1 for 488HZ to 2Mhz. They are in 6 pin SOT packages. Just a thought.....