Two 16F84 pics using one piezo?

[mister_e]

i can't comment on the SOUND command but if it's like PWM, sometimes the pin return to Input, sometimes to Output state so...

As producing sound is not a big job, i suggest you to build a few line routine for that. That way, you'll be able to reach the exact resonnance frequency and get the maximum SPL of your piezo.

Don't worry, the suggested method is safe.

[sougata]

Hi,
Use a series limiting resistor and give the port to port via capacitor scheme a try. You bet you can produce interesting effecting where one PIC generates the sound and the other modulates it.

A recommendation would be to use a non-polar cap. Or two electrolytes back to back.

BTW in this scheme both has to be an output.

Regards

Sougata

[Rubicon]

O.K then I'll give it a go and report back.

I suppose if I really didn't want any beeping conflicts I could make the program check the pin for an input voltage before a SOUND command and if there is a voltage present then use another routine.

Rubicon.

[Rubicon]

With both PICs PORTA.1 pins set as outputs and making them again outputs after each SOUND command just to be sure I tried the PortA.1-1uF ceramic capacitor-piezo-PortA.1 and PortA.1-10uF electrolytic capacitor-piezo-capacitor PortA. schemes.

With both schemes I got the regular beep, a slightly louder regular beep and if both LED banks were completely in-sync the beeping sped up by a what sounded like a factor of four. That was it.

Many thanks again,

Rubicon.