FREQOUT 4mhz

[Michael]

Not having any luck. I know the piezo is good -- I've tested it.

I'm probably missing something in set up or some register that needs to be modified?

I just put in --
PWM portc.4,50,6500

Piezo is 6500 hz. Hearing nothing.

PIC is 16C72, 8 bit antique.

[Michael]

Don't know if PWM is my only option. FREQOUT can't be used and SOUND is a sine wave right?

[Michael]

and that should be 127, not 50 for duty cycle -- typo

[Michael]

I think it may be this crap piezo I'm using --

https://www.ebay.com/itm/US-Stock-50...72.m2749.l2649

hard to work with. maybe someone can suggest an inexpensive one that they know works well. need low cost as this may be a product idea. 6500 hz is pretty high as well.

[richard]

Don't know if PWM is my only option. FREQOUT can't be used and SOUND is a sine wave right?

wrong
from manual

SOUND outputs TTL-level square waves. Thanks to the excellent I/O characteristics of the PIC MCU, a speaker can be driven through a capacitor. The value of the capacitor should be determined based on the frequencies of interest and the speaker load. Piezo speakers can be driven directly

I just put in --
PWM portc.4,127,6500

Piezo is 6500 hz. Hearing nothing.

pwm does not do what you have expected

@4mhz clock pwm output is 6500 cycles @200 hz


a 6500hz resonator can be driven at frequencies other than its resonant frequency

your chip has a pwm/ccp module , you could use HPWM

to get maximum noise you can drive the resonator bipolar mode between to output pins antiphased

I notice those resonators you linked have no connecter leads , how good is your soldering ?
they don't work if they have been cooked

[Michael]

Ok Richard thanks. I'll try SOUND and stick with it and yes, those transducers are something I've never dealt with -- they're a pain. Going to try something else.

[Michael]

Do you think these will work on a PIC output with the SOUND command at 2300 hz ? At least they're 5V.

https://www.ebay.com/itm/Gfortune-15...UAAOSwErFZ0-ze


Having problems getting piezo diaphragms and driver circuits to be very loud. barely hear them in fact. --Thank you

[mark_s]

Those are self resonating. They will buzz at 2300hz when 5 volts is applied. Look for "transducer".

Something like this
https://www.ebay.com/itm/AT-12-Piezo...gAAOSwZd1Vewuj

[Michael]

I realized that after posting -- thanks. Will try that part you suggested. Can't believe something so simple has been such a headache.

Thanks.