So I build this circuit (scroll to bottom of page).
I made the same circuit as shown, but I used an LM358 and 5V arduino supplies. It works (yay!) but there is an annoying overlay of a high-pitched tone. So if I speak into the mic, it is my voice + annoying tone. All my cap + resistor values are correct, I double checked. If it helps:the overlay tone is ~868Hz, according to my tuner.
Is it the op amp that I'm using? The power supply difference?
Well, you're getting away with a lot of stuff The circuit is really designed to operate from split power supplies. By connecting the op-amp to +5V and 0V you are going to get a lot of distortion.
Try adding another 100k resistor from the '+' pin of the op-amp to its power supply (5V).
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The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons
It'd not works, link you posted shows OPA powering with +-9V.
Nothing wrong with a chip , it was design for:
"Single Supply Quad
Operational Amplifiers"
and they say:
"can operate at supply voltages as low as 3.0 V "
What is an error?
You have to change a circuitry when you powering single supply.
+input of the OPA has to be biased to half of power voltage, one more resistor 100kOhm required
to be connected between +input and +5V
And capacitor in the negative feedback, would be helpful to prevent HF osculation.
It's 8.2 Ohm, my opinion, it's not necessary, as IC 5532 has overdrive (shorting output) protection.
For LM324 , the same:
• Short Circuited Protected Outputs
OK. Now I built my split power supply, and it works! But, if I am not grounded, there is this annoying low buzz. When I am grounded (touching long wire, metal table, any large metal object, it is crystal clear. Any ideas?
Thanks for all the help so far! How I can spy of people!