Is there a way to output the synthesized sound to a speaker?

[DIBYAYAN MANDAL]

I want to play the synthesized sound directly on the speaker (8 ohm ones) connected to arduino pwm pins. Is it possible?

[tomco...@live.fr]

Hi!

Straight from an Arduino that might be problematic: as per https://electronics.stackexchange.com/questions/67092/how-much-current-can-i-draw-from-the-arduinos-pins one can draw around 40mA on a pin. Now, outputting a signal of maximum 5V into 8ohm leads to (roughly, not taking AC nature of the signal into play) 5/8=0.625A = 625mA so more than 15 times to much. The pin won't resist which could lead to it no drawing the current (if the pin is protected, I am never sure of that) in the best case to the Arduino frying as a whole.

This can be achieved quite easily by plugging a small audio amplifier, there are small modules like that available on the net.

Hope this helps,

[Steve R]

An 8 ohm speaker doesn't behave like an 8 ohm resistor - it's an inductive load so has an even lower impedance at low frequencies.  

If the current doesn't kill the Arduino, the back-EMF probably will.  If you stick a pulse of current into a speaker, when the pulse ends (as it would with PWM) the speaker will try to keep that current flowing, and it will generate a negative voltage, which is very likely to damage the Arduino output pin and possibly do further damage.  Same thing happens if you connect a relay directly to an Arduino. 

Plenty of small cheap amplifiers on ebay.   That's the only sensible option.

Steve

[max powe]

I tried it and it didn't fry mi arduino, but the sound was mild. In order to amplify it I arranged a basic amplifier using a Tip31C and a 320 Resitor

[tomco...@live.fr]

Nice! I am always amazed how these things resist!

If that sounds good would you mind sharing the schematic? Sounds like some other people would also be interested in.

Best,