Let's Make Robots!

Add a speaker to the Start here robot

Hello everyone!  First off let me say that I am very very new to this and im learning. 

That being said I have a "Start here robot" that I built.  I have seen where other people have placed a small speaker on their projects to make beeps.  I would like to have that as well. But from what I have read on the Start here robot page I would have to move around, remove some chips and then put back in the darlington chip?  At this point im still making sense of the different chips and the project board so im sure this will be an easy for someone who has more experience than me.  I have  a small speaker from an old PC I had laying around. I just need to find a place hook it up.

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rik's picture

read node seventy five!

jscollett's picture

I looked at node 75 yesterday. I read some of the manual from picaxe.  I hooked up the positive wire from the speaker on pin 1 above my servo and hooked the negative wire above pin 7 where there are some grounds.  I was able to play some tunes at that point.  Do you think this could damage my robot? or do you think im ok?

rik's picture

on your speaker. A capacitor in series will prevent pin burn AND speaker burn. Regardles of type of speaker.

jscollett's picture

One thing that is different on my project is that im using "tune" instead of "sound" will this make a difference?  Also in the post you sent me Fritsl was talking about putting a low 1 command to turn off the speaker. would this help with mine as well?

bittybot's picture

as long as you have the 10 uf capacitor you should be good. Hmm mabe i will grab one of my 08m boards and make tutorial.

jscollett's picture

I think that the tutorial would rock.  It would really help people like me who has no experience with anything.  im learning but there are somethings I just don't know.

rik's picture

PC speaker are typically very low power, ordinary (electro magnetic) devices. They typically need some amplification to "drive" them from a picaxe.

Piezoelectric speakers do not need amplification. The tiny currents from the picaxe binary output are enough to produce a sound out of them. Make sure to put a 220 uF or bigger capacitor in series, between pin and piezo.

About the chips: your current set up (probably) has the resistor chip 330R in the DIL socket next to the binary outputs. Between that socket and the micro controller are some holes. You COULD solder some male header pins in there. This allows you to bypass the DIL socket. If you choose to do that, you must also choose which chip will sit in the socket: darlington OR resistor.

The resistor is needed only to protect the servo data line. You could do that with a single, ordinary 330 Ohm resistor. One will do fine. It will take some soldering.

The darlington is an amplifier. You do not need all the amplifiers that come with that chip. Again: one will do. You could replace it with your own amplification circuitry. But that will not be as easy as a single resistor in a data line.

I am not aware of any chip that would combine both functions (amp and resistor) in one DIL 16 package. But maybe a 8 pin darlington chip exists. You could combine it with a single resistor. Both could sit happily side by side in the DIL socket.