CrazyVito11's Arduboy Clone

So i’ve finally completed my Arduboy clone! :grin:
Here it is, please forget the not-so-good-looking soldering job :sweat_smile:

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So i was just looking at the Arduboy library to see how it works when i noticed this:

#define PIN_SPEAKER_1 5 /< The pin number of the first lead of the speaker */
#define PIN_SPEAKER_2 13 /
< The pin number of the second lead of the speaker */

I connected the buzzer to pin 5 and GRN, but am i supposed to add another buzzer for the second audio channel (if that even exists)?

Connect the speaker between pins 5 and 13 instead of between 5 and GND.

No external parts required? Just directly connect it in between pin 5 and 13?
If that’s true i’ll go ahead and modify the connection tomorrow! :grin:

If its a piezo speaker, no extra parts required.

If it’s a regular voice coil speaker, you may need a current limiting resistor on one of the leads but you would need that for a connection to GND as well.

As far as i know i’ve used a buzzer.
What you see on the picture i’ve taken in the top right is a buzzer, right?

Can’t tell just from a picture. I’ve seen both types in that style. You need the specs or measure the resistance.

is it possible to find out is it is a speaker or a piezo just by looking at the power consumption of the entire unit? I know when my Arduboy clone is running consumes about 0.05A (or around 50mA).
I also know that each I/O can supply 20mA.
So i’m thinking if it is a voice coil speaker, the power consumption should increase by quite a bit since i am not using any resistors for the speaker/buzzer. :thinking:

And also if it was a voice coil speaker it should probably have hit the current limit of the I/O and then it should have been really quiet right? But the sound it produces is actually really loud.

@CrazyVito11 do you not have a link or something for the part you purchased?

Sadly i don’t have that. It was a buzzer i had lying around that came from a kit i purchased that was a Arduino UNO starter kit :confused:

If you can measure current, can you also measure resistance? If so, disconnect one of the speaker leads and measure the resistance of the speaker. If it’s close to infinite, it’s a piezo. If it’s around 8 - 32 ohms, it’s a speaker.

No, the opposite. The pin will try to drive the speaker with the maximum current it can supply, so the speaker will be loud.

Did the kit come with instructions on how to wire the buzzer?

Yes i can measure resistance, i have a multimeter that i can use. But i’ll first have to grab my soldering iron to disconnect the buzzer/speaker temporarily

I though it would become really quiet because a voltage drop would occur

No it wasn’t a kit like you assemble it and your done, no it was a kit that contained a lot of seperate parts for you to experiment with. Like a breadboard, sensors, buttons, displays and all that kind of stuff

Current is what causes loudness, not voltage.

Were any resistors included in the kit? If not, it’s probably a piezo. (Assuming that if it was a speaker, they would have included a 200 or so ohm resistor to safely wire it).

Yes there where, and i can be specific on the values they are. I got resistors that are 10K and resistors that are 1K

I should probably mention this, but i have 2 kinds of buzzers. I had 1 that had a board exposed at the bottom and i had 2 that had silicon at the bottom. So i measured both buzzers and this is what i measured:
The one that had a board exposed was 12 ohm, while the one with silicone was O.L. So i think it is safe to guess the one with silicone at the bottom is a buzzer.

Best to determine if it’s a speaker or piezo then.

If the volume is too loud for your liking, you can lower it with a resistor regardless of what type it is. However, if it’s a regular speaker, you may wish to put a capacitor in series as well as a resistor. Although well behaved sound generation code should always leave the pins low or at high impedance when not in use, bad code could leave one pin high and the other low, which would cause wasted current to flow.

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Sorry for asking so many questions btw :sweat_smile:

I’ll go ahead and measure that tomorrow.

Does this apply to both a speaker and a piezo?

The capacitor is only required for a speaker. A piezo is essentially a capacitor itself.

A low value resistor is required with a speaker to limit the current. A higher value resistor can be used with either to reduce the volume, if desired. I use a 10K resistor in series with the piezo on my breadboarded Arduino Micro based system just to reduce the volume.

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Okay, Thanks!
Tomorrow i’ll go ahead and measure the buzzer to really see if it is a piezo and i’ll modify the connections :slightly_smiling_face:

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So i just measured the piezo and found out that it was actually around 20M :sweat_smile:
I should just connect a 200 ohm resistor right? Oh and does it have to be connected to only one pin or to both pins?

20M is a strange value. It’s too high for a speaker and too low for a piezo. A piezo by itself should be unmeasurable, in the Gigaohm range. However, if it’s 20M you don’t need any resistor, just connect one lead directly to pin 5 and the other directly to pin 13.

If you find it too loud, you could try adding a 10K or so resistor (you may have to experiment with the exact value) between one of the pins and one speaker lead.

speaker

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