My twins just had a birthday and they received 6 of those cool birthday cards that play a greeting. I spent a good $40 bucks on the SpeakJet board,
but Hallmark somehow managed to do the same thing for $3 bucks, and squeeze it into a card? What’s in there?
There are a few different types of cards. They all play music and a greeting, but some have moving parts and some have LEDs. Here’s one of the basic cards that just plays music. There’s a little tab on the inside of the card that activates the circuit when the card is opened.
So what’s inside? I tore it open and it’s a tiny board with 3 x 1.5V coin cell batteries and a small speaker.
When I was designing the SpeakJet board, I ordered a few different sizes of speaker from Digi-Key in order to get a feel for what a 15mm vs a 20mm vs a 30mm speaker sounded like. I wanted to see how small I could go before it wasn’t loud enough.
This speaker is just like the one that I paid $1.80 for. Not bad.
The PCB is pretty cool too. You can’t reprogram them (I assume?), but at a minimum, I could cut the traces to the microcontroller and just use it as a 4.5V battery pack for a tiny project.
I torn the rest of them open and sourced a whole slew of goodies.
This one has a cool little motor attached. That might come in handy for something.
The speaker is the same exact one that SparkFun
sells for .95 cents.
I have two of this type. They have a little motor assembly that moves an arm back and forth. The arm was attached to a part of the card to make it jiggle. I don’t know what I’d use it for. Maybe I’ll just tear the motor out. We’ll see.
One has 2 small SMD LEDs.
A few of them have some contact switches.
At minimum, I sourced a ton of free batteries. This is just some of them. There were a few that were’t really designed to have the batteries torn out. They’re not soldered in, but the battery holder is crimped around the battery. I’d probably destroy it by taking a pair of pliers to it. I’m not ready to destroy them ….yet. So I’ll leave the batteries in those for now.
Free parts are always good!