Karaoke Plays Music

I started with simple state machines last week. This week I want to talk about more complex state machines and interrupts. These are software topics but we’ll get back to the hardware soon.

The karaoke buttons that control music playback are far more complicated than either its disco button or the quadcopter’s power on sequence; if you press play on the karaoke, what happens? What if the door is open? What if there is no CD? What if it is already playing?

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Using Inputs and Outputs to Make a Toy

Having considered digital inputs and outputs, you’ve already seen more than 50% of a toy’s hardware. Oh sure, we should talk about the fancier sensors, motor control, and audio outputs but those are one-offs, specific to a toy’s particular function. Many toys don’t have them or only have one; buttons and lights are enough for some toys...

I’ve mentioned the processors in the toys a few times. I can’t show you what is inside the software (partially because the designers sensibly locked out the ability to read the code from their processors). I can show you how to figure out what is in the software without breaking any laws or copy protection.

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