Connect : Servo Motors

Wiring up a servo motor to your device is simple enough, but you can end up with lots of wires all over the place. The video above is fairly clear, we hope.

We’ll add some diagrams here when we get chance, but in the meantime here’s what you’ll need to do:

• The servo is the blue plastic thing – the ones we have helpfully have ‘servo motor’ printed on the side. You’ll find a strip of three wires coming out of it, ending in an odd little plug.
• Push short wires into each of the three holes in the servo’s plug. The colours of these wires don’t matter, but it’s often simplest to match the colours of the servo lead wires if you can: brown to black, red to red, orangey-yellow to yellow.
• You probably want to wrap a little bit of tape around these connections. It gets increasingly hard to find the one that’s fallen out.
• Next, you’ll need a crocodile-clip lead on each of the short wires. Again, it’s worth taping these up – partly the keep them secure, but also to stop the metal bits touching each other.
• OK, now to hook the other ends of the crocodile lead to the Kniwwelino:
  • Follow from the brown wire on the servo through to its loose crocodile clip. Clip that to the contact marked ‘GND‘ (‘ground’) on the Kniwwelino.
  • Follow along the servo’s red wire: clip that to ‘3.3V‘ on the Kniwwelino. The servo now has power – the 3.3V and GND contacts are like the + and – ends of a battery.
  • The last servo wire – the yellowish one – carries the control signal from the Kniwwelino. That goes to the contacts at the bottom of the Kniwwelino. For now, use the one labelled D5.

Your servo now has both power and control from the Kniwwelino. When a mood message arrives, it should spring into life and move.

That is, as long as the mood message is ‘Happy’ or ‘Sad’ – when we hand over the pile of bits, those are the only moods which are programmed. To respond to the rest of the moods (or to change what your device does with these two) you’ll need to start coding.

…and that’s our next little tutorial.