Step 12: Transferring the circuitry from the Arduino test-bed to the final in-situ wiring
This was a varying mess of cables, and occasionally defunct parts of the earlier versions of the circuit were still left in the breadboard.
For example LEDs were used to visually indicate when a potentiometer had been moved in one version, but this was for testing only so did not need to be transferred to the final housing
The first thing to do was to try to work out how the cables might fit in the box housing.
The final potentiometers were put in first, and then the circuit tested with these in place, with the rest of the circuit still on the breadboard. This was to check that the potentiometers and their connections had not been damaged during installation .
A schematic wiring drawing was made to indicate where the wires would best fit into the box.
This was a reference guide to to follow during the physical installation which made it pretty easy.
The potentiometers went in first (above, left) , followed by the Arduino board, and the additional transistor circuit (above, right)
Most of the circuit components needed to be connected up between the earth and 5V power rails. This included the power/earth connections to the Arduino, the control potentiometers, the 2 servos and the LED/transistor circuit.
This was done by simply soldering all the power connections together a small offcut of circuit board (right) and all the earth connections on another (left)
The wiring for the housing was all done using 1mm garden trellis wire. This can be bought at a garden shop and is much cheaper than buying from an electronics supplier.
It has the additional advantage of retaining it's shape when bent. This is because it has a single wire core, not a stranded core like most electronics wire.
This makes it great for staying neat in the box and doesn't require cable ties as it is quite rigid.
The ends of the connections were then connected via the conduit hole in the base of the head to a connection block to allow easy connection to the face control mechanism later.
On the left is the finished head with the box open to expose the Arduino circuitry in the base.
On the right is the finished head with the face removed to show the flexible connections from the face mechanisms to the connection block in the base of the head.