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Step 4Electronics- flex sensors and lights
The flex sensors are soldered in to a simple volage divider circuit to provide a variable input voltage to the MAKE controller's analog inputs.
You can play around with different resistor values but the voltage to be input to the controller should not exceed 3.3V
Cut three equal lengths of 22ga wire- one red, one black and another color for the signal wire. Solder them to the flex sensor as shown on the diagram. Generally speaking, the shorter you can keep the wires the better- flex sensors tend to lose resolution and get "noisy" as the lead wires get longer. I was able to make the wires long enough to reach all the way to my hand and still get good results.
I put heat shrink tubing over my soldered connections and I glued some flexible rubber tubing onto a glove and slid the sensors into the tubing. It is important to note that the sensors only work when bent in one direction- the printed side of the sensor goes on the outside of the bend.
While I used a glove for my test rig, the finished costume will have the sensors mounted on my elbows to keep them hidden.
The lights for the eyes are just a couple of super bright 2.4v 5000mcd red LED's (Radio Shack part#276-086) that are hot glued into a couple of old halogen lamp reflectors that had the bulbs removed. The LED's are wired in series with a momentary switch that is activated when the head drops all the way down. The power for the LED's comes directly from the 5v output on the MAKE controller board. I left the wires for the lights extra long so it would be easier to mount them in the finished head and the lamp housings are held onto the brass plate with some hot glue and zip ties.
You can play around with different resistor values but the voltage to be input to the controller should not exceed 3.3V
Cut three equal lengths of 22ga wire- one red, one black and another color for the signal wire. Solder them to the flex sensor as shown on the diagram. Generally speaking, the shorter you can keep the wires the better- flex sensors tend to lose resolution and get "noisy" as the lead wires get longer. I was able to make the wires long enough to reach all the way to my hand and still get good results.
I put heat shrink tubing over my soldered connections and I glued some flexible rubber tubing onto a glove and slid the sensors into the tubing. It is important to note that the sensors only work when bent in one direction- the printed side of the sensor goes on the outside of the bend.
While I used a glove for my test rig, the finished costume will have the sensors mounted on my elbows to keep them hidden.
The lights for the eyes are just a couple of super bright 2.4v 5000mcd red LED's (Radio Shack part#276-086) that are hot glued into a couple of old halogen lamp reflectors that had the bulbs removed. The LED's are wired in series with a momentary switch that is activated when the head drops all the way down. The power for the LED's comes directly from the 5v output on the MAKE controller board. I left the wires for the lights extra long so it would be easier to mount them in the finished head and the lamp housings are held onto the brass plate with some hot glue and zip ties.
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I am almost finished writing all the code for my Arduino animatronics tutorial and I've designed a board that will allow you to connect six bend sensors to six servos (amongst other things) so stay tuned!