HOW TO – Servo as input device

Becky Stern

Becky Stern (sternlab.org is a DIY guru and director of wearable electronics at Adafruit. She publishes a new project video every week and hosts a live show on YouTube. Formerly Becky was Senior Video Producer for MAKE. Becky lives in Brooklyn, NY and belongs to art groups Free Art & Technology (“release early, often, and with rap music”) and Madagascar Institute (“fear is never boring”).

47 Articles

By Becky Stern

Becky Stern (sternlab.org is a DIY guru and director of wearable electronics at Adafruit. She publishes a new project video every week and hosts a live show on YouTube. Formerly Becky was Senior Video Producer for MAKE. Becky lives in Brooklyn, NY and belongs to art groups Free Art & Technology (“release early, often, and with rap music”) and Madagascar Institute (“fear is never boring”).

47 Articles

Matt Mets made this neat video about using a servo motor as an input device for keyframing a robot animation. He writes:

By reading the voltage from the center pin of the the servo’s potentiometer, it can be used as an input as well as an output device. Basically, you get a bunch of extra positional sensors ‘for free’. Some things that I could see this being useful for are:

1. Collision detection on unpowered arms (or even poor man’s torque detection by measuring the difference between what you requested and the actual position, assuming the servo doesn’t break).

2. Physical keyframing; you move the arms of the thing you are animating manually, then press a button to record that position, repeat a number of times and then have the computer play it back (see video)

3. Haptic feedback, if you can control the servo fast enough (doubtful, but worth a try).

Servo as input device for programing robot movements – Link.

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