User Manual

CircuitPython Servo

In order to use servos, we take advantage of pulseio . Now, in theory, you could just use the raw pulseio calls to set

the frequency to 50 Hz and then set the pulse widths. But we would rather make it a little more elegant and easy!

So, instead we will use adafruit_motor which manages servos for you quite nicely! adafruit_motor is a library so be

sure to grab it from the library bundle if you have not yet (https://adafru.it/zdx)! If you need help installing the library,

check out the CircuitPython Libraries page (https://adafru.it/ABU).

Servos come in two types:

A standard hobby servo - the horn moves 180 degrees (90 degrees in each direction from zero degrees).

A continuous servo - the horn moves 180 degrees like a DC motor. Instead of an angle specified, you set a

throttle value with 1.0 being full forward, 0.5 being half forward, 0 being stopped, and -1 being full reverse, with

other values between.

Servo Wiring

The connections for a servo are the same for standard servos and continuous rotation servos.

Connect the servo's brown or black ground wire to ground on the CircuitPython board.

Connect the servo's red power wire to 5V power, USB power is good for a servo or two. For more than that, you'll need

an external battery pack. Do not use 3.3V for powering a servo!

Connect the servo's yellow or white signal wire to the control/data pin, in this case A1 or A2 but you can use any PWM-

capable pin.

For example, to wire a servo to Trinket, connect the

ground wire to GND, the power wire to USB, and the

signal wire to 0.

Remember, A2 on Trinket is labeled "0".

Servos will only work on PWM-capable pins! Check your board details to verify which pins have PWM outputs.

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