adafruit_motor.motor
¶
Simple control of a DC motor. DC motors have two wires and should not be connected directly to the PWM connections. Instead use intermediate circuitry to control a much stronger power source with the PWM. The Adafruit Stepper + DC Motor FeatherWing, Adafruit TB6612 1.2A DC/Stepper Motor Driver Breakout Board and Adafruit Motor/Stepper/Servo Shield for Arduino v2 Kit - v2.3 do this for popular form factors already.
Note
The TB6612 boards feature three inputs XIN1, XIN2 and PWMX. Since we PWM the INs directly its expected that the PWM pin is consistently high.
- Author(s): Scott Shawcroft
-
class
adafruit_motor.motor.
DCMotor
(positive_pwm, negative_pwm)[source]¶ DC motor driver.
positive_pwm
andnegative_pwm
can be swapped if the motor runs in the opposite direction from what was expected for “forwards”.Parameters: -
throttle
¶ Motor speed, ranging from -1.0 (full speed reverse) to 1.0 (full speed forward), or
None
. IfNone
, both PWMs are turned full off. If0.0
, both PWMs are turned full on.
-
adafruit_motor.servo
¶
Servos are motor based actuators that incorporate a feedback loop into the design. These feedback loops enable pulse width modulated control to determine position or rotational speed.
- Author(s): Scott Shawcroft
-
class
adafruit_motor.servo.
ContinuousServo
(pwm_out, *, min_pulse=750, max_pulse=2250)[source]¶ Control a continuous rotation servo.
Parameters: -
throttle
¶ How much power is being delivered to the motor. Values range from
-1.0
(full throttle reverse) to1.0
(full throttle forwards.)0
will stop the motor from spinning.
-
-
class
adafruit_motor.servo.
Servo
(pwm_out, *, actuation_range=180, min_pulse=750, max_pulse=2250)[source]¶ Control the position of a servo.
Parameters: - pwm_out (PWMOut) – PWM output object.
- actuation_range (int) – The physical range of motion of the servo in degrees, for the given
min_pulse
andmax_pulse
values. - min_pulse (int) – The minimum pulse width of the servo in microseconds.
- max_pulse (int) – The maximum pulse width of the servo in microseconds.
actuation_range
is an exposed property and can be changed at any time:servo = Servo(pwm) servo.actuation_range = 135
The specified pulse width range of a servo has historically been 1000-2000us, for a 90 degree range of motion. But nearly all modern servos have a 170-180 degree range, and the pulse widths can go well out of the range to achieve this extended motion. The default values here of
750
and2250
typically give 135 degrees of motion. You can setactuation_range
to correspond to the actual range of motion you observe with your givenmin_pulse
andmax_pulse
values.Warning
You can extend the pulse width above and below these limits to get a wider range of movement. But if you go too low or too high, the servo mechanism may hit the end stops, buzz, and draw extra current as it stalls. Test carefully to find the safe minimum and maximum.
-
actuation_range
¶ The physical range of motion of the servo in degrees.
-
angle
¶ The servo angle in degrees. Must be in the range
0
toactuation_range
.