servo module

Description

Uses the PWM controler of the ESP32 to drive a servo motor. Handles initialization, position control and speed limitation.

Settings

setting	type	default	range	description
pin	integer	26	> 0	number of the pin connected to the control input of the servo
frequency	integer	50	> 0	frequency (in $\text{Hz}$) of the PWM signal for the servo
channel	integer	3	(0, 15)	channel of the ESP32 pwm controller [1]
minDuty	integer	1000	≥ 0	minimum duty time (in µs) per PWM cycle
maxDuty	integer	2000	> 0	maximum duty time (in µs) per PWM cycle
minAngle	float	0.0	–	minimum of the range used to control the servo[2]
maxAngle	float	90.0	–	maximum of the range used to control the servo[2]
maxSpeed	float	0.0	≥ 0	maximum speed at which the motor moves from one position to the next[3]
initial	float	0.0	(minAngle, maxAngle)	position on the value range that the motor will drive to on initialization
infoLED	String	""	–	ID of an LED, module will attempt to send commands to the LED to indicate when changes have been made by a user[4]

1. ↑Some PWM channels might be in use by other hardware: Do not use channels 0 and 1 if a camera module is present on the same ESP32. When attaching more than one pin to a channel, both pins will deliver the same signal.
2. ↑The value range (minAngle,maxAngle) can be chosen freely and adjusted to suit the purpose. For example a symmetric 90° range (-45,45) or a percent range (0,100) can be used.
3. ↑Speed limit does not apply to first initialization, where the motor moves as fast as possible. Unit of measurement is that of the value range per second. Value of 0 means as fast as possible.
4. ↑Defaults to an empty String, in which case no attempts to operate the LED will be made.

Command Keys

key	type	range	description
move	integer	–	move the specified distance on the value range starting from the current position
moveTo	integer	(minAngle, maxAngle)	move to the specified position on the value range (absolute position)
binaryCtrl	boolean	–	move to minAngle if false and to maxAngle if true
hold	hold	–	keep motor powered after movement if true
identify	integer	> 0	highlight the hardware by its LED[4] for the specified time (in ms)

4. ↑ infoLED must be assigned, otherwise no LED will light up

Status

"controlId":"pinhole",
"status":
{
    "busy":false,
    "absolute":90,
    "relative":100
}

• busy – boolean, true if the motor is currently moving to a new position
• absolute – integer, current position of the motor on the value scale
• relative – float, current position of the motor as percentage of the total range

Events

• busy – occurs when the motor starts moving
• ready – occurs when the motor is done moving