SparkFun PiServoHat Initialise the qwiic_pca9685 python module at address with i2c_driver. More...

Inheritance diagram for pi_servo_hat.PiServoHat:

Public Member Functions
def	__init__ (self, address=None, debug=None, min_pt=1, max_pt=2)
	This method initializes the class object. More...

def	is_connected (self)
	Is an I2C connection established with the device? More...

def	restart (self)
	Soft resets the chip and then clears the MODE1 register to restart the PWM functionality. More...

def	get_pwm_frequency (self)
	Reads the PWM frequency used on outputs. More...

def	set_pwm_frequency (self, frequency=None)
	Configures the PWM frequency used on outputs. More...

def	get_pulse_time (self)
	Reads and returns the current min and max pulse times for servo movement. More...

def	set_pulse_time (self, min_pulse_time, max_pulse_time)
	Updates the minimum and maximum pulse widths for the servos. More...

def	move_servo_position (self, channel, position, swing=None)
	Moves servo to specified location in degrees. More...

def	set_duty_cycle (self, channel, duty_cycle)
	Moves servo to specified location based on duty-cycle. More...

def	get_servo_position (self, channel, swing=None)
	Reads the specified location for the servo in degrees. More...

def	sleep (self)
	Set the SLEEP bit to 1, which will unpower the servos. More...

def	wake (self)
	Set the SLEEP bit to 0, which will power the servos. More...

Public Attributes
	address

	debug

	PCA9685

	available_pwm_channels

	minimum_pulse_width

	maximum_pulse_width

Static Public Attributes
	device_name = _DEFAULT_NAME

	available_addresses = _AVAILABLE_I2C_ADDRESS

int	gcAddr = 0x00

int	acAddr = 0x70

int	subAddr_1 = 0x71

int	subAddr_2 = 0x72

int	subAddr_3 = 0x74

	frequency = _DEFAULT_SERVO_FREQUENCY

Detailed Description

SparkFun PiServoHat Initialise the qwiic_pca9685 python module at address with i2c_driver.

Parameters

address	The I2C address to use for the device. If not provided, the default address is used.
i2c_driver	An existing i2c driver object. If not provided a driver object is created.

Returns: Bool Constructor Initialization True- Successful False- Issue loading I2C driver

Constructor & Destructor Documentation

◆ init()

def pi_servo_hat.PiServoHat.__init__	(	self,
		address = `None`,
		debug = `None`,
		min_pt = `1`,
		max_pt = `2`
	)

This method initializes the class object.

If no 'address' or 'i2c_driver' are inputed or 'None' is specified, the method will use the defaults.

Parameters

address	The I2C address to use for the device. If not provided, the method will default to the first address in the 'available_addresses' list. Default = 0x40
debug	Designated whether or not to print debug statements. 0- Don't print debug statements 1- Print debug statements
min_pt	The minimum pulse time of the servos in milliseconds. If not provided, default to 1 ms
max_pt	The maximum pulse time of the servos in milliseconds. If not provided, default to 2 ms

Member Function Documentation

◆ get_pulse_time()

def pi_servo_hat.PiServoHat.get_pulse_time ( self )

Reads and returns the current min and max pulse times for servo movement.

Returns: tuple: The minimum and maximum pulse times in milliseconds

◆ get_pwm_frequency()

def pi_servo_hat.PiServoHat.get_pwm_frequency ( self )

Reads the PWM frequency used on outputs.

50 Hz is recommended for most servos.

Returns: Integer PWM Frequency Range: 24 Hz to 1526 Hz

◆ get_servo_position()

def pi_servo_hat.PiServoHat.get_servo_position	(	self,
		channel,
		swing = `None`
	)

Reads the specified location for the servo in degrees.

Parameters

channel	Channel of Servo to Control Range: 0 to 15
swing	Range of Servo Movement 90- 90 Degree Servo 180- 180 Degree Servo

Returns: Float Esitmated Position (Degrees)

◆ is_connected()

def pi_servo_hat.PiServoHat.is_connected ( self )

Is an I2C connection established with the device?

Returns: Bool Device Connection Status True- Connected False- Not Connected

◆ move_servo_position()

def pi_servo_hat.PiServoHat.move_servo_position	(	self,
		channel,
		position,
		swing = `None`
	)

Moves servo to specified location in degrees.

Parameters

channel	Channel of Servo to Control Range: 0 to 15
position	Position (Degrees) Range: Open, but should between 0 and specified servo 'swing'. The range is not regulated because most servos have extra room for play (i.e. a 90 degree servo may have a +120 degree usable swing). If 'None' is specified, the default setting is 90 degrees.
swing	Range of Servo Movement 90- 90 Degree Servo 180- 180 Degree Servo

◆ restart()

def pi_servo_hat.PiServoHat.restart ( self )

Soft resets the chip and then clears the MODE1 register to restart the PWM functionality.

The PWM frequency is returned to the default 50 Hz setting.

◆ set_duty_cycle()

def pi_servo_hat.PiServoHat.set_duty_cycle	(	self,
		channel,
		duty_cycle
	)

Moves servo to specified location based on duty-cycle.

Parameters

channel	Channel of Servo to Control Range: 0 to 15
duty_cycle	Duty-Cycle (Percentage) Float Range: 0 to 100 (%) Resolution: 1/4096

◆ set_pulse_time()

def pi_servo_hat.PiServoHat.set_pulse_time	(	self,
		min_pulse_time,
		max_pulse_time
	)

Updates the minimum and maximum pulse widths for the servos.

Args: min_pulse_time (float): The new minimum pulse width in ms max_pulse_time (float): The new maximum pulse width in ms

Returns: bool: Returns true if update was successful, false if an error was encountered

◆ set_pwm_frequency()

def pi_servo_hat.PiServoHat.set_pwm_frequency	(	self,
		frequency = `None`
	)

Configures the PWM frequency used on outputs.

50 Hz is the default and recommended for most servos.

Parameters

frequency PWM Frequency Range: 24 Hz to 1526 Hz

Returns: Bool Function Operation True- Successful False- Issue in Execution

NOTE: Changing PWM frequency affects timing for servo positioning. Additionally, the servo position needs to be reset for the output control (on all channels). The output on all channels is initially turned off after the frequency change, but is re-enabled after any of the channels is reconfigured. However, the new PWM frequency will be in affect, so the timing of the outputs on the other channels will be off. (i.e. if a PWM frequency is doubled; the timing of that signal may be halfed.)

◆ sleep()

def pi_servo_hat.PiServoHat.sleep ( self )

Set the SLEEP bit to 1, which will unpower the servos.

This preserves the life of the servos.

◆ wake()

def pi_servo_hat.PiServoHat.wake ( self )

Set the SLEEP bit to 0, which will power the servos.

Member Data Documentation

◆ acAddr

int pi_servo_hat.PiServoHat.acAddr = 0x70

static

◆ address

pi_servo_hat.PiServoHat.address

◆ available_addresses

pi_servo_hat.PiServoHat.available_addresses = _AVAILABLE_I2C_ADDRESS

static

◆ available_pwm_channels

pi_servo_hat.PiServoHat.available_pwm_channels

◆ debug

pi_servo_hat.PiServoHat.debug

◆ device_name

pi_servo_hat.PiServoHat.device_name = _DEFAULT_NAME

static

◆ frequency

pi_servo_hat.PiServoHat.frequency = _DEFAULT_SERVO_FREQUENCY

static

◆ gcAddr

int pi_servo_hat.PiServoHat.gcAddr = 0x00

static

◆ maximum_pulse_width

pi_servo_hat.PiServoHat.maximum_pulse_width

◆ minimum_pulse_width

pi_servo_hat.PiServoHat.minimum_pulse_width

◆ PCA9685

pi_servo_hat.PiServoHat.PCA9685

◆ subAddr_1

int pi_servo_hat.PiServoHat.subAddr_1 = 0x71

static

◆ subAddr_2

int pi_servo_hat.PiServoHat.subAddr_2 = 0x72

static

◆ subAddr_3

int pi_servo_hat.PiServoHat.subAddr_3 = 0x74

static

The documentation for this class was generated from the following file:

pi_servo_hat.py

Public Member Functions

Public Attributes

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ __init__()

Member Function Documentation

◆ get_pulse_time()

◆ get_pwm_frequency()

◆ get_servo_position()

◆ is_connected()

◆ move_servo_position()

◆ restart()

◆ set_duty_cycle()

◆ set_pulse_time()

◆ set_pwm_frequency()

◆ sleep()

◆ wake()

Member Data Documentation

◆ acAddr

◆ address

◆ available_addresses

◆ available_pwm_channels

◆ debug

◆ device_name

◆ frequency

◆ gcAddr

◆ maximum_pulse_width

◆ minimum_pulse_width

◆ PCA9685

◆ subAddr_1

◆ subAddr_2

◆ subAddr_3

◆ init()