new PWMOutputDevice(pin, active_high, initial_value, frequency)
- Source:
Generic output device configured for pulse-width modulation (PWM).
Parameters:
| Name | Type | Description |
|---|---|---|
pin |
int | Pin | The GPIO pin which the device is attached to. |
active_high |
boolean | If ``true`` (the default), the on method will set the GPIO to HIGH. If ``false``, the on method will set the GPIO to LOW (the off method always does the opposite). |
initial_value |
int | If ``0`` (the default), the device's duty cycle will be 0 initially. Other values between 0 and 1 can be specified as an initial duty cycle. Note that ``undefined`` cannot be specified (unlike the parent class) as there is no way to tell PWM not to alter the state of the pin. |
frequency |
int | The frequency (in Hz) of pulses emitted to drive the device. Defaults to 100Hz. |
Throws:
OutputDeviceBadValue - When intial_value is ``undefined``.
Methods
blink(on_timeopt, off_timeopt, fade_in_timeopt, fade_out_timeopt, nopt, {@callback})
Make the device turn on and off repeatedly.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
on_time |
float |
<optional> |
Number of seconds on. Defaults to 1 second. |
off_time |
float |
<optional> |
Number of seconds off. Defaults to 1 second. |
fade_in_time |
float |
<optional> |
Number of seconds to spend fading in. Defaults to 0. |
fade_out_time |
float |
<optional> |
Number of seconds to spend fading out. Defaults to 0. |
n |
int |
<optional> |
Number of times to blink; ``undefined`` (the default) means forever. |
{@callback} |
[callback] - Function to be called after n loops. |
close()
Stop any actions such as blink and unlink from pin.
frequency(valueopt) → {int}
- Source:
Sets or Gets the device frequency.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
value |
int |
<optional> |
The new frequency for the device. |
Returns:
- If value is undefined then the current device frequency is returned.
- Type
- int
is_active() → {boolean}
Returns:
- If the device has a value other than 0 then true.
- Type
- boolean
off()
Turn the device off.
on()
Turn the device fully on.
pulse(fade_in_timeopt, fade_out_timeopt, nopt, {@callback})
Make the device fade in and out repeatedly.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
fade_in_time |
float |
<optional> |
Number of seconds to spend fading in. Defaults to 0. |
fade_out_time |
float |
<optional> |
Number of seconds to spend fading out. Defaults to 0. |
n |
int |
<optional> |
Number of times to blink; ``undefined`` (the default) means forever. |
{@callback} |
[callback] - Function to be called after n loops. |
toggle()
Toggle the state of the device. If the device is currently off (value` is 0.0),
this changes it to "fully" on (`value` is 1.0).
If the device has a duty cycle (`value`) of 0.1, this will toggle it to 0.9, and so on.
value(valueopt) → {float}
- Source:
The duty cycle of the PWM device. 0.0 is off, 1.0 is fully on.
Values in between may be specified for varying levels of power in the device.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
value |
float |
<optional> |
When defined then sets the device duty cycle. |
Returns:
- When value is undefined then the current duty cycle is returned.
- Type
- float