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LEDC PWM

The ledc_pwm module provides abstractions and state management around the low-level ledc API provided by AtomVM, and helps to mitigate common errors with use of the low-level APIs.

The API is more "object-oriented", in that it separates the notion of a timer and channel into separate referencible entities, making it easier to manage the lifecycle of these objects.

Furthermore, the high-level API manages the relationship between a frequency set on a timer, the duty cycle resolution defined by that frequency, and the duty cycle, as set by the user. As the details between this values is hidden, the user can set a frequency for a timer, and then specify the duty cycle as a percentage (a value between 0 and 100, inclusive), so that he or she does not need to manually compute which duty cycles are appropriate for which frequency, as one needs to do in the low-level API.

Programming Manual

TODO

Sample Code

The following code illustrates use of the high-level API:

%% create a 5khz timer
Freq = 5000.
{ok, Timer} = ledc_pwm:create_timer(Freq).

%% bind pin 2 to this timer in a channel
Pin = 2.
{ok, Channel} = ledc_pwm:create_channel(Timer, Pin).

io:format("Frequency(hz): ~p Duty(%): ~p~n", [ledc_pwm:get_freq_hz(Channel), ledc_pwm:get_dutyp(Channel)]).

%% set the duty cycle to 0%, and fade up to 100% over 5 seconds
TargetDutyp = 100.
FadeMs = 5000.
ledc_pwm:set_dutyp(Channel, 0).
ledc_pwm:fade(Channel, TargetDutyp, FadeMs).

LEDC PWM Example

The LEDC PWM example program illustrates use of the LEDC PWM API. See the README for information about how to build, flash, and run this exmaple program.