src: lib: Add set_pwm_channel_duty_cycle

src/lib.rs

@@ -469,6 +469,53 @@ impl Navigator {
         self.pwm.set_channel_off(channel.into(), value).unwrap();
     }
 
+    /// Sets the Duty Cycle (high value time) of selected channel.
+    ///
+    /// On PCA9685, this function sets the `OFF` counter and uses ON value as 0.
+    ///
+    /// # Further info
+    /// Check **[7.3.3 LED output and PWM control](https://www.nxp.com/docs/en/data-sheet/PCA9685.pdf#page=16)**
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use navigator_rs::{Navigator, PwmChannel};
+    ///
+    /// let mut nav = Navigator::new();
+    ///
+    /// nav.init();
+    /// nav.set_pwm_enable(true);
+    ///
+    /// nav.set_pwm_freq_prescale(99); // sets the pwm frequency to 60 Hz
+    /// nav.set_pwm_channel_duty_cycle(PwmChannel::Ch1, 50.0); // sets the duty cycle to 50%
+    /// ```
+    pub fn set_pwm_channel_duty_cycle(&mut self, channel: PwmChannel, duty_cycle: f32) {
+        let max_duty_cycle = 100.0;
+        let max_value = 4095;
+
+        if duty_cycle >= 100.0 {
+            if duty_cycle > 100.0 {
+                warn!(
+                    "Invalid duty cycle. Duty cycle must be less than or equal to 10, using 100."
+                );
+            };
+            self.pwm.set_channel_full_on(channel.into(), 0).unwrap();
+            return;
+        }
+
+        let duty_cycle = if duty_cycle < 0.0 {
+            warn!("Invalid duty cycle. Duty cycle must be non-negative, using 0.");
+            0.0
+        } else {
+            duty_cycle
+        };
+
+        let value = (duty_cycle / max_duty_cycle * max_value as f32) as u16;
+
+        self.pwm.set_channel_on(channel.into(), 0).unwrap();
+        self.pwm.set_channel_off(channel.into(), value).unwrap();
+    }
+
     /// Like [`set_pwm_channel_value`](struct.Navigator.html#method.set_pwm_channel_value). This function
     /// sets the Duty Cycle for a list of multiple channels.
     ///