Updated Drivers

drivers/0x04_pwm/0x04_pwm.c

@@ -44,22 +44,40 @@
 #define PWM_PIN     0
 #define PWM_FREQ_HZ 1000
 
+
+/**
+ * @brief Sweep the PWM duty cycle between start and end in given steps
+ *
+ * Iterates from start to end with the given step increment, updating
+ * the PWM duty cycle and printing each value with a 50 ms delay.
+ *
+ * @param start Starting duty percentage
+ * @param end   Ending duty percentage
+ * @param step  Increment per iteration (negative for descending)
+ */
+static void _sweep_duty(int start, int end, int step) {
+    for (int duty = start; (step > 0) ? duty <= end : duty >= end; duty += step) {
+        pwm_driver_set_duty_percent((uint8_t)duty);
+        printf("Duty: %3d%%\r\n", duty);
+        sleep_ms(50);
+    }
+}
+
+
+/**
+ * @brief Application entry point for the PWM LED breathing demo
+ *
+ * Initializes PWM at 1 kHz and sweeps the duty cycle up and down
+ * to produce a smooth LED breathing effect, reporting over UART.
+ *
+ * @return int Does not return
+ */
 int main(void) {
     stdio_init_all();
     pwm_driver_init(PWM_PIN, PWM_FREQ_HZ);
-
     printf("PWM driver initialized: GPIO%d @ %d Hz\r\n", PWM_PIN, PWM_FREQ_HZ);
-
     while (true) {
-        for (int duty = 0; duty <= 100; duty += 5) {
-            pwm_driver_set_duty_percent((uint8_t)duty);
-            printf("Duty: %3d%%\r\n", duty);
-            sleep_ms(50);
-        }
-        for (int duty = 100; duty >= 0; duty -= 5) {
-            pwm_driver_set_duty_percent((uint8_t)duty);
-            printf("Duty: %3d%%\r\n", duty);
-            sleep_ms(50);
-        }
+        _sweep_duty(0, 100, 5);
+        _sweep_duty(100, 0, -5);
     }
 }

drivers/0x04_pwm/pwm.c

@@ -36,6 +36,7 @@ static uint     pwm_slice;
 static uint     pwm_chan;
 static uint32_t pwm_wrap;
 
+
 /**
  * @brief Compute the PWM clock divider that yields the target frequency
  *
@@ -47,24 +48,38 @@ static uint32_t pwm_wrap;
  * @param wrap_val Chosen PWM counter wrap value (period - 1)
  * @return float   Clock divider to program into the PWM slice
  */
-static float calc_clk_div(uint32_t freq_hz, uint32_t wrap_val) {
+static float _calc_clk_div(uint32_t freq_hz, uint32_t wrap_val) {
     uint32_t sys_hz = clock_get_hz(clk_sys);
     return (float)sys_hz / ((float)freq_hz * (float)(wrap_val + 1));
 }
 
+
+/**
+ * @brief Apply the PWM configuration to the active slice
+ *
+ * Builds a default config, sets the clock divider for the target frequency,
+ * programs the wrap value, starts the slice, and zeroes the channel level.
+ *
+ * @param freq_hz Desired PWM output frequency in Hz
+ */
+static void _apply_pwm_config(uint32_t freq_hz) {
+    pwm_config cfg = pwm_get_default_config();
+    pwm_config_set_clkdiv(&cfg, _calc_clk_div(freq_hz, pwm_wrap));
+    pwm_config_set_wrap(&cfg, pwm_wrap);
+    pwm_init(pwm_slice, &cfg, true);
+    pwm_set_chan_level(pwm_slice, pwm_chan, 0);
+}
+
+
 void pwm_driver_init(uint32_t pin, uint32_t freq_hz) {
     gpio_set_function(pin, GPIO_FUNC_PWM);
     pwm_slice = pwm_gpio_to_slice_num(pin);
     pwm_chan  = pwm_gpio_to_channel(pin);
-    pwm_wrap  = 10000 - 1;  // resolution: 0.01% steps
-
-    pwm_config cfg = pwm_get_default_config();
-    pwm_config_set_clkdiv(&cfg, calc_clk_div(freq_hz, pwm_wrap));
-    pwm_config_set_wrap(&cfg, pwm_wrap);
-    pwm_init(pwm_slice, &cfg, true);
-    pwm_set_chan_level(pwm_slice, pwm_chan, 0);
+    pwm_wrap  = 10000 - 1;
+    _apply_pwm_config(freq_hz);
 }
 
+
 void pwm_driver_set_duty_percent(uint8_t percent) {
     if (percent > 100) {
         percent = 100;