update header

extras/pwm/pwm.h

@@ -16,14 +16,41 @@
 extern "C" {
 #endif
 
-//Warning: Printf disturb pwm, use uart_putc instead.
+//Warning: Printf disturb pwm. You can use "uart_putc" instead.
 
+/**
+ * Initialize pwm
+ * @param npins Number of pwm pin used
+ * @param pins Array pointer to the pins
+ * @param reverse If true, the pwm work in reverse mode
+ */    
 void pwm_init(uint8_t npins, const uint8_t* pins, uint8_t reverse);
+
+/**
+ * Set PWM frequency. If error, frequency not set
+ * @param freq PWM frequency value in Hertz
+ */  
 void pwm_set_freq(uint16_t freq);
+
+/**
+ * Set Duty between 0 and UINT16_MAX
+ * @param duty Duty value
+ */  
 void pwm_set_duty(uint16_t duty);
 
+/**
+ * Restart the pwm signal
+ */  
 void pwm_restart();
+
+/**
+ * Start the pwm signal
+ */  
 void pwm_start();
+
+/**
+ * Stop the pwm signal
+ */  
 void pwm_stop();
 
 #ifdef __cplusplus