update docs to indicate that SIPO works also for 595

lib/sipo_pwm.h

@@ -2,29 +2,34 @@
 
 // --- SIPO PWM Module ---
 //
-// SIPO = Serial IN, Parallel OUT
+// SIPO = shift register with paralel output.
 //
 // This module lets you use SIPO outputs as a "software PWM".
 //
-// Tested on 74HC4094,
-// should also work on 74HC595 (may need some small changes)
+// Tested to work on 74hc4094 and 74hc595
 
 #include <stdint.h>
 
 // Your file with configs
 #include "sipo_pwm_config.h"
 /*
-	// PWM pin aliases
+	// --- PWM pin aliases ---
+	
+	// Store signal
 	#define SPWM_STR  D2
+	// Shift/clock signal
 	#define SPWM_CLK  D3
+	// Data signal
 	#define SPWM_DATA D4
-
+	
+	// --- Other settings ---
+	
 	// Number of PWM levels (color depth)
 	#define SPWM_COLOR_DEPTH 256
-
+	
 	// Number of SIPO channels
 	#define SPWM_CHANNELS 24
-
+	
 	// Invert outputs (for Common Anode LEDs)
 	#define SPWM_INVERT 1
 */
@@ -38,7 +43,7 @@ extern uint8_t spwm_levels[SPWM_CHANNELS];
 void spwm_init();
 
 
-/** Display PWM channels.
- * This could be called in a Timer ISR.
+/** Perform one PWM cycle.
+ * This should be called in a Timer ISR or a loop.
  */
 void spwm_send();