* QA: formatting

* Feature: `set_duty()` for setting VFD duty cycle

PT6302.c

@@ -42,7 +42,6 @@ void transmit_bytes (const uint8_t *payload, const uint8_t size)
   PORTB |= CSBpin;
 }
 
-
 void set_ports (uint8_t gp1, uint8_t gp2)
 {
   uint8_t command = 0x40;
@@ -52,3 +51,13 @@ void set_ports(uint8_t gp1, uint8_t gp2)
     command |= 0x02;
   transmit_bytes (&command, 1);
 }
+
+void set_duty (uint8_t brightness)
+{
+  if (brightness > 7)
+    {
+      brightness = 7;
+    }
+  uint8_t command = 0x50 | brightness;
+  transmit_bytes (&command, 1);
+}

PT6302.h

@@ -25,18 +25,24 @@ enum pins {
  * ------------------------------------------------------------- */
 void PT6302_startup (void);
 
-
 /* -------------------------------------------------------------------------------
  * Transmits size byte of data through the VFD controller's interface from payload
  * Handles CLKB, CSB and timing constraints
  * ------------------------------------------------------------------------------- */
 void transmit_bytes (const uint8_t *payload, uint8_t size);
 
-
 /* ---------------------------------------------------------
  * Sets GP1 and GP2 to the values given in the function call
  * Handles the entire communication
  * --------------------------------------------------------- */
 void set_ports (uint8_t gp1, uint8_t gp2);
 
+/* -----------------------------------------------------------
+ * Sets duty cycle of controlled VFD
+ * Brightness between 0 and 7 are accepted, any higher means 7
+ * duty = (brightness + 8)/16 (valid between 8/16 and 15/16)
+ * Handles the entire communication
+ * ----------------------------------------------------------- */
+void set_duty (uint8_t brightness);
+
 #endif //_PT6302_H_

main.c

@@ -12,6 +12,7 @@ int main ()
 {
   PT6302_startup ();
   set_ports (1, 1);
+  set_duty (7);
   while (1)
     {