* Feature: set_digits() for setting VFD digits

PT6302.c

@@ -58,6 +58,17 @@ void set_duty (uint8_t brightness)
     {
       brightness = 7;
     }
-  uint8_t command = 0x50 | brightness;
+  const uint8_t command = 0x50 | brightness;
+  transmit_bytes (&command, 1);
+}
+
+void set_digits (uint8_t digit_count)
+{
+  if (digit_count >= 16)
+    digit_count = 8; //we'll subtract 8 later from this number
+  if (digit_count < 9)
+    digit_count = 9;
+  digit_count -= 8;
+  const uint8_t command = 0x60 | digit_count;
   transmit_bytes (&command, 1);
 }

PT6302.h

@@ -37,6 +37,13 @@ void transmit_bytes (const uint8_t *payload, uint8_t size);
  * --------------------------------------------------------- */
 void set_ports (uint8_t gp1, uint8_t gp2);
 
+/* ---------------------------------------------------------------------------------------
+ * Sets the number of digit_count the VFD has
+ * digit_count below 9 are interpreted as 9 and digit_count above 16 are interpreted as 16
+ * Handles the entire communication
+ * --------------------------------------------------------------------------------------- */
+void set_digits(uint8_t digit_count);
+
 /* -----------------------------------------------------------
  * Sets duty cycle of controlled VFD
  * Brightness between 0 and 7 are accepted, any higher means 7

main.c

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