Simplified pin definitions

include/spi.h

 
 #ifdef DEBUG
 
-// Arduino D2
-#define SCK_on PORTD |= PD2
-#define SCK_off PORTD &= ~(PD2)
-
-// Arduino D4
-#define MO_on PORTD |= PD4
-#define MO_off PORTD &= ~(PD4)
-
-// Arduino D7
-#define CS_on PORTD |= PD7
-#define CS_off PORTD &= ~(PD7)
-
-// Arduino D8
-#define MI_1 (PINB & PB0) == PB0
-#define MI_0 (PINB & PB0) != PB0
-
-// Arduino D12
-#define GDO_1 (PINB & PB4) == PB4
-#define GDO_0 (PINB & PB4) != PB4
+// Arduino D3 = PD3
+#define SCK_on PORTD |= PD3
+#define SCK_off PORTD &= ~(PD3)
+#define SCK_dir DDRD |= (1 << PD3)
+
+// Arduino D2 = PD2
+#define MO_on PORTD |= PD2
+#define MO_off PORTD &= ~(PD2)
+#define MO_dir DDRD &= ~(1 << PD2)
+
+// Arduino D8 = PB0
+#define CS_on PORTB |= PB0
+#define CS_off PORTB &= ~(PB0)
+#define CS_dir DDRB |= (1 << PB0)
+
+// Arduino D7 = PD7
+#define MI_1 (PIND & PD7) == PD7
+#define MI_0 (PIND & PD7) != PD7
+#define MI_dir DDRD |= (1 << PD7)
+
+// Arduino D9 = PB1
+#define GDO_1 (PINB & PB1) == PB1
+#define GDO_0 (PINB & PB1) != PB1
+#define GDO_dir DDRB &= ~(1 << PB1)
 
 #else
 
 #define SCK_on PORTB |= PB4
 #define SCK_off PORTB &= ~(PB4)
+#define SCK_dir DDRB |= (1 << PB4)
 
 #define MO_on PORTB |= PB3
 #define MO_off PORTB &= ~(PB3)
+#define MO_dir DDRB &= ~(1 << PB3)
 
 #define CS_on PORTB |= PB1
 #define CS_off PORTB &= ~(PB1)
+#define CS_dir DDRB |= (1 << PB1)
 
 #define MI_1 (PINB & PB2) == PB2
 #define MI_0 (PINB & PB2) != PB2
+#define MI_dir DDRB |= (1 << PB2)
 
 #define GDO_1 (PINB & PB0) == PB0
 #define GDO_0 (PINB & PB0) != PB0
+#define GDO_dir DDRB &= ~(1 << PB0)
 
 #endif
 

src/spi.c

 #include "spi.h"
 
 void spiInit(void) {
-#ifdef DEBUG
-    DDRB |= (1 << PB0);  // SI output
-    DDRD &= ~(1 << PD4); // SO input
-    DDRD |= (1 << PD2);  // SCLK output
-    DDRD |= (1 << PD7);  // CS output
-    DDRB &= ~(1 << PB4); // GDO0 input
-#else
-    DDRB |= (1 << PB2);  // SI output
-    DDRB &= ~(1 << PB3); // SO input
-    DDRB |= (1 << PB4);  // SCLK output
-    DDRB |= (1 << PB1);  // CS output
-    DDRB &= ~(1 << PB0); // GDO0 input
-#endif
+    MI_dir;
+    MO_dir;
+    SCK_dir;
+    CS_dir;
+    GDO_dir;
 
     SCK_off;
     MO_off;
 }
 
 void spiWrite(uint8_t command) {
-    SCK_off; //SCK start low
+    SCK_off;
     MO_off;
 
     uint8_t n = 8;