added facility to debug the stack pointer on P3_4 (LCD LED cathode)

roughly 139 bytes
functions were chosen by manually traversing pow_decn to the bottom

src/utils.h

@@ -35,9 +35,6 @@ void _delay_us(uint8_t us);
 #define _delay_us(x) _delay_ms(1)
 #endif
 
-void backlight_off(void);
-
-
 
 #ifdef __linux__
 #define DESKTOP
@@ -58,11 +55,9 @@ char* u32str(uint32_t x, char* buf, uint8_t base);
 #define __at uint8_t*
 #define SDCC_ISR(isr, reg)
 #define __using(x)
-#define BACKLIGHT_ON()
 #define TURN_OFF()
 #else
 #define SDCC_ISR(isr, reg) __interrupt (isr) __using (reg)
-#define BACKLIGHT_ON()  P3_4 = 0
 #define TURN_OFF() P3_2 = 0
 #endif