initial stc rpn calculator project

src/utils.c

@@ -0,0 +1,47 @@
+#include <stdint.h>
+
+void _delay_ms(uint8_t ms)
+{
+    // delay function, tuned for 11.092 MHz clock
+    // optimized to assembler
+    ms; // keep compiler from complaining?
+    __asm;
+        ; dpl contains ms param value
+    delay$:
+        mov	b, #8   ; i
+    outer$:
+        mov	a, #243    ; j
+    inner$:
+        djnz acc, inner$
+        djnz b, outer$
+        djnz dpl, delay$
+    __endasm;
+}
+
+char* u32str(uint32_t x, char* buf, uint8_t base)
+{
+	int i = 0, j;
+	//corner case
+	if (x == 0){
+		buf[i] = '0';
+	}
+	//get reversed string
+	while(x > 0){
+		buf[i] = (x % base) + '0';
+		x /= base;
+		i++;
+	}
+	//add terminator
+	buf[i] = '\0';
+	i--; //back to last digit
+	//reverse string
+	for (j = 0; j < i; j++, i--){
+		char tmp;
+		tmp = buf[j];
+		buf[j] = buf[i];
+		buf[i] = tmp;
+	}
+
+	return buf;
+}
+