Add empty floppicator project

src/utility.c

@@ -0,0 +1,65 @@
+#include "utility.h"
+
+#include "mem_registers.h"
+#include "monitor_subroutines.h"
+#include "line_data.h"
+
+void num_to_decbuf(uint16_t n, uint8_t len, uint8_t *buf) {
+	
+	for(uint8_t idx = 0; idx < len; idx++) {
+		buf[idx] = n % 10;
+		n /= 10;
+	}
+}
+
+// https://stackoverflow.com/questions/2602823/in-c-c-whats-the-simplest-way-to-reverse-the-order-of-bits-in-a-byte
+uint8_t bit_reverse(uint8_t b) {
+	b = (b & 0xF0) >> 4 | (b & 0x0F) << 4;
+	b = (b & 0xCC) >> 2 | (b & 0x33) << 2;
+	b = (b & 0xAA) >> 1 | (b & 0x55) << 1;
+	
+	return b;
+}
+
+// https://stackoverflow.com/questions/14009765/fastest-way-to-count-bits
+uint8_t bit_count(uint8_t b) {
+    b = (b & 0x55) + (b >> 1 & 0x55);
+    b = (b & 0x33) + (b >> 2 & 0x33);
+    b = (b & 0x0f) + (b >> 4 & 0x0f);
+	
+	return b;
+}
+
+void lfsr_init(uint16_t reg) {
+	*((uint16_t*)LFSR_REGISTER_ADDRESS) = 0xF00D;
+}
+
+uint16_t lfsr_update(void) {
+	uint16_t *lfsr = ((uint16_t*)LFSR_REGISTER_ADDRESS);
+
+	*lfsr ^= (*lfsr) >> 7;
+	*lfsr ^= (*lfsr) << 9;
+	*lfsr ^= (*lfsr) >> 13;
+
+    return *lfsr;
+}
+
+#define CRC8RDALLAS_POLY 0x31
+uint8_t calculate_crc8(uint8_t* data, uint8_t len) {
+	uint8_t crc = 0;
+	
+	for(uint8_t data_idx = 0; data_idx < len; data_idx++) {
+		uint8_t carry;
+		uint8_t d = data[data_idx]; 
+		
+		for (uint8_t i = 8; i > 0; i--) {
+			carry = (crc & 0x80);
+			crc <<= 1;
+			if (d & 1) crc |= 1;
+			d >>= 1;
+			if (carry) crc ^= CRC8RDALLAS_POLY;		
+		}	
+	}
+		
+	return crc;
+}