diff --git a/firmware/scripts/wspr_coding b/firmware/scripts/wspr_coding
deleted file mode 100755
index ed8466e..0000000
Binary files a/firmware/scripts/wspr_coding and /dev/null differ
diff --git a/firmware/scripts/wspr_coding.c b/firmware/scripts/wspr_coding.c
index 4317e95..b23efca 100644
--- a/firmware/scripts/wspr_coding.c
+++ b/firmware/scripts/wspr_coding.c
@@ -3,6 +3,8 @@
 #include <stdint.h>
 #include <string.h>
 
+static const uint8_t WSPR_LENGTH = 162;
+
 uint8_t wspr_call_char(char c) {
 	c = toupper(c);
 	if(c >= '0' && c <= '9') {
@@ -41,18 +43,18 @@ uint8_t wspr_power(uint8_t power) {
 uint64_t wspr_message(char *call, char *loc, uint8_t power) {
 	uint32_t m, n;
 
-	n = wspr_loc_char(call[0]);
-	n = n * 36 + wspr_loc_char(call[1]);
-	n = n * 10 + wspr_loc_char(call[2]);
-	n = n * 27 + wspr_loc_char(call[3]) - 10;
-	n = n * 27 + wspr_loc_char(call[4]) - 10;
-	n = n * 27 + wspr_loc_char(call[5]) - 10;
+	n = wspr_call_char(call[0]);
+	n = n * 36 + wspr_call_char(call[1]);
+	n = n * 10 + wspr_call_char(call[2]);
+	n = n * 27 + wspr_call_char(call[3]) - 10;
+	n = n * 27 + wspr_call_char(call[4]) - 10;
+	n = n * 27 + wspr_call_char(call[5]) - 10;
 
 	m = 179 - 10 * wspr_loc_char(loc[0]) - wspr_loc_char(loc[2]);
 	m = m * 180 + 10 * wspr_loc_char(loc[1]) + wspr_loc_char(loc[3]);
 	m = m * 128 + wspr_power(power) + 64;
 
-	return n << 21 | m;
+	return ((uint64_t) n) << 22 | m;
 }
 
 const uint32_t WSPR_FEC_TAPS1 = 0xF2D05351;
@@ -68,13 +70,13 @@ uint8_t wspr_parity32(uint32_t x) {
 }
 
 void wspr_fec(uint64_t msg, uint8_t *output) {
-	memset(output, 0, 162);
+	memset(output, 0, WSPR_LENGTH);
 
 	uint32_t reg = 0;
 	for(uint8_t i = 0;  i < 81; i++) {
 		uint8_t bit = 0;
 		if(i < 50) {
-			bit = (msg & (1 << (50 - i))) != 0;
+			bit = (msg >> (50 - i - 1)) & 1;
 		}
 
 		reg = (reg << 1) | bit;
@@ -104,9 +106,9 @@ uint8_t wspr_reverse_bits(uint8_t bits) {
 void wspr_interleave(uint8_t *input, uint8_t *output) {
 	uint8_t p = 0;
 	uint8_t i = 0;
-	while(p < 162) {
+	while(p < WSPR_LENGTH) {
 		uint8_t rev_i = wspr_reverse_bits(i);
-		if(rev_i < 162) {
+		if(rev_i < WSPR_LENGTH) {
 			output[rev_i] = input[p];
 			p++;
 		}
@@ -122,23 +124,65 @@ const uint8_t WSPR_SYNC[162] = {
 };
 
 void wspr_add_sync(uint8_t *symbols) {
-	for(uint8_t i = 0; i < 161; i++) {
+	for(uint8_t i = 0; i < WSPR_LENGTH; i++) {
 		symbols[i] = WSPR_SYNC[i] + 2 * symbols[i];
 	}
 }
 
-int main(int argc, char const *argv[]) {
+uint64_t validation_msg = 1086526031934565;
+
+uint8_t validation_bits[162] = {
+	1,1,1,0,1,1,1,1,1,0,0,0,1,1,1,0,0,1,0,0,1,1,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,1,1,0,0,0,
+	1,1,0,1,1,0,1,1,0,0,0,1,1,1,1,1,1,0,0,1,1,1,1,1,1,1,1,0,1,1,1,0,1,0,1,0,1,1,0,1,0,1,0,1,
+	0,0,0,1,0,0,0,1,0,1,1,1,1,0,0,0,0,0,0,1,1,1,1,1,1,1,0,1,1,0,1,0,1,0,0,0,1,1,0,0,1,1,1,1,
+	0,1,1,0,1,1,0,1,0,1,0,1,0,1,0,1,1,0,0,0,1,1,0,1,0,0,1,1,1,1
+};
+
+uint8_t validation[162] = {
+	3, 3, 0, 0, 2, 0, 0, 0, 1, 0, 2, 0, 1, 3, 1, 2, 2, 2, 1, 0, 0, 3, 2, 3, 1, 3, 3, 2, 2, 0,
+	2, 0, 0, 0, 3, 2, 0, 1, 2, 3, 2, 2, 0, 0, 2, 2, 3, 2, 1, 1, 0, 2, 3, 3, 2, 1, 0, 2, 2, 1,
+	3, 2, 1, 2, 2, 2, 0, 3, 3, 0, 3, 0, 3, 0, 1, 2, 1, 0, 2, 1, 2, 0, 3, 2, 1, 3, 2, 0, 0, 3,
+	3, 2, 3, 0, 3, 2, 2, 0, 3, 0, 2, 0, 2, 0, 1, 0, 2, 3, 0, 2, 1, 1, 1, 2, 3, 3, 0, 2, 3, 1,
+	2, 1, 2, 2, 2, 1, 3, 3, 2, 0, 0, 0, 0, 1, 0, 3, 2, 0, 1, 3, 2, 2, 2, 2, 2, 0, 2, 3, 3, 2,
+	3, 2, 3, 3, 2, 0, 0, 3, 1, 2, 2, 2
+};
+
+int main(int argc, char const *argv[]) {
+	uint8_t test[162];
+	uint8_t test1[162];
+	uint64_t msg = wspr_message(" K1ABC", "FN42", 37);
+
+
+	if(msg == validation_msg) {
+		printf("%lu✓\n", msg);
+	}
+	else {
+		printf("%lu✗\n", msg);
+	}
 
-	uint8_t test[161];
-	uint8_t test1[161];
-	uint64_t msg = wspr_message("DL1SSK", "JN39WE", 27);
 
 	wspr_fec(msg, test);
+
+	for(uint8_t i = 0; i < WSPR_LENGTH; i++) {
+		if(test[i] == validation_bits[i]) {
+			printf("%d✓", test[i]);
+		}
+		else {
+			printf("%d✗", test[i]);
+		}
+	}
+	printf("\n\n");
+
 	wspr_interleave(test, test1);
 	wspr_add_sync(test1);
 
-	for(uint8_t i = 0; i < 161; i++) {
-		printf("%d,", test1[i]);
+	for(uint8_t i = 0; i < WSPR_LENGTH; i++) {
+		if(test1[i] == validation[i]) {
+			printf("%d✓", test1[i]);
+		}
+		else {
+			printf("%d✗", test1[i]);
+		}
 	}
 	printf("\n");