RDS radiotext and time group generators

firmware/application/rds.cpp

@@ -24,19 +24,24 @@
 
 #include "portapack_shared_memory.hpp"
 
+// RDS infos:
+// One group = 4 blocks = 4 * 26 bits
+// One block = 26 bits (16 bits data + 10 bits checkword)
+// Sent MSB first
+
 namespace rds {
 
-uint32_t makeblock(uint32_t blockdata, uint16_t offset) {
+uint32_t makeblock(uint32_t data, uint16_t offset) {
     uint16_t CRC = 0;
-    uint8_t doinv;
+    uint8_t bit;
     
     for (uint8_t i = 0; i < 16; i++) {
-        doinv = (((blockdata << i) & 0x8000) >> 15) ^ (CRC >> 9);
+        bit = (((data << i) & 0x8000) >> 15) ^ (CRC >> 9);
-        if (doinv) CRC ^= 0b0011011100;
+        if (bit) CRC ^= 0b0011011100;
-        CRC = ((CRC << 1) | doinv) & 0x3FF;
+        CRC = ((CRC << 1) | bit) & 0x3FF;
     }
     
-    return (blockdata << 10) | (CRC ^ offset);
+    return (data << 10) | (CRC ^ offset);
 }
 
 // Todo:
@@ -52,35 +57,50 @@ uint8_t b2b(const bool in) {
 		return 0;
 }
 
-void make_0B_group(uint32_t group[], const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool TA,
+// Type 0B groups are like 0A groups but without alternative frequency data
+void make_0B_group(uint32_t blocks[], const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool TA,
 							const bool MS, const bool DI, const uint8_t C, const char * chars) {
-
+	blocks[0] = PI_code;
-	group[0] = PI_code;
+	blocks[1] = (0x0 << 12) | (1 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | (b2b(TA) << 4) | (b2b(MS) << 3) | (b2b(DI) << 2) | (C & 3);
-	group[1] = (0x0 << 12) | (1 << 11) | (b2b(TP) << 10) | (PTY << 5) | (b2b(TA) << 4) | (b2b(MS) << 3) | (b2b(DI) << 2) | (C & 3);
+	blocks[2] = PI_code;
-	group[2] = PI_code;
+	blocks[3] = (chars[0] << 8) | chars[1];
-	group[3] = (chars[0] << 8) | chars[1];
 }
 
-void make_2A_group(uint32_t group[], const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool AB,
+// For RadioText, up to 64 chars with 2A, 32 chars with 2B
+void make_2A_group(uint32_t blocks[], const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool AB,
 							const uint8_t segment, const char * chars) {
-
+	blocks[0] = PI_code;
-	group[0] = PI_code;
+	blocks[1] = (0x2 << 12) | (0 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | (b2b(AB) << 4) | (segment & 15);
-	group[1] = (0x0 << 12) | (1 << 11) | (b2b(TP) << 10) | (PTY << 5) | (b2b(AB) << 4) | (segment & 15);
+	blocks[2] = (chars[0] << 8) | chars[1];
-	group[2] = (chars[0] << 8) | chars[1];
+	blocks[3] = (chars[2] << 8) | chars[3];
-	group[3] = (chars[2] << 8) | chars[3];
 }
 
-uint16_t gen_PSN(const char * psname, const uint8_t pty) {
+// Time and date - usually one message per minute - Month: 1~12 - Day: 1~31 - Hour/Minute: 0~59 - Local offset: -12/+12 from UTC
+void make_4A_group(uint32_t blocks[], const uint16_t PI_code, const bool TP, const uint8_t PTY,
+							const uint16_t year, const uint8_t month, const uint8_t day,
+							const uint8_t hour, const uint8_t minute, const int8_t local_offset) {
+	uint32_t L = 0;
+	uint32_t day_code;
+	
+	if ((month == 1) || (month == 2)) L = 1;
+	
+	day_code = 14956 + day + (uint32_t)((float)(year - L) * 365.25) + uint16_t(((month + 1) * L * 12) * 30.6001);
+	
+	blocks[0] = PI_code;
+	blocks[1] = (0x4 << 12) | (0 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | ((day_code & 0x18000) >> 15);
+	blocks[2] = ((day_code & 0x7FFF) << 1) | (hour >> 4);
+	blocks[3] = ((hour & 15) << 12) | ((minute & 0x3F) << 6) | (local_offset & 0x3F);
+}
+
+uint16_t gen_PSN(const char * psname, const RDS_flags * rds_flags) {
 	uint8_t c;
 	uint32_t group[4][4] = { 0 };
 	
 	// 4 groups with 2 PSN characters in each
-	make_0B_group(&group[0][0], 0xF849, true, pty, false, true, false, 0, &psname[0]);
+	for (c = 0; c < 4; c++)
-	make_0B_group(&group[1][0], 0xF849, true, pty, false, true, false, 1, &psname[2]);
+	make_0B_group(&group[c][0], rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, rds_flags->TA, rds_flags->MS, rds_flags->DI, c, &psname[c * 2]);
-	make_0B_group(&group[2][0], 0xF849, true, pty, false, true, false, 2, &psname[4]);
-	make_0B_group(&group[3][0], 0xF849, true, pty, false, true, false, 3, &psname[6]);
 	
-	// Generate checkbits for all blocks
+	// Generate checkbits for each block of each group
 	for (c = 0; c < 4; c++) {
 		group[c][0] = makeblock(group[c][0], RDS_OFFSET_A);
 		group[c][1] = makeblock(group[c][1], RDS_OFFSET_B);
@@ -90,36 +110,38 @@ uint16_t gen_PSN(const char * psname, const uint8_t pty) {
 	
 	uint32_t * tx_data_u32 = (uint32_t*)shared_memory.tx_data;
 	
+	// Copy to tx_data for baseband
 	for (c = 0; c < 4 * 4; c++)
 		tx_data_u32[c] = group[c >> 2][c & 3];
 	
 	return 4 * 4 * 26;
 }
 
-uint16_t gen_RadioText(const char * radiotext, const uint8_t pty) {
+uint16_t gen_RadioText(const char * text,  const bool AB, const RDS_flags * rds_flags) {
 	size_t c, i;
 	uint32_t * group;
 	char radiotext_buffer[65] = { 0 };
 	uint8_t rtlen, groups;
 	
-	strcpy(radiotext_buffer, radiotext);
+	strncpy(radiotext_buffer, text, 64);
 	
 	rtlen = strlen(radiotext_buffer);
 	
-	radiotext_buffer[rtlen] = 0x0D;
+	// Pad message with spaces to a multiple of 4 characters
-	
-	// Pad to multiple of 4
 	while (rtlen & 3)
 		radiotext_buffer[rtlen++] = ' ';
 
+	// End message with Carriage Return, as required
+	if (rtlen < 64) radiotext_buffer[rtlen] = 0x0D;
+	
 	groups = rtlen >> 2;	// 4 characters per group
 
-	group = (uint32_t*)chHeapAlloc(0x0, 4 * groups * sizeof(uint32_t));
+	group = (uint32_t*)chHeapAlloc(0, 4 * groups * sizeof(uint32_t));
 
 	for (c = 0; c < groups; c++)
-		make_2A_group(&group[c << 2], 0xF849, true, pty, false, c, &radiotext_buffer[c * 4]);
+		make_2A_group(&group[c * 4], rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, AB, c, &radiotext_buffer[c * 4]);
 
-	// Generate checkbits
+	// Generate checkbits for each block of each group
 	for (c = 0; c < groups; c++) {
 		i = c * 4;
 		group[i + 0] = makeblock(group[i + 0], RDS_OFFSET_A);
@@ -130,10 +152,36 @@ uint16_t gen_RadioText(const char * radiotext, const uint8_t pty) {
 	
 	uint32_t * tx_data_u32 = (uint32_t*)shared_memory.tx_data;
 	
+	// Copy to tx_data for baseband
 	for (c = 0; c < (groups * 4); c++)
 		tx_data_u32[c] = group[c];
 	
+	chHeapFree(group);
+	
 	return groups * 4 * 26;
 }
 
+uint16_t gen_ClockTime(const RDS_flags * rds_flags,
+						const uint16_t year, const uint8_t month, const uint8_t day,
+						const uint8_t hour, const uint8_t minute, const int8_t local_offset) {
+	uint8_t c;
+	uint32_t group[4] = { 0 };
+	
+	make_4A_group(&group[0], rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, year, month, day, hour, minute, local_offset);
+	
+	// Generate checkbits for each block
+	group[0] = makeblock(group[0], RDS_OFFSET_A);
+	group[1] = makeblock(group[1], RDS_OFFSET_B);
+	group[2] = makeblock(group[2], RDS_OFFSET_C);
+	group[3] = makeblock(group[3], RDS_OFFSET_D);
+	
+	uint32_t * tx_data_u32 = (uint32_t*)shared_memory.tx_data;
+	
+	// Copy to tx_data for baseband
+	for (c = 0; c < 4; c++)
+		tx_data_u32[c] = group[c];
+	
+	return 4 * 26;			
+}
+
 } /* namespace rds */

firmware/application/rds.hpp

@@ -35,14 +35,30 @@ namespace rds {
 #define RDS_OFFSET_Cp	0b1101010000
 #define RDS_OFFSET_D	0b0110110100
 
+struct RDS_flags {
+	uint16_t PI_code;
+	bool TP;
+	uint8_t PTY;
+	bool TA;
+	bool MS;
+	bool DI;
+};
+
 uint32_t makeblock(uint32_t blockdata, uint16_t offset);
 uint8_t b2b(const bool in);
 void make_0B_group(uint32_t group[], const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool TA,
 							const bool MS, const bool DI, const uint8_t C, const char * chars);
 void make_2A_group(uint32_t group[], const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool AB,
 							const uint8_t segment, const char * chars);
-uint16_t gen_PSN(const char * psname, const uint8_t pty);
+void make_4A_group(uint32_t blocks[], const uint16_t PI_code, const bool TP, const uint8_t PTY,
-uint16_t gen_RadioText(const char * radiotext, const uint8_t pty);
+							const uint16_t year, const uint8_t month, const uint8_t day,
+							const uint8_t hour, const uint8_t minute, const int8_t local_offset);
+
+uint16_t gen_PSN(const char * psname, const RDS_flags * rds_flags);
+uint16_t gen_RadioText(const char * text, const bool AB, const RDS_flags * rds_flags);
+uint16_t gen_ClockTime(const RDS_flags * rds_flags,
+						const uint16_t year, const uint8_t month, const uint8_t day,
+						const uint8_t hour, const uint8_t minute, const int8_t local_offset);
 
 } /* namespace rds */
 

firmware/application/ui_rds.cpp

@@ -22,7 +22,6 @@
 
 #include "ui_rds.hpp"
 
-#include "rds.hpp"
 #include "portapack.hpp"
 #include "baseband_api.hpp"
 #include "portapack_shared_memory.hpp"
@@ -115,24 +114,28 @@ RDSView::RDSView(NavigationView& nav) {
 	options_countrycode.set_selected_index(18);		// France
 	options_coverage.set_selected_index(0);			// Local
 	
-	button_editpsn.on_select = [this,&nav](Button&){
+	options_pty.on_change = [this](size_t, int32_t v) {
+		rds_flags.PTY = v;
+	};
+	
+	button_editpsn.on_select = [this,&nav](Button&) {
 		textentry(nav, PSN, 8);
 	};
-	button_txpsn.on_select = [this](Button&){
+	button_txpsn.on_select = [this](Button&) {
 		if (txing) {
 			button_txpsn.set_text("PSN");
 			button_txradiotext.set_text("Radiotext");
 			transmitter_model.disable();
 			txing = false;
 		} else {
-			message_length = gen_PSN(PSN, options_pty.selected_index());
+			message_length = gen_PSN(PSN, &rds_flags);
 			button_txpsn.set_text("STOP");
 			txing = true;
 			start_tx();
 		}
 	};
 	
-	button_editradiotext.on_select = [this,&nav](Button&){
+	button_editradiotext.on_select = [this, &nav](Button&){
 		textentry(nav, RadioText, 24);
 	};
 	button_txradiotext.on_select = [this](Button&){
@@ -142,7 +145,7 @@ RDSView::RDSView(NavigationView& nav) {
 			transmitter_model.disable();
 			txing = false;
 		} else {
-			message_length = gen_RadioText(RadioText, options_pty.selected_index());
+			message_length = gen_RadioText(RadioText, 0, &rds_flags);
 			button_txradiotext.set_text("STOP");
 			txing = true;
 			start_tx();

firmware/application/ui_rds.hpp

@@ -27,6 +27,9 @@
 #include "ui_receiver.hpp"
 #include "ui_textentry.hpp"
 #include "message.hpp"
+#include "rds.hpp"
+
+using namespace rds;
 
 namespace ui {
 
@@ -44,6 +47,7 @@ private:
 	char PSN[9];
 	char RadioText[25];
 	bool txing = false;
+	RDS_flags rds_flags;
 	
 	uint16_t message_length;