FrSky X: SPORT polling

Mike's corrections to make SPORT working on Taranis.

Multiprotocol/FrSkyX_cc2500.ino

@@ -333,6 +333,11 @@ uint16_t initFrSkyX()
 	//rx_tx_addr[2]=0xFD;
 	//************************
 	frskyX_init();
+#if defined  SPORT_POLLING
+#ifdef INVERT_SERIAL
+	start_timer4() ;
+#endif
+#endif
 	//
 	if(IS_BIND_IN_PROGRESS)
 	{	   

Multiprotocol/Hitec_cc2500.ino

@@ -17,7 +17,7 @@
 
 #include "iface_cc2500.h"
 
-//#define HITEC_FORCE_ID	//Use the ID and hopping table from original dump
+//#define HITEC_FORCE_ID	//Use the ID and hopping table from the original dump
 
 #define HITEC_COARSE			0
 
@@ -158,7 +158,7 @@ static void __attribute__((unused)) HITEC_build_packet()
 		}
 		packet[19] = 0x08;	// packet number
 		packet[20] = 0x00;	// starts with 0x00 and after some time it alternates between 0x00 and 0xF5
-		packet[21] = 0x00;	// unknown when [20]=0xF5 then the value is 0xE0 or 0xDC
+		packet[21] = 0x00;	// unknown when [20]=0xF5 then this value is between 0xDB and 0xE0. TODO: test if it could be RSSI related?
 	}
 	else
 	{

Multiprotocol/Multiprotocol.h

@@ -19,7 +19,7 @@
 #define VERSION_MAJOR		1
 #define VERSION_MINOR		2
 #define VERSION_REVISION	0
-#define VERSION_PATCH_LEVEL	23
+#define VERSION_PATCH_LEVEL	24
 
 //******************
 // Protocols

Multiprotocol/Multiprotocol.ino

@@ -55,6 +55,11 @@
 	#include <SPI.h>
 	#include <EEPROM.h>	
 	HardwareTimer HWTimer2(2);
+#if defined  SPORT_POLLING
+#ifdef INVERT_TELEMETRY
+	HardwareTimer HWTimer4(4);
+#endif
+#endif
 	void PPM_decode();
 	void ISR_COMPB();
 	extern "C"

Multiprotocol/Telemetry.ino

@@ -91,6 +91,11 @@ static void multi_send_header(uint8_t type, uint8_t len)
 static void multi_send_status()
 {
 	#ifdef SPORT_POLLING
+	#ifdef INVERT_SERIAL
+		USART3_BASE->CR1 &= ~USART_CR1_TE ;
+		TX_INV_on;	//activate inverter for both serial TX and RX signals
+		USART3_BASE->CR1 |= USART_CR1_TE ;
+	#endif
 		rx_pause();
 	#endif
 	multi_send_header(MULTI_TELEMETRY_STATUS, 5);
@@ -476,6 +481,13 @@ const uint8_t PROGMEM Indices[] = {	0x00, 0xA1, 0x22, 0x83, 0xE4, 0x45,
 #ifdef MULTI_TELEMETRY
 	void sportSend(uint8_t *p)
 	{
+	#ifdef SPORT_POLLING
+	#ifdef INVERT_SERIAL
+		USART3_BASE->CR1 &= ~USART_CR1_TE ;
+		TX_INV_on;	//activate inverter for both serial TX and RX signals
+		USART3_BASE->CR1 |= USART_CR1_TE ;
+	#endif
+	#endif
 		multi_send_header(MULTI_TELEMETRY_SPORT, 9);
 		uint16_t crc_s = 0;
 		uint8_t x = p[0] ;
@@ -500,6 +512,13 @@ const uint8_t PROGMEM Indices[] = {	0x00, 0xA1, 0x22, 0x83, 0xE4, 0x45,
 	void sportSend(uint8_t *p)
 	{
 		uint16_t crc_s = 0;
+	#ifdef SPORT_POLLING
+	#ifdef INVERT_SERIAL
+		USART3_BASE->CR1 &= ~USART_CR1_TE ;
+		TX_INV_on;	//activate inverter for both serial TX and RX signals
+		USART3_BASE->CR1 |= USART_CR1_TE ;
+	#endif
+	#endif
 		Serial_write(START_STOP);//+9
 		Serial_write(p[0]) ;
 		for (uint8_t i = 1; i < 9; i++)
@@ -585,6 +604,33 @@ uint8_t nextID()
 	return poll_idx ;
 }
 
+#ifdef INVERT_SERIAL
+void start_timer4()
+{
+	TIMER4_BASE->PSC = 71;								// 72-1;for 72 MHZ / 1.0sec/(71+1)
+	TIMER4_BASE->CCER = 0 ;
+	TIMER4_BASE->DIER = 0 ;
+	TIMER4_BASE->CCMR1 = 0 ;
+	TIMER4_BASE->CCMR1 = TIMER_CCMR1_OC1M ;
+	HWTimer4.attachInterrupt(TIMER_CH1, __irq_timer4);		// Assign function to Timer2/Comp2 interrupt
+	nvic_irq_set_priority( NVIC_TIMER4, 14 ) ;
+}
+
+void stop_timer4()
+{
+	TIMER5_BASE->CR1 = 0 ;
+	nvic_irq_disable( NVIC_TIMER4 ) ;
+}
+
+void __irq_timer4(void)			
+{
+	TIMER4_BASE->DIER = 0 ;
+	TIMER4_BASE->CR1 = 0 ;
+	TX_INV_on;	//activate inverter for both serial TX and RX signals
+}
+
+#endif
+
 void pollSport()
 {
 	uint8_t pindex = nextID() ;
@@ -597,12 +643,25 @@ void pollSport()
 	}		
 	SportIndexPolling = pindex ;
 	RxIndex = 0;
+	#ifdef INVERT_SERIAL
+		USART3_BASE->CR1 &= ~USART_CR1_TE ;
+		TX_INV_on;	//activate inverter for both serial TX and RX signals
+		USART3_BASE->CR1 |= USART_CR1_TE ;
+	#endif
 #ifdef MULTI_TELEMETRY
 	multi_send_header(MULTI_TELEMETRY_SPORT_POLLING, 1);
 #else
     Serial_write(TxData[0]);
 #endif
+	RxIndex=0;
 	Serial_write(TxData[1]);
+	USART3_BASE->CR1 |= USART_CR1_TCIE ;
+#ifdef INVERT_SERIAL
+	TIMER4_BASE->CNT = 0 ;
+	TIMER4_BASE->CCR1 = 3000 ;
+	TIMER4_BASE->DIER = TIMER_DIER_CC1IE ;
+	TIMER4_BASE->CR1 = TIMER_CR1_CEN ;
+#endif
 }
 
 bool checkSportPacket()
@@ -1039,6 +1098,15 @@ void TelemetryUpdate()
 	{	// Transmit interrupt
 		#ifdef STM32_BOARD
 			#ifdef SPORT_POLLING		
+				if(USART3_BASE->SR & USART_SR_TC) 
+				{
+					if ( USART3_BASE->CR1 & USART_CR1_TCIE )
+					{
+						USART3_BASE->CR1 &= ~USART_CR1_TCIE ;
+						TX_INV_off;
+					}
+				}
+
 				if(USART3_BASE->SR & USART_SR_RXNE) 
 				{
 					USART3_BASE->SR &= ~USART_SR_RXNE;

Multiprotocol/_Config.h

@@ -89,8 +89,8 @@
 //#define ORANGE_TX_BLUE
 
 /** CC2500 Fine Frequency Tuning **/
-//For optimal performance the CC2500 RF module used by the FrSkyD, FrSkyV, FrSkyX, and SFHSS protocols needs to be tuned for each protocol.
+//For optimal performance the CC2500 RF module used by the FrSkyD, FrSkyV, FrSkyX, SFHSS, CORONA and Hitec protocols needs to be tuned for each protocol.
-//Initial tuning should be done via the radio menu with a genuine FrSky or Futaba receiver.  
+//Initial tuning should be done via the radio menu with a genuine FrSky/Futaba/CORONA/Hitec receiver.  
 //Once a good tuning value is found it can be set here and will override the radio's 'option' setting for all existing and new models which use that protocol.
 //For more information: https://github.com/pascallanger/DIY-Multiprotocol-TX-Module/tree/master/docs/Frequency_Tuning.md
 //Uncomment the lines below (remove the "//") and set an appropriate value (replace the "0") to enable. Valid range is -127 to +127.