From 546a962d96ff9332795b6d79ae7f46f929ef6e35 Mon Sep 17 00:00:00 2001
From: pascallanger <pascal_langer@yahoo.fr>
Date: Mon, 20 Jan 2025 19:19:31 +0100
Subject: [PATCH] XK2 multi IDs

---
 Multiprotocol/Multiprotocol.h |  2 +-
 Multiprotocol/XK2_ccnrf.ino   | 50 +++++++++++++++++++----------------
 Protocols_Details.md          |  2 --
 3 files changed, 28 insertions(+), 26 deletions(-)

diff --git a/Multiprotocol/Multiprotocol.h b/Multiprotocol/Multiprotocol.h
index 936d877..ee66e1b 100644
--- a/Multiprotocol/Multiprotocol.h
+++ b/Multiprotocol/Multiprotocol.h
@@ -19,7 +19,7 @@
 #define VERSION_MAJOR		1
 #define VERSION_MINOR		3
 #define VERSION_REVISION	4
-#define VERSION_PATCH_LEVEL	19
+#define VERSION_PATCH_LEVEL	20
 
 #define MODE_SERIAL 0
 
diff --git a/Multiprotocol/XK2_ccnrf.ino b/Multiprotocol/XK2_ccnrf.ino
index 01463d5..b3e8b71 100644
--- a/Multiprotocol/XK2_ccnrf.ino
+++ b/Multiprotocol/XK2_ccnrf.ino
@@ -18,7 +18,7 @@ Multiprotocol is distributed in the hope that it will be useful,
 
 #include "iface_xn297.h"
 
-#define FORCE_XK2_ID
+//#define FORCE_XK2_ID
 
 #define XK2_RF_BIND_CHANNEL	71
 #define XK2_PAYLOAD_SIZE	9
@@ -75,15 +75,16 @@ static void __attribute__((unused)) XK2_send_packet()
 		//Telemetry not received=00, Telemetry received=01 but sometimes switch to 1 even if telemetry is not there...
 		packet[6] = 0x00;
 		//Unknown
-		packet[7] = crc8;												//?? RX_ID checksum ?? => sum RX_ID[0..2]
+		packet[7] = crc8;												//Sum RX_ID[0..2]
 		//Checksum seed
-		packet[8] = num_ch;												//Based on TX ID but calculation is unknown
+		packet[8] = num_ch;												//Based on TX ID
 	}
 	//Checksum
 	for(uint8_t i=0; i<XK2_PAYLOAD_SIZE-1; i++)
 		packet[8] += packet[i];
 
 	// Send
+	XN297_SetFreqOffset();
 	XN297_SetPower();
 	XN297_SetTxRxMode(TX_EN);
 	XN297_WritePayload(packet, XK2_PAYLOAD_SIZE);
@@ -109,28 +110,31 @@ static void __attribute__((unused)) XK2_RF_init()
 static void __attribute__((unused)) XK2_initialize_txid()
 {
 	#ifdef FORCE_XK2_ID
-	if(rx_tx_addr[3]&1)
-	{
-		rx_tx_addr[0] = 0x66;
-		rx_tx_addr[1] = 0x4F;
-		rx_tx_addr[2] = 0x47;
-		num_ch = 0x7F;				// Must be based on the ID but calculation unknow yet
-		//hopping frequencies 65=0x41, 69=0x45, 73=0x49, 77=0x4D
-	}
-	else
-	{
-		rx_tx_addr[0] = 0x36;
-		rx_tx_addr[1] = 0x49;
-		rx_tx_addr[2] = 0x6B;
-		num_ch = 0x79;				// Must be based on the ID but calculation unknow yet
-		//hopping frequencies 65=0x41, 69=0x45, 73=0x49, 77=0x4D
-	}
+		if(rx_tx_addr[3]&1)
+		{//Pascal
+			rx_tx_addr[0] = 0x66;
+			rx_tx_addr[1] = 0x4F;
+			rx_tx_addr[2] = 0x47;
+			num_ch = 0x7F;
+			//hopping frequencies 65=0x41, 69=0x45, 73=0x49, 77=0x4D
+		}
+		else
+		{//Marc
+			rx_tx_addr[0] = 0x36;
+			rx_tx_addr[1] = 0x49;
+			rx_tx_addr[2] = 0x6B;
+			num_ch = 0x79;
+			//hopping frequencies 65=0x41, 69=0x45, 73=0x49, 77=0x4D
+		}
 	#endif
-	for(uint8_t i=0;i<XK2_RF_NUM_CHANNELS;i++)	// Are these RF frequencies always the same?
+	rx_tx_addr[0] = rx_tx_addr[3];				// Use RX_num
+	rx_tx_addr[3] = rx_tx_addr[4] = 0xCC;
+	num_ch = 0x21 + rx_tx_addr[0] - rx_tx_addr[1] + rx_tx_addr[2];
+
+	for(uint8_t i=0;i<XK2_RF_NUM_CHANNELS;i++)	// Are these RF frequencies always the same? It looks like yes...
 		hopping_frequency[i] = 65 + i*4;		//65=0x41, 69=0x45, 73=0x49, 77=0x4D
-	rx_tx_addr[3] = 0xCC;
-	rx_tx_addr[4] = 0xCC;
-	debugln("ID: %02X %02X %02X %02X %02X , HOP: %02X %02X %02X %02X",rx_tx_addr[0],rx_tx_addr[1],rx_tx_addr[2],rx_tx_addr[3],rx_tx_addr[4],hopping_frequency[0],hopping_frequency[1],hopping_frequency[2],hopping_frequency[3]);
+
+	debugln("ID: %02X %02X %02X %02X %02X, OFFSET: %02X, HOP: %02X %02X %02X %02X",rx_tx_addr[0],rx_tx_addr[1],rx_tx_addr[2],rx_tx_addr[3],rx_tx_addr[4],num_ch,hopping_frequency[0],hopping_frequency[1],hopping_frequency[2],hopping_frequency[3]);
 }
 
 uint16_t XK2_callback()
diff --git a/Protocols_Details.md b/Protocols_Details.md
index cc5ffd7..2ecaec8 100644
--- a/Protocols_Details.md
+++ b/Protocols_Details.md
@@ -1517,8 +1517,6 @@ Models: WLtoys cars 284131/284161/284010/124016/124017/144010 and Eachine EAT14
 ### Sub_protocol X4 - *0*
 Transmitter: XK X4-A160, X5S, model: XK A160S, XK A280
 
-**Only 2 IDs**
-
 If a CC2500 is installed it will be used for this sub protocol. Option in this case is used for fine frequency tuning like any CC2500 protocols so check the [Frequency Tuning page](/docs/Frequency_Tuning.md).
 
 If only a NRF24L01 is installed then this sub protocol might be problematic because it is using the xn297L emulation with a transmission speed of 250kbps which doesn't work very well with every NRF24L01, this is an hardware issue with the authenticity and accuracy of the components.