pascallanger · rdba2k · Dec 11, 2025 · Feb 14, 2026 · Feb 14, 2026 · Feb 14, 2026
diff --git a/Multiprotocol/FX_nrf24l01.ino b/Multiprotocol/FX_nrf24l01.ino
@@ -42,6 +42,9 @@ Multiprotocol is distributed in the hope that it will be useful,
 #define FX_QF012_PACKET_PERIOD		12194
 #define FX_QF012_RX_PAYLOAD_SIZE	3
 
+#define FX_BM26_BIND_CHANNEL		40      
+#define FX_BM26_PACKET_PERIOD		14066
+
 //#define FORCE_FX620_ID
 //#define FORCE_FX9630_ID
 //#define FORCE_QIDI_ID
@@ -90,6 +93,12 @@ static void __attribute__((unused)) FX_send_packet()
 		packet[1] = convert_channel_8b(AILERON);
 		packet[2] = 0xFF - convert_channel_8b(ELEVATOR);
 		packet[3] = convert_channel_8b(RUDDER);
+		if ( sub_protocol == FX_BM26 )  // BM26 Ail, Elev, Rud range between 0x00-0x3F-0x7F
+    	{
+			packet[1] >>= 1;
+			packet[2] >>= 1;
+			packet[3] >>= 1;
+    	}
 		val = trim_ch==0 ? 0x20 : (convert_channel_8b(trim_ch + CH6) >> 2);	// no trim on Throttle
 		packet[4] = val;			// Trim for channel x 0C..20..34
 		packet[5] = (trim_ch << 4)	// channel x << 4
@@ -103,6 +112,22 @@ static void __attribute__((unused)) FX_send_packet()
 		else if (sub_protocol == FX_QF012) 
       			packet[5] |=  GET_FLAG(CH7_SW, 0x40)  // QF012 invert flight
                 		    | GET_FLAG(CH8_SW, 0x80);  // QF012 Restore fine tunning midpoint
+		else if ( sub_protocol == FX_BM26 ) 
+		{
+			if ( packet_count == 0 || packet_count > 3 ) {
+				packet[5] = 0x00;
+				packet_count = 0;
+			}
+			else packet[5] += 0x40;
+			packet_count++;        
+			// BM26 P51=>0:beginner(6G), 1:mid(3D), 2:expert(Gyro off) 
+			packet[5] |= (Channel_data[CH6] < CHANNEL_MIN_COMMAND ? 0x08 : (Channel_data[CH6] > CHANNEL_MAX_COMMAND ? 0x0C : 0x0A));
+
+			packet[6] = (Channel_data[CH5] > CHANNEL_MAX_COMMAND ? 0x20 : 0x00 )  // 6G Roll
+        			  | (Channel_data[CH7] > CHANNEL_MAX_COMMAND ? 0x00 : 0x08 )  // Light control switch, default on
+            		  | (Channel_data[CH8] > CHANNEL_MAX_COMMAND ? 0x00 : 0x10 )  // Turn signal switch, default on
+        			  | (Channel_data[CH9] > CHANNEL_MAX_COMMAND ? 0x01 : 0x00 ); // Gyro Calibration
+    	}  
 	}
 	else // FX816 & FX620
 	{
@@ -164,6 +189,8 @@ static void __attribute__((unused)) FX_send_packet()
 		val = val ^ 0xFF;
 	packet[last_packet_idx]=val;
 
+	if ( IS_BIND_IN_PROGRESS && sub_protocol == FX_BM26 ) packet[7] = packet[6];
+
 	//Debug
 	#if 0
 		for(uint8_t i=0;i<packet_length;i++)
@@ -194,6 +221,13 @@ static void __attribute__((unused)) FX_RF_init()
 		packet_period = FX620_BIND_PACKET_PERIOD;
 		packet_length = FX620_PAYLOAD_SIZE;
 	}
+	else if (sub_protocol == FX_BM26)
+	{
+		XN297_SetTXAddr((uint8_t *)"\x12\x34\x10\x10", 4); 
+    	XN297_RFChannel(FX_BM26_BIND_CHANNEL); 
+    	packet_period = FX_BM26_PACKET_PERIOD;
+    	packet_length = FX9630_PAYLOAD_SIZE;
+	}
 	else // FX9630 & FX_Q560 & FX_QF012
 	{
 		XN297_SetTXAddr((uint8_t *)"\x56\x78\x90\x12", 4);
@@ -229,7 +263,7 @@ static void __attribute__((unused)) FX_initialize_txid()
 	else // FX9630 & FX_Q560 & FX_QF012
 	{
 		//??? Need to find out how the first RF channel is calculated ???
-		hopping_frequency[0] = 0x13;
+		hopping_frequency[0] = sub_protocol == FX_BM26? 0x0C : 0x13;
 		//Other 2 RF channels are sent during the bind phase so they can be whatever
 		hopping_frequency[1] = RX_num & 0x0F + 0x1A;
 		hopping_frequency[2] = rx_tx_addr[3] & 0x0F + 0x38;
@@ -245,7 +279,8 @@ static void __attribute__((unused)) FX_initialize_txid()
 			//memcpy(rx_tx_addr,(uint8_t*)"\x38\xC7\x6D\x8D", 4);
 			//memcpy(hopping_frequency,"\x0D\x20\x3A", FX9630_NUM_CHANNELS);
 		#endif
-	}
+		// BM26 rx_tx_addr: "\x17\x03\x00\x00", hopping_frequency: 0x0C,0x30,0x43(12,48,67)
+	} 
 }
 
 uint16_t FX_callback()
@@ -288,9 +323,9 @@ uint16_t FX_callback()
 					debug("RX");
 					if(XN297_ReadPayload(packet_in, FX_QF012_RX_PAYLOAD_SIZE))
 					{//Good CRC
-						//packets: A5 00 11 -> A5 01 11
 						telemetry_link = 1;
-						v_lipo1 = packet_in[1] ? 60:81;		// low voltage 3.7V
+						if ( sub_protocol == FX_BM26 ) v_lipo1 = packet_in[0] <  packet_in[2]? 60:81;  // packets: AA 00 55 -> 55 00 AA
+						else v_lipo1 = packet_in[1] ? 60:81;	//packets: A5 00 11 -> A5 01 11	// low voltage 3.7V
 						#if 0
 							for(uint8_t i=0; i < FX_QF012_RX_PAYLOAD_SIZE; i++)
 								debug(" %02X", packet_in[i]);
@@ -328,6 +363,7 @@ void FX_init()
 	FX_RF_init();
 	hopping_frequency_no = 0;
 	bind_counter=FX_BIND_COUNT;
+	packet_count = 0;
 	#ifdef FX_HUB_TELEMETRY
 		RX_RSSI = 100;		// Dummy value
 		phase = FX_DATA;

diff --git a/Multiprotocol/Multi.txt b/Multiprotocol/Multi.txt
@@ -55,7 +55,7 @@
 55,Frsky_RX,Multi,CloneTX,EraseTX,CPPM
 56,AFHDS2A_RX,Multi,CPPM
 57,HoTT,Sync,No_Sync
-58,FX,816,620,9630,Q560,QF012
+58,FX,816,620,9630,Q560,QF012,BM26
 59,Bayang_RX,Multi,CPPM
 60,Pelikan,Pro,Lite,SCX24
 61,EazyRC
@@ -102,3 +102,4 @@
 104,KAMTOM
 105,Shenqi2
 106,WL91x
+
diff --git a/Multiprotocol/Multi_Protos.ino b/Multiprotocol/Multi_Protos.ino
@@ -188,7 +188,7 @@ const char STR_SUBTYPE_JJRC345[] =    "\x08""JJRC345\0""SkyTmblr";
 const char STR_SUBTYPE_MOULDKG[] =    "\x05""A4444""D4444""A664\0";
 const char STR_SUBTYPE_KF606[] =      "\x06""KF606\0""MIG320""ZCZ50\0";
 const char STR_SUBTYPE_E129[] =       "\x04""E129""C186";
-const char STR_SUBTYPE_FX[] =         "\x05""816\0 ""620\0 ""9630\0""Q560\0""QF012";
+const char STR_SUBTYPE_FX[] =         "\x05""816\0 ""620\0 ""9630\0""Q560\0""QF012""BM26\0";
 const char STR_SUBTYPE_SGF22[] =      "\x04""F22\0""F22S""J20\0""CX10";
 const char STR_SUBTYPE_JIABAILE[] =   "\x04""Std\0""Gyro";
 #define NO_SUBTYPE		nullptr
@@ -345,7 +345,7 @@ const mm_protocol_definition multi_protocols[] = {
 		{PROTO_FUTABA,     STR_FUTABA,    STR_SUBTYPE_FUTABA,    1, OPTION_RFTUNE,  1, 1, SW_CC2500, SFHSS_init,      SFHSS_callback      },
 	#endif
 	#if defined(FX_NRF24L01_INO)
-		{PROTO_FX,         STR_FX,        STR_SUBTYPE_FX,        5, OPTION_NONE,    0, 0, SW_NRF,    FX_init,         FX_callback         },
+		{PROTO_FX,         STR_FX,        STR_SUBTYPE_FX,        6, OPTION_NONE,    0, 0, SW_NRF,    FX_init,         FX_callback         },
 	#endif
 	#if defined(FY326_NRF24L01_INO)
 		{PROTO_FY326,      STR_FY326,     STR_SUBTYPE_FY326,     2, OPTION_NONE,    0, 0, SW_NRF,    FY326_init,      FY326_callback      },

diff --git a/Multiprotocol/Multiprotocol.h b/Multiprotocol/Multiprotocol.h
@@ -493,6 +493,7 @@ enum FX
     FX9630          = 2,
 	FX_Q560			= 3,
 	FX_QF012		= 4,
+	FX_BM26			= 5,
 };
 enum SGF22
 {

diff --git a/Multiprotocol/XK2_ccnrf.ino b/Multiprotocol/XK2_ccnrf.ino
@@ -86,6 +86,8 @@ static void __attribute__((unused)) XK2_send_packet()
 			packet[5] |= 0x10;											//Gyro off (senior mode)
 		else if(Channel_data[CH6] > CHANNEL_MIN_COMMAND)
 			packet[5] |= 0x08;											//3D
+		packet[5] |= GET_FLAG(CH9_SW, 0x04) ;     						//SkyViper Vector stunt flag
+		//SkyViper Vector: Telemetry A1 value is changed from 8.4v to 7.1v when the battery voltage is less than 3.3v
 		//Requiest telemetry flag
 		packet[6] = 0x01;
 		//RXID checksum
@@ -428,4 +430,4 @@ P[6] = 00 telemetry nok
        01 telemetry ok but sometimes switch to 1 also when telemetry is nok...
 P[7] = C8 -> sum RX_ID[0..2] 
 P[8] = sum P[0..7] + TX_ID[0] - TX_ID[1] + TX_ID[2] + 21 +10
-*/
+*/
diff --git a/Multiprotocol/_Config.h b/Multiprotocol/_Config.h
@@ -699,6 +699,7 @@ const PPM_Parameters PPM_prot[14*NBR_BANKS]=	{
 		FX9630
 		Q560
 		QF012
+		BM26
 	PROTO_FY326
 		FY326
 		FY319

diff --git a/Protocols_Details.md b/Protocols_Details.md
@@ -99,7 +99,7 @@ CFlie|AIR|38|CFlie||||||||NRF24L01|
 [FrskyX2](Protocols_Details.md#FRSKYX2---64)||64|CH_16|CH_8|EU_16|EU_8|Cloned|Cloned_8|||CC2500|
 [Frsky_RX](Protocols_Details.md#FRSKY_RX---55)||55|Multi|CloneTX|EraseTX|CPPM|||||CC2500|
 [Futaba/SFHSS](Protocols_Details.md#Futaba---21)||21|SFHSS||||||||CC2500|
-[FX](Protocols_Details.md#FX---58)||28|816|620|9630|Q560|QF012||||NRF24L01|
+[FX](Protocols_Details.md#FX---58)||28|816|620|9630|Q560|QF012|BM26|||NRF24L01|
 [FY326](Protocols_Details.md#FY326---20)||20|FY326|FY319|||||||NRF24L01|
 [GD00X](Protocols_Details.md#GD00X---47)||47|GD_V1*|GD_V2*|||||||NRF24L01|XN297L
 [GW008](Protocols_Details.md#GW008---32)||32|||||||||NRF24L01|XN297
@@ -1574,9 +1574,9 @@ If a CC2500 is installed it will be used for this sub protocol. Option in this c
 
 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.
 
-CH1|CH2|CH3|CH4|CH5|CH6|CH7|CH8
----|---|---|---|---|---|---|---
-A|E|T|R|Rate|Mode|Hover|Light
+CH1|CH2|CH3|CH4|CH5|CH6|CH7|CH8|CH9
+---|---|---|---|---|---|---|---|---
+A|E|T|R|Rate|Mode|Hover|Light|Stunt
 
 The plane does not need to be bound each time if it is powered on **after** the radio/protocol is on.
 
@@ -1586,6 +1586,8 @@ The rudder trim is driven from the rudder channel to increase the range (Origina
 
 Mode: -100%=6G, 0%=3D, +100%=Gyro off (Senior mode)
 
+CH9 - Stunt is for SkyViper Vector.
+
 ### Sub_protocol X4 - *0*
 Transmitter: XK X4-A160, X5S, model: XK A160S, XK A280, XK A300
 
@@ -1890,6 +1892,17 @@ Gyro: -100%=6G, 0%=3D+Gyro, +100%=3D
 
 Reset: Restore fine tunning midpoint
 
+### Sub_protocol BM26 - *5*
+Model: BM26 P51
+
+Telemetry supported. The plane sends a battery status of good->empty which is visible in A1 (good=4.2V->empty=3.1V) and RSSI gets a dummy value of 100.
+
+CH1|CH2|CH3|CH4|CH5|CH6|CH7|CH8|CH9
+---|---|---|---|---|---|---|---|---
+A|E|T|R|FLIP|GYRO|Light Switch|Turning Light switch|Gyro Calibration
+
+Gyro: -100%=6G, 0%=3D+Gyro, +100%=3D
+
 ## FY326 - *20*
 
 ### Sub_protocol FY326 - *0*
-Original file line number
+Diff line change
@@ Expand Up / @@ -699,6 +699,7 @@ const PPM_Parameters PPM_prot[14*NBR_BANKS]= { @@
     		FX9630
     		Q560
     		QF012
+    		BM26
     	PROTO_FY326
     		FY326
     		FY319
@@ Expand Down @@