Add fixed-ID MC8RE V2 A7105 protocol

Author: dududu009

Multiprotocol/MC8RE_a7105.ino

@@ -95,6 +95,7 @@ const char STR_RLINK[]		="RadLink";
 const char STR_REALACC[]	="Realacc";
 const char STR_OMP[]		="OMP";
 const char STR_MLINK[]		="M-Link";
+const char STR_MC8RE[]		="MC8RE V2";
 const char STR_TEST[]		="Test";
 const char STR_NANORF[]		="NanoRF";
 const char STR_E016HV2[]    ="E016Hv2";
@@ -431,6 +432,9 @@ const mm_protocol_definition multi_protocols[] = {
 	#if defined(MLINK_CYRF6936_INO)
 		{PROTO_MLINK,      STR_MLINK,     NO_SUBTYPE,            0, OPTION_NONE,    1, 0, SW_CYRF,   MLINK_init,      MLINK_callback      },
 	#endif
+	#if defined(MC8RE_A7105_INO)
+		{PROTO_MC8RE,      STR_MC8RE,     NO_SUBTYPE,            0, OPTION_NONE,    0, 0, SW_A7105,  MC8RE_init,      MC8RE_callback      },
+	#endif
 	#if defined(MOULDKG_NRF24L01_INO)
 		{PROTO_MOULDKG,    STR_MOULDKG,   STR_SUBTYPE_MOULDKG,   3, OPTION_OPTION,  0, 0, SW_NRF,    MOULDKG_init,    MOULDKG_callback    },
 	#endif

Multiprotocol/Multi_Protos.ino

@@ -136,6 +136,7 @@ enum PROTOCOLS
 	PROTO_WL91X		= 106,	// =>CC2500 & NRF24L01
 	PROTO_WPL		= 107,	// =>NRF24L01
 	PROTO_ARES		= 108,	// =>CC2500
+	PROTO_MC8RE		= 109,	// =>A7105
 
 	PROTO_NANORF	= 126,	// =>NRF24L01
 	PROTO_TEST		= 127,	// =>CC2500
@@ -597,6 +598,11 @@ enum MultiPacketTypes
 	MULTI_TELEMETRY_RLINK			= 18,
 };
 
+#if defined(MC8RE_A7105_INO)
+void MC8RE_init();
+uint16_t MC8RE_callback();
+#endif
+
 // Macros
 #define NOP() __asm__ __volatile__("nop")
 

Multiprotocol/Multiprotocol.h

@@ -326,6 +326,18 @@ static void multi_send_status()
 
 static void multi_send_frskyhub()
 {
+	#if defined(MC8RE_A7105_INO)
+		/* MC8RE V2 provides only A1/A2 plus the FrSky-D link marker.  A short
+		 * frame intentionally prevents EdgeTX from creating synthetic link
+		 * quality telemetry fields that this receiver does not transmit. */
+		if(protocol == PROTO_MC8RE && frame[0] == 0xFE)
+		{
+			multi_send_header(MULTI_TELEMETRY_HUB, 4);
+			for(uint8_t i = 0; i < 4; i++)
+				Serial_write(frame[i]);
+			return;
+		}
+	#endif
 	multi_send_header(MULTI_TELEMETRY_HUB, 9);
 	for (uint8_t i = 0; i < 9; i++)
 		Serial_write(frame[i]);

Multiprotocol/Telemetry.ino

@@ -257,6 +257,7 @@
 	#undef	HUBSAN_A7105_INO
 	#undef	JOYSWAY_A7105_INO
 	#undef	KYOSHO_A7105_INO
+	#undef	MC8RE_A7105_INO
 	#undef	PELIKAN_A7105_INO
 	#undef	WFLY2_A7105_INO
 #endif
@@ -418,6 +419,7 @@
 	#undef	BUGS_A7105_INO
 	#undef	HEIGHT_A7105_INO
 	#undef	HUBSAN_A7105_INO
+	#undef	MC8RE_A7105_INO
 	#undef	E010R5_CYRF6936_INO
 	#undef	E01X_CYRF6936_INO
 	#undef	E129_CYRF6936_INO

Multiprotocol/Validate.h

@@ -186,6 +186,7 @@
 #define	HUBSAN_A7105_INO
 #define	JOYSWAY_A7105_INO
 #define	KYOSHO_A7105_INO
+#define	MC8RE_A7105_INO
 #define	PELIKAN_A7105_INO
 #define	WFLY2_A7105_INO
 

Multiprotocol/_Config.h

@@ -126,6 +126,7 @@ CFlie|AIR|38|CFlie||||||||NRF24L01|
 [Losi](Protocols_Details.md#Losi---89)||89|||||||||CYRF6936|
 [MJXq](Protocols_Details.md#MJXQ---18)||18|WLH08|X600|X800|H26D|E010*|H26WH|PHOENIX*||NRF24L01|XN297
 [MLINK](Protocols_Details.md#MLINK---78)||78|||||||||CYRF6936|
+[MC8RE V2](Protocols_Details.md#MC8RE-V2---109)|AIR|109|||||||||A7105|
 [MouldKg](Protocols_Details.md#mouldkg---90)||90|A4444|D4444|A664||||||NRF24L01|XN297
 [MT99xx](Protocols_Details.md#MT99XX---17)||17|MT|H7|YZ|LS|FY805|A180|DRAGON|F949G|NRF24L01|XN297
 [MT99xx2](Protocols_Details.md#MT99XX2---92)||92|PA18|SU35|||||||NRF24L01|XN297
@@ -380,6 +381,20 @@ A|E|T|R|CH5|CH6
 
 RX output will match the Hype standard AETR independently of the input configuration AETR, RETA... unless on OpenTX 2.3.3+ you use the "Disable channel mapping" feature on the GUI.
 
+## MC8RE V2 - *109*
+
+MC8RE V2 receiver family.  Bind from the transmitter GUI, then set A1 to the
+receiver/BEC voltage and A2 to the external battery voltage.  Set A2's ratio
+to 25.5 V for a 4S voltage range.
+
+This protocol is fixed to the capture-proven transmitter identity and hopping
+sequence.  It is not yet a universal implementation for transmitters with a
+different original identity; see [MC8RE_V2.md](docs/MC8RE_V2.md).
+
+CH1|CH2|CH3|CH4|CH5|CH6|CH7|CH8
+---|---|---|---|---|---|---|---
+A|E|T|R|CH5|CH6|CH7|CH8
+
 ## Pelikan - *60*
 Extended limits supported
 

Protocols_Details.md

@@ -0,0 +1,35 @@
+# MC8RE V2 (A7105)
+
+This protocol supports the MC8RE V2 receiver family using an A7105 RF chip.
+It was reconstructed from a wired A7105 SPI capture of the original
+transmitter and then verified on two MC8RE V2 receivers.
+
+## Implemented behaviour
+
+- bind sequence: six packets on A7105 ID `5475C52A`, channel
+  `01`, then normal operation on ID `51D567EB`;
+- 16-channel hopping and the original startup/RX slot timing captured from
+  the transmitter;
+- eight 11-bit packed output channels, with EdgeTX +/-100% mapped to
+  1000/1500/2000 us;
+- telemetry A1 (receiver/BEC voltage) and A2 (external battery voltage,
+  0.1 V per count; set EdgeTX A2 ratio to 25.5 V for a 4S range);
+- a relative local A7105 RSSI indication.  It is not a calibrated received
+  signal-strength measurement supplied by the receiver.
+
+## Known limitation
+
+The normal link ID and hopping sequence are intentionally fixed to the
+capture-proven transmitter identity `51D567EB`.  Another original
+transmitter has been observed to use a different ID and hopping sequence.
+Deriving only the low 24 bits from the EdgeTX receiver number bound briefly
+but did not maintain control, so it is deliberately not exposed as an option.
+This is why this change is suitable for a **Draft PR / request for more
+captures**, rather than a claim of universal MC8RE compatibility.
+
+## Reproduction evidence
+
+The contributor can provide the original Saleae `.sal` wired capture on
+request.  Its SPI settings are CPOL=0, CPHA=0, MSB first; A7105 CS, SCK,
+MOSI and MISO were captured.  No receiver serial output or third-party RF
+packet decoder was used to infer the normal-channel format.