From b67b440ede37d48dffa0187b32ee1584bee7b986 Mon Sep 17 00:00:00 2001
From: Paul Kendall <pkendall64@gmail.com>
Date: Mon, 9 Jan 2023 15:28:50 +1300
Subject: [PATCH 1/2] Add support for returning TX backpack version

---
 lib/MSP/msp.cpp    |  5 ++++-
 lib/MSP/msp.h      |  6 +-----
 lib/MSP/msptypes.h |  3 +++
 src/Tx_main.cpp    | 17 +++++++++++++++++
 4 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/lib/MSP/msp.cpp b/lib/MSP/msp.cpp
index ff1ac10..04b2e8e 100644
--- a/lib/MSP/msp.cpp
+++ b/lib/MSP/msp.cpp
@@ -97,7 +97,10 @@ MSP::processReceivedByte(uint8_t c)
                 m_packet.flags = header->flags;
                 // reset the offset iterator for re-use in payload below
                 m_offset = 0;
-                m_inputState = MSP_PAYLOAD_V2_NATIVE;
+                if (m_packet.payloadSize == 0)
+                    m_inputState = MSP_CHECKSUM_V2_NATIVE;
+                else
+                    m_inputState = MSP_PAYLOAD_V2_NATIVE;
             }
             break;
 
diff --git a/lib/MSP/msp.h b/lib/MSP/msp.h
index db51b06..7e99ee0 100644
--- a/lib/MSP/msp.h
+++ b/lib/MSP/msp.h
@@ -2,11 +2,7 @@
 
 #include <Arduino.h>
 
-// TODO: MSP_PORT_INBUF_SIZE should be changed to
-// dynamically allocate array length based on the payload size
-// Hardcoding payload size to 8 bytes for now, since MSP is
-// limited to a 4 byte payload on the BF side
-#define MSP_PORT_INBUF_SIZE 8
+#define MSP_PORT_INBUF_SIZE 32
 
 #define CHECK_PACKET_PARSING() \
   if (packet->readError) {\
diff --git a/lib/MSP/msptypes.h b/lib/MSP/msptypes.h
index 5a59156..63768d1 100644
--- a/lib/MSP/msptypes.h
+++ b/lib/MSP/msptypes.h
@@ -16,6 +16,9 @@
 #define MSP_ELRS_REQU_VTX_PKT                   0x0B
 #define MSP_ELRS_SET_TX_BACKPACK_WIFI_MODE      0x0C
 #define MSP_ELRS_SET_VRX_BACKPACK_WIFI_MODE     0x0D
+#define MSP_ELRS_SET_RX_WIFI_MODE               0x0E
+#define MSP_ELRS_SET_RX_LOAN_MODE               0x0F
+#define MSP_ELRS_GET_BACKPACK_VERSION           0x10
 
 // CRSF encapsulated msp defines
 #define ENCAPSULATED_MSP_PAYLOAD_SIZE           4
diff --git a/src/Tx_main.cpp b/src/Tx_main.cpp
index 9f69b0d..7cd64b8 100644
--- a/src/Tx_main.cpp
+++ b/src/Tx_main.cpp
@@ -23,6 +23,8 @@ uint8_t broadcastAddress[6] = {0, 0, 0, 0, 0, 0};
 #endif
 uint8_t bindingAddress[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
+const uint8_t version[] = {LATEST_VERSION};
+
 connectionState_e connectionState = starting;
 unsigned long rebootTime = 0;
 
@@ -98,6 +100,17 @@ void OnDataRecv(uint8_t * mac_addr, uint8_t *data, uint8_t data_len)
   blinkLED();
 }
 
+void SendVersionResponse()
+{
+  mspPacket_t out;
+  out.reset();
+  out.makeResponse();
+  out.function = MSP_ELRS_GET_BACKPACK_VERSION;
+  for (size_t i=0 ; i<sizeof(version) ; i++)
+    out.addByte(version[i]);
+  msp.sendPacket(&out, &Serial);
+}
+
 void ProcessMSPPacketFromTX(mspPacket_t *packet)
 {
   if (packet->function == MSP_ELRS_BIND)
@@ -134,6 +147,10 @@ void ProcessMSPPacketFromTX(mspPacket_t *packet)
     DBGLN("Processing MSP_ELRS_SET_TX_BACKPACK_WIFI_MODE...");
     RebootIntoWifi();
     break;
+  case MSP_ELRS_GET_BACKPACK_VERSION:
+    DBGLN("Processing MSP_ELRS_GET_BACKPACK_VERSION...");
+    SendVersionResponse();
+    break;
   default:
     // transparently forward MSP packets via espnow to any subscribers
     sendMSPViaEspnow(packet);

From 330c7e3ab83063f077454f955de3746a25a40ee1 Mon Sep 17 00:00:00 2001
From: Paul Kendall <pkendall64@gmail.com>
Date: Sun, 12 Feb 2023 20:47:07 +1300
Subject: [PATCH 2/2] cleanup after review

---
 src/Tx_main.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Tx_main.cpp b/src/Tx_main.cpp
index 7cd64b8..6354172 100644
--- a/src/Tx_main.cpp
+++ b/src/Tx_main.cpp
@@ -106,8 +106,10 @@ void SendVersionResponse()
   out.reset();
   out.makeResponse();
   out.function = MSP_ELRS_GET_BACKPACK_VERSION;
-  for (size_t i=0 ; i<sizeof(version) ; i++)
+  for (size_t i = 0 ; i < sizeof(version) ; i++)
+  {
     out.addByte(version[i]);
+  }
   msp.sendPacket(&out, &Serial);
 }