From 5d453ce20f01fb1a01d949ec49eae8ed16fa563a Mon Sep 17 00:00:00 2001
From: Bryan Mayland <bmayland@capnbry.net>
Date: Tue, 10 Oct 2023 13:52:32 -0400
Subject: [PATCH] Convert to more generic UDP service

---
 src/lib/WIFI/devWIFI.cpp      | 17 +++++++++++------
 src/lib/WIFI/wifiJoystick.cpp | 12 +++++-------
 src/lib/WIFI/wifiJoystick.h   | 16 ++++++++++++----
 3 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/src/lib/WIFI/devWIFI.cpp b/src/lib/WIFI/devWIFI.cpp
index 2ac062e2fd..f7f2565893 100644
--- a/src/lib/WIFI/devWIFI.cpp
+++ b/src/lib/WIFI/devWIFI.cpp
@@ -727,15 +727,20 @@ static void WebUploadForceUpdateHandler(AsyncWebServerRequest *request) {
 }
 
 #ifdef HAS_WIFI_JOYSTICK
-static void WebUStartWifiJoystick(AsyncWebServerRequest *request)
+static void WebUdpControl(AsyncWebServerRequest *request)
 {
-  if(request->hasArg("start"))
+  const String &action = request->arg("action");
+  if (action.equals("joystick_begin"))
   {
-    int32_t updateInterval = request->hasArg("updateInterval") ? request->arg("updateInterval").toInt() : JOYSTICK_DEFAULT_UPDATE_INTERVAL;
+    int32_t updateInterval = request->hasArg("interval") ? request->arg("interval").toInt() : JOYSTICK_DEFAULT_UPDATE_INTERVAL;
     uint32_t channelCount = request->hasArg("channels") ? request->arg("channels").toInt() : JOYSTICK_DEFAULT_CHANNEL_COUNT;
     WifiJoystick::StartSending(request->client()->remoteIP(), updateInterval, channelCount);
     request->send(200, "text/plain", "ok");
   }
+  else if (action.equals("joystick_end"))
+  {
+    WifiJoystick::StopSending();
+  }
 }
 #endif
 
@@ -934,8 +939,8 @@ static void startMDNS()
   #endif
 
   #ifdef HAS_WIFI_JOYSTICK
-    MDNS.addService("elrs-joystick", "udp", JOYSTICK_PORT);
-    MDNS.addServiceTxt("elrs-joystick", "udp", "version", String(JOYSTICK_VERSION).c_str());
+    MDNS.addService("elrs", "udp", JOYSTICK_PORT);
+    MDNS.addServiceTxt("elrs", "udp", "version", String(JOYSTICK_VERSION).c_str());
   #endif
 }
 
@@ -993,7 +998,7 @@ static void startServices()
   server.on("/reboot", HandleReboot);
   server.on("/reset", HandleReset);
   #ifdef HAS_WIFI_JOYSTICK
-    server.on("/wifi_joystick", WebUStartWifiJoystick);
+    server.on("/udpcontrol", HTTP_POST, WebUdpControl);
   #endif
 
   server.addHandler(new AsyncCallbackJsonWebHandler("/config", UpdateConfiguration));
diff --git a/src/lib/WIFI/wifiJoystick.cpp b/src/lib/WIFI/wifiJoystick.cpp
index 21941fd27b..7acab75bfc 100644
--- a/src/lib/WIFI/wifiJoystick.cpp
+++ b/src/lib/WIFI/wifiJoystick.cpp
@@ -47,18 +47,18 @@ void WifiJoystick::StopJoystickService()
 
 void WifiJoystick::StartSending(const IPAddress& ip, int32_t updateInterval, uint8_t newChannelCount)
 {
-    if (!udp)
+    remoteIP = ip;
+    if (!udp || active)
     {
         return;
     }
-    remoteIP = ip;
 
     hwTimer::updateInterval(updateInterval);
     CRSF::setSyncParams(updateInterval);
     POWERMGNT::setPower(MinPower);
     Radio.End();
 
-    CRSF::RCdataCallback = UpdateValues;
+    CRSF::RCdataCallback = &UpdateValues;
     channelCount = newChannelCount;
 
     if (channelCount > 16)
@@ -101,9 +101,6 @@ void WifiJoystick::Loop(unsigned long now)
        udp->write((uint8_t*)device_name, eua.name_len);
        udp->endPacket();
     }
-
-    // Free any received data
-    udp->flush();
 }
 
 void WifiJoystick::UpdateValues()
@@ -123,7 +120,8 @@ void WifiJoystick::UpdateValues()
             CRSF_CHANNEL_VALUE_MIN, CRSF_CHANNEL_VALUE_MAX, 0, 0xffff));
         udp->write((uint8_t*)&channel, 2);
     }
-    udp->endPacket();
+
+    active = udp->endPacket() != 0;
 }
 
 #endif
diff --git a/src/lib/WIFI/wifiJoystick.h b/src/lib/WIFI/wifiJoystick.h
index 4bfe42084f..78b3273e54 100644
--- a/src/lib/WIFI/wifiJoystick.h
+++ b/src/lib/WIFI/wifiJoystick.h
@@ -17,7 +17,7 @@
  * Usage for simulator or driver on PC:
  *
  * Step 1: Find device. There are two options:
- *   Recommended: Use MDNS to query for a service called elrs-joystick to find out IP+Port, Protocol version can be found in service txt version
+ *   Recommended: Use MDNS to query for a UDP service called elrs to find out IP+Port, Protocol version can be found in service txt version
  *   Alternative: Listen for UDP broadcasts that contains a frame in the structure of
  *     4 bytes: ['E', 'L', 'R', 'S']
  *     1 byte: Protocol Version
@@ -29,9 +29,11 @@
  *   Start udp socket recvfrom(IP, PORT) discovered in Step 1
  *
  * Step 3:
- *   Send HTTP GET request to device in the form of http://<IP>/wifi_joystick?start=1&updateInterval=10000&channels=8
- *   updateInterval is in us
- *   channels defines how many channels are sent in each frame
+ *   Send HTTP POST request to device URL http://<IP>/udpcontrol
+ *   Param: "action" must be "joystick_begin"
+ *   Param: "interval" in us to send updates, or 0 for default (10ms)
+ *   Param: "channels" number of channels to send in each frame, or 0 for default (8)
+ *   e.g. http://<IP>/udpcontrol?action=joystick_begin&interval=10000&channels=8
  *
  * Step 3:
  *   receive frames in the format of:
@@ -39,7 +41,12 @@
  *   1 byte: Number of channels that follow
  *   2 bytes unsigned * channel count: Channel data in range 0 to 0xffff, network byte order
  *
+ * Step 4:
+ *  To end joystick data being sent, POST to the control URL
+ *  Param: "action" must be "joystick_end"
+ *  e.g http://<IP>/udpcontrol?action=joystick_end
  */
+
 class WifiJoystick
 {
 public:
@@ -50,6 +57,7 @@ class WifiJoystick
     static void StopJoystickService();
     static void UpdateValues();
     static void StartSending(const IPAddress& ip, int32_t updateInterval, uint8_t newChannelCount);
+    static void StopSending() { active = false; }
     static void Loop(unsigned long now);
 private:
     static WiFiUDP *udp;