Merge pull request #7 from dmadison/api-tweaks

USB API Tweaks

Author: dmadison

src/XInput.cpp

@@ -326,43 +326,46 @@ boolean XInputGamepad::connected() {
 }
 
 //Send an update packet to the PC
-size_t XInputGamepad::send() {
+int XInputGamepad::send() {
 	if (!newData) return 0;  // TX data hasn't changed
 #ifdef USB_XINPUT
-	XInputUSB::send(tx, USB_Timeout);
 	newData = false;
+	return XInputUSB::send(tx, sizeof(tx));
 #else
 	#warning "Using debug output for XInput send()"
 	printDebug();
-#endif
 	return sizeof(tx);
+#endif
 }
 
-size_t XInputGamepad::receive() {
+int XInputGamepad::receive() {
 #ifdef USB_XINPUT
 	if (XInputUSB::available() == 0) {
 		return 0;  // No packet available
 	}
 
 	// Grab packet and store it in rx array
 	uint8_t rx[8];
-	size_t bytesRecv = XInputUSB::recv(rx, USB_Timeout);
-
-	const uint8_t PacketType = rx[0];
-	
-	// Rumble Packet
-	if(PacketType == (uint8_t) XInputReceiveType::Rumble) {
-		rumble[RumbleLeft.bufferIndex]  = rx[RumbleLeft.rxIndex];   // Big weight (Left grip)
-		rumble[RumbleRight.bufferIndex] = rx[RumbleRight.rxIndex];  // Small weight (Right grip)
-	}
-	// LED Packet
-	else if (PacketType == (uint8_t) XInputReceiveType::LEDs) {
-		parseLED(rx[2]);
-	}
-
-	// User-defined receive callback
-	if (recvCallback != nullptr) {
-		recvCallback(PacketType);
+	const int bytesRecv = XInputUSB::recv(rx, sizeof(rx));
+
+	// Only process if received 3 or more bytes (min valid packet size)
+	if (bytesRecv >= 3) {
+		const uint8_t PacketType = rx[0];
+
+		// Rumble Packet
+		if (PacketType == (uint8_t)XInputReceiveType::Rumble) {
+			rumble[RumbleLeft.bufferIndex] = rx[RumbleLeft.rxIndex];   // Big weight (Left grip)
+			rumble[RumbleRight.bufferIndex] = rx[RumbleRight.rxIndex];  // Small weight (Right grip)
+		}
+		// LED Packet
+		else if (PacketType == (uint8_t)XInputReceiveType::LEDs) {
+			parseLED(rx[2]);
+		}
+
+		// User-defined receive callback
+		if (recvCallback != nullptr) {
+			recvCallback(PacketType);
+		}
 	}
 
 	return bytesRecv;

src/XInput.h

@@ -114,8 +114,8 @@ class XInputGamepad {
 
 	// USB IO
 	boolean connected();
-	size_t send();
-	size_t receive();
+	int send();
+	int receive();
 
 	// Control Input Ranges
 	struct Range { int32_t min; int32_t max; };
@@ -131,7 +131,6 @@ class XInputGamepad {
 	void printDebug(Print& output = Serial) const;
 
 private:
-	static const uint32_t USB_Timeout = 12840;  // Packet timeout, in milliseconds
 	uint8_t tx[20];  // USB transmit data
 	boolean newData;  // Flag for tx data changed