Use signed values for MIDI pitch bend (same as Arduino MIDI lib)

USBHost_t36.h

@@ -890,9 +890,13 @@ public:
 	void sendAfterTouch(uint8_t pressure, uint8_t channel, uint8_t cable=0) {
 		send(0xD0, pressure, 0, channel, cable);
 	}
-	void sendPitchBend(uint16_t value, uint8_t channel, uint8_t cable=0) {
-		// MIDI 4.3 takes -8192 to +8191.  We take 0 to 16383
-		// MIDI 4.3 also has version that takes float -1.0 to +1.0
+	void sendPitchBend(int value, uint8_t channel, uint8_t cable=0) {
+		if (value < -8192) {
+			value = -8192;
+		} else if (value > 8191) {
+			value = 8191;
+		}
+		value += 8192;
 		send(0xE0, value, value >> 7, channel, cable);
 	}
 	void sendSysEx(uint32_t length, const uint8_t *data, bool hasTerm=false, uint8_t cable=0) {

midi.cpp

@@ -430,7 +430,9 @@ bool MIDIDevice::read(uint8_t channel)
 		if (type1 == 0x0E && type2 == 0x0E) {
 			msg_type = 0xE0;		// 0xE0 = Pitch Bend
 			if (handlePitchChange) {
-				(*handlePitchChange)(ch, ((n >> 16) & 0x7F) | ((n >> 17) & 0x3F80));
+				int value = ((n >> 16) & 0x7F) | ((n >> 17) & 0x3F80);
+				value -= 8192; // 0 to 16383 --> -8192 to +8191
+				(*handlePitchChange)(ch, value);
 			}
 		} else {
 			return false;