added data structures

added audio support
added rfid support
added spi support

ext/audio/AudioData.h

@@ -0,0 +1,41 @@
+#ifndef AUDIODATA_H
+#define AUDIODATA_H
+
+#define min(a,b)		( (a<b) ? (a) : (b) )
+
+struct Data {
+	const uint8_t* data;
+	const uint32_t len;
+	Data(const uint8_t* data, const uint32_t len) : data(data), len(len) {;}
+};
+
+struct AudioData {
+
+	const uint8_t* data;
+	uint32_t available;
+
+	AudioData() : data(nullptr), available(0) {;}
+
+	AudioData(const uint8_t* data, const uint32_t len) : data(data), available(len) {
+
+	}
+
+	Data read(const uint32_t bytes) {
+		const uint32_t outBytes = min(bytes, this->available);
+		const uint8_t* ptr = this->data;
+		this->data += outBytes;
+		this->available -= outBytes;
+		return Data(ptr, outBytes);
+	}
+
+	uint32_t getNumBytesAvailable() const {
+		return available;
+	}
+
+	bool isEOF() const {
+		return available <= 0;
+	}
+
+};
+
+#endif // AUDIODATA_H