diff --git a/ext/rf/SX1276.h b/ext/rf/SX1276.h
index bf0df4a..de5df37 100644
--- a/ext/rf/SX1276.h
+++ b/ext/rf/SX1276.h
@@ -130,8 +130,10 @@ template <typename SPI, int PIN_SLAVE_SEL, int PIN_RESET, int PIN_DIO0> class SX
 public:
 
 	struct PacketDetails {
-		int16_t rssi;	// can be smaller than -128!
-		float snr;
+		int8_t rssi;	// can be smaller than -128! -> use getter method (-128 - 1 -> + 127)
+		int8_t snr4;	// SNR*4 (must be scaled by 0.25)
+		float getSNR() const	{return snr4 * 0.25f;}
+		int16_t getRSSI() const	{return (rssi<0) ? (rssi) : (-256 + rssi);}
 	};
 
 public:
@@ -325,16 +327,17 @@ public:
 	
 	/** switch to idle mode */
 	void idle() {
-		debugMod(NAME, "idle()");
+		//debugMod(NAME, "idle()");
 		writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_STDBY);
 	}
 
 	/** switch to sleep mode */
 	void sleep() {
-		debugMod(NAME, "sleep()");
+		//debugMod(NAME, "sleep()");
 		writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_SLEEP);
 	}
 	
+	/** is the device currently transmitting? */
 	bool isTransmitting() {
 		if ((readRegister(REG_OP_MODE) & MODE_TX) == MODE_TX)	{return true;}
 		if (readRegister(REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK)		{writeRegister(REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);}	// clear TX-done IRQ flag
@@ -344,7 +347,7 @@ public:
 	/** send the given data */
 	int send(const uint8_t* data, uint8_t len, bool async) {
 		
-		debugMod1(NAME, "send(%d bytes)", len);
+		debugMod2(NAME, "tx(%d bytes, async:%d)", len, async);
 		
 		//if (len > MAX_PKT_LENGTH)	{return -1;}
 		if (isTransmitting())		{return 0;}
@@ -352,18 +355,14 @@ public:
 		// put in standby mode
 		idle();
 
-		//if (implicitHeader) {
-		//	implicitHeaderMode();
-		//} else {
-			explicitHeaderMode();
-		//}
-
+		explicitHeaderMode();
+		
 		// reset FIFO address and payload length
 		writeRegister(REG_FIFO_ADDR_PTR,	0);
 		writeRegister(REG_PAYLOAD_LENGTH,	0);
 		
 		// write data into FIFO
-		debugMod(NAME, "writing FIFO");
+		//debugMod(NAME, "writing FIFO");
 		for (uint16_t i = 0; i < len; ++i) {writeRegister(REG_FIFO, data[i]);}
 		writeRegister(REG_PAYLOAD_LENGTH, len);
 
@@ -371,38 +370,43 @@ public:
 		//if ((async) && (_onTxDone)) writeRegister(REG_DIO_MAPPING_1, 0x40); // DIO0 => TXDONE
 
 		// put in TX mode
-		debugMod(NAME, "starting TX");
+		//debugMod(NAME, "starting TX");
 		writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_TX);
 
 		if (!async) {
-			debugMod(NAME, "waiting");
+			//debugMod(NAME, "waiting");
 			while ((readRegister(REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK) == 0) {yield();}	// wait for TX done
 			writeRegister(REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);								// clear IRQ TX-done flag
-			debugMod(NAME, "done");
+			debugMod(NAME, "tx done");
 		}
 		
 		return len;
 		
 	}
 	
-	/** switch to RX-mode. either for a single frame or permanent */
-	void setRX(bool single) {
-		
-		// reset FIFO address
-		writeRegister(REG_FIFO_ADDR_PTR, 0);
-
-		// put in single RX mode
-		if (single) {
-			writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_RX_SINGLE);
-		} else {
-			writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_RX_CONTINUOUS);
-		}
+	/** blocking wait for TX to finish */
+	void waitTxComplete() {
 		
 	}
 	
+	/** switch to RX mode, but only for a single packet */
+	void rxSingle() {
+		enableRX(true);
+	}
+	
+	/** switch to RX mode, continuously */
+	void rxContinuous() {
+		enableRX(false);
+	}
+	
 
 	
-	/** fetch one received packet, if any is available. requires setRX(..) beforehand to actually receive something! */
+
+	
+	/**
+	 * fetch one received packet, if any is available.
+	 * requires rxSingle()/rxContinuous() beforehand to actually receive something!!!
+	 */
 	int read(uint8_t* dst, PacketDetails* det) {
 		
 		uint8_t irqFlags = readRegister(REG_IRQ_FLAGS);
@@ -428,8 +432,8 @@ public:
 
 			// read the details?
 			if (det) {
-				det->rssi =	(readRegister(REG_PKT_RSSI_VALUE) - (curFreq < 868E6 ? 164 : 157));
-				det->snr =	((int8_t)readRegister(REG_PKT_SNR_VALUE)) * 0.25f;
+				det->rssi =	(readRegister(REG_PKT_RSSI_VALUE) - (curFreq < 868E6 ? 164 : 157));	// can be smaller than -128 !! -> overflow -> use getter method
+				det->snr4 =	((int8_t)readRegister(REG_PKT_SNR_VALUE));							// SNR*4 (must be scaled by 0.25) -> use getter method
 			}
 
 			// put in standby mode
@@ -455,19 +459,40 @@ private:
 		usleep(5000);
 	}
 	
+	/**
+	 * configure explicit header mode.
+	 * TX: the SX1276 appends an automatically created header in front of every packet
+	 * RX: the SX1276 expects and automatically reads the header in front of every received packet
+	 * Note: the header contains the packet's length, and the FEC (codingRate) for the content
+	 * the header itself always has a coding rate of 8/4(?)
+	 */ 
 	void explicitHeaderMode() {
 		writeRegister(REG_MODEM_CONFIG_1, readRegister(REG_MODEM_CONFIG_1) & 0xfe);
 	}
 
-	void implicitHeaderMode() {
-		writeRegister(REG_MODEM_CONFIG_1, readRegister(REG_MODEM_CONFIG_1) | 0x01);
+//	void implicitHeaderMode() {
+//		writeRegister(REG_MODEM_CONFIG_1, readRegister(REG_MODEM_CONFIG_1) | 0x01);
+//	}
+
+
+
+	/** switch to RX-mode. either for a single frame or permanent */
+	void enableRX(bool single) {
+		
+		debugMod1(NAME, "rx(single: %d)", single);
+		
+		// reset FIFO address
+		writeRegister(REG_FIFO_ADDR_PTR, 0);
+
+		// put in single RX mode
+		if (single) {
+			writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_RX_SINGLE);
+		} else {
+			writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_RX_CONTINUOUS);
+		}
+		
 	}
 
-//	uint8_t getMode() {
-//		const uint8_t mode = readRegister(REG_OP_MODE);
-//		debugMod1(NAME, "mode: %d", mode);
-//		return mode;
-//	}
 
 	/** set the RF frequency to use (in Hz) */
 	void setFrequency(uint32_t hz) {