// **********************************************************************************
// Driver definition for HopeRF RFM69W/RFM69HW/RFM69CW/RFM69HCW, Semtech SX1231/1231H
// **********************************************************************************
// Copyright Felix Rusu (2014), felix@lowpowerlab.com
// http://lowpowerlab.com/
// **********************************************************************************
// License
// **********************************************************************************
// This program is free software; you can redistribute it
// and/or modify it under the terms of the GNU General
// Public License as published by the Free Software
// Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will
// be useful, but WITHOUT ANY WARRANTY; without even the
// implied warranty of MERCHANTABILITY or FITNESS FOR A
// PARTICULAR PURPOSE. See the GNU General Public
// License for more details.
//
// You should have received a copy of the GNU General
// Public License along with this program.
// If not, see <http://www.gnu.org/licenses/>.
//
// Licence can be viewed at
// http://www.gnu.org/licenses/gpl-3.0.txt
//
// Please maintain this license information along with authorship
// and copyright notices in any redistribution of this code
// **********************************************************************************
#include "RFM69_old.h"
#include "RFM69registers_old.h"

volatile uint8_t RFM69::DATA[RFM69_MAX_DATA_LEN];
volatile uint8_t RFM69::_mode;        // current transceiver state
volatile uint8_t RFM69::DATALEN;
volatile uint8_t RFM69::SENDERID;
volatile uint8_t RFM69::TARGETID;     // should match _address
volatile uint8_t RFM69::PAYLOADLEN;
volatile uint8_t RFM69::ACK_REQUESTED;
volatile uint8_t
RFM69::ACK_RECEIVED; // should be polled immediately after sending a packet with ACK request
volatile int16_t
RFM69::RSSI;          // most accurate RSSI during reception (closest to the reception)
RFM69* RFM69::selfPointer;

bool RFM69::initialize(uint8_t freqBand, uint8_t nodeID, uint8_t networkID)
{
	//powerUp();
	//reset();
	const uint8_t CONFIG[][2] = {
		/* 0x01 */ { REG_OPMODE, RF_OPMODE_SEQUENCER_ON | RF_OPMODE_LISTEN_OFF | RF_OPMODE_STANDBY },
		/* 0x02 */ { REG_DATAMODUL, RF_DATAMODUL_DATAMODE_PACKET | RF_DATAMODUL_MODULATIONTYPE_FSK | RF_DATAMODUL_MODULATIONSHAPING_00 }, // no shaping
		/* 0x03 */ { REG_BITRATEMSB, RF_BITRATEMSB_55555}, // default: 4.8 KBPS
		/* 0x04 */ { REG_BITRATELSB, RF_BITRATELSB_55555},
		/* 0x05 */ { REG_FDEVMSB, RF_FDEVMSB_50000}, // default: 5KHz, (FDEV + BitRate / 2 <= 500KHz)
		/* 0x06 */ { REG_FDEVLSB, RF_FDEVLSB_50000},

		/* 0x07 */ { REG_FRFMSB, (uint8_t) (freqBand==RFM69_315MHZ ? RF_FRFMSB_315 : (freqBand==RFM69_433MHZ ? RF_FRFMSB_433 : (freqBand==RFM69_868MHZ ? RF_FRFMSB_868 : RF_FRFMSB_915))) },
		/* 0x08 */ { REG_FRFMID, (uint8_t) (freqBand==RFM69_315MHZ ? RF_FRFMID_315 : (freqBand==RFM69_433MHZ ? RF_FRFMID_433 : (freqBand==RFM69_868MHZ ? RF_FRFMID_868 : RF_FRFMID_915))) },
		/* 0x09 */ { REG_FRFLSB, (uint8_t) (freqBand==RFM69_315MHZ ? RF_FRFLSB_315 : (freqBand==RFM69_433MHZ ? RF_FRFLSB_433 : (freqBand==RFM69_868MHZ ? RF_FRFLSB_868 : RF_FRFLSB_915))) },

		// looks like PA1 and PA2 are not implemented on RFM69W, hence the max output power is 13dBm
		// +17dBm and +20dBm are possible on RFM69HW
		// +13dBm formula: Pout = -18 + OutputPower (with PA0 or PA1**)
		// +17dBm formula: Pout = -14 + OutputPower (with PA1 and PA2)**
		// +20dBm formula: Pout = -11 + OutputPower (with PA1 and PA2)** and high power PA settings (section 3.3.7 in datasheet)
		///* 0x11 */ { REG_PALEVEL, RF_PALEVEL_PA0_ON | RF_PALEVEL_PA1_OFF | RF_PALEVEL_PA2_OFF | RF_PALEVEL_OUTPUTPOWER_11111},
		///* 0x13 */ { REG_OCP, RF_OCP_ON | RF_OCP_TRIM_95 }, // over current protection (default is 95mA)

		// RXBW defaults are { REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_24 | RF_RXBW_EXP_5} (RxBw: 10.4KHz)
		/* 0x19 */ { REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_16 | RF_RXBW_EXP_2 }, // (BitRate < 2 * RxBw)
		//for BR-19200: /* 0x19 */ { REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_24 | RF_RXBW_EXP_3 },
		/* 0x25 */ { REG_DIOMAPPING1, RF_DIOMAPPING1_DIO0_01 }, // DIO0 is the only IRQ we're using
		/* 0x26 */ { REG_DIOMAPPING2, RF_DIOMAPPING2_CLKOUT_OFF }, // DIO5 ClkOut disable for power saving
		/* 0x28 */ { REG_IRQFLAGS2, RF_IRQFLAGS2_FIFOOVERRUN }, // writing to this bit ensures that the FIFO & status flags are reset
		/* 0x29 */ { REG_RSSITHRESH, 220 }, // must be set to dBm = (-Sensitivity / 2), default is 0xE4 = 228 so -114dBm
		///* 0x2D */ { REG_PREAMBLELSB, RF_PREAMBLESIZE_LSB_VALUE } // default 3 preamble bytes 0xAAAAAA
		/* 0x2E */ { REG_SYNCCONFIG, RF_SYNC_ON | RF_SYNC_FIFOFILL_AUTO | RF_SYNC_SIZE_2 | RF_SYNC_TOL_0 },
		/* 0x2F */ { REG_SYNCVALUE1, 0x2D },      // attempt to make this compatible with sync1 byte of RFM12B lib
		/* 0x30 */ { REG_SYNCVALUE2, networkID }, // NETWORK ID
		/* 0x37 */ { REG_PACKETCONFIG1, RF_PACKET1_FORMAT_VARIABLE | RF_PACKET1_DCFREE_OFF | RF_PACKET1_CRC_ON | RF_PACKET1_CRCAUTOCLEAR_ON | RF_PACKET1_ADRSFILTERING_OFF },
		/* 0x38 */ { REG_PAYLOADLENGTH, 66 }, // in variable length mode: the max frame size, not used in TX
		///* 0x39 */ { REG_NODEADRS, nodeID }, // turned off because we're not using address filtering
		/* 0x3C */ { REG_FIFOTHRESH, RF_FIFOTHRESH_TXSTART_FIFONOTEMPTY | RF_FIFOTHRESH_VALUE }, // TX on FIFO not empty
		/* 0x3D */ { REG_PACKETCONFIG2, RF_PACKET2_RXRESTARTDELAY_2BITS | RF_PACKET2_AUTORXRESTART_ON | RF_PACKET2_AES_OFF }, // RXRESTARTDELAY must match transmitter PA ramp-down time (bitrate dependent)
		//for BR-19200: /* 0x3D */ { REG_PACKETCONFIG2, RF_PACKET2_RXRESTARTDELAY_NONE | RF_PACKET2_AUTORXRESTART_ON | RF_PACKET2_AES_OFF }, // RXRESTARTDELAY must match transmitter PA ramp-down time (bitrate dependent)
		/* 0x6F */ { REG_TESTDAGC, RF_DAGC_IMPROVED_LOWBETA0 }, // run DAGC continuously in RX mode for Fading Margin Improvement, recommended default for AfcLowBetaOn=0
		{255, 0}
	};

	hwDigitalWrite(_slaveSelectPin, HIGH);
	hwPinMode(_slaveSelectPin, OUTPUT);
	hwPinMode(_interruptPin, INPUT);

	RFM69_SPI.begin();
	unsigned long start = hwMillis();
	const uint8_t timeout = 50;
	do {
		writeReg(REG_SYNCVALUE1, 0xAA);
		doYield();
	} while (readReg(REG_SYNCVALUE1) != 0xAA && hwMillis()-start < timeout);
	if (hwMillis() - start >= timeout) {
		// timeout: checking wiring or replace module
		return false;
	}
	start = hwMillis();
	do {
		writeReg(REG_SYNCVALUE1, 0x55);
		doYield();
	} while (readReg(REG_SYNCVALUE1) != 0x55 && hwMillis()-start < timeout);
	if (hwMillis() - start >= timeout) {
		// timeout: checking wiring or replace module
		return false;
	}
	for (uint8_t i = 0; CONFIG[i][0] != 255; i++) {
		writeReg(CONFIG[i][0], CONFIG[i][1]);
	}

	// Encryption is persistent between resets and can trip you up during debugging.
	// Disable it during initialization so we always start from a known state.
	encrypt(0);

	setHighPower(_isRFM69HW); // called regardless if it's a RFM69W or RFM69HW
	setMode(RFM69_MODE_STANDBY);
	start = hwMillis();
	while (((readReg(REG_IRQFLAGS1) & RF_IRQFLAGS1_MODEREADY) == 0x00) && hwMillis()-start < timeout) {
		doYield();
	} // wait for ModeReady
	if (hwMillis()-start >= timeout) {
		return false;
	}

	//RFM69_SPI.usingInterrupt(_interruptNum);
	attachInterrupt(_interruptNum, RFM69::isr0, RISING);

	selfPointer = this;
	_address = nodeID;
	return true;
}

// return the frequency (in Hz)
uint32_t RFM69::getFrequency()
{
	return RFM69_FSTEP * (((uint32_t) readReg(REG_FRFMSB) << 16) + ((uint16_t) readReg(
	                          REG_FRFMID) << 8) + readReg(REG_FRFLSB));
}

// set the frequency (in Hz)
void RFM69::setFrequency(uint32_t freqHz)
{
	uint8_t oldMode = _mode;
	if (oldMode == RFM69_MODE_TX) {
		setMode(RFM69_MODE_RX);
	}
	freqHz /= RFM69_FSTEP; // divide down by FSTEP to get FRF
	writeReg(REG_FRFMSB, freqHz >> 16);
	writeReg(REG_FRFMID, freqHz >> 8);
	writeReg(REG_FRFLSB, freqHz);
	if (oldMode == RFM69_MODE_RX) {
		setMode(RFM69_MODE_SYNTH);
	}
	setMode(oldMode);
}

void RFM69::setMode(uint8_t newMode)
{
	if (newMode == _mode) {
		return;
	}

	const uint8_t currentOPMODE = readReg(REG_OPMODE) & 0xE3;

	switch (newMode) {
	case RFM69_MODE_TX:
		writeReg(REG_OPMODE, currentOPMODE | RF_OPMODE_TRANSMITTER);
		if (_isRFM69HW) {
			setHighPowerRegs(true);
		}
		break;
	case RFM69_MODE_RX:
		writeReg(REG_OPMODE, currentOPMODE | RF_OPMODE_RECEIVER);
		if (_isRFM69HW) {
			setHighPowerRegs(false);
		}
		break;
	case RFM69_MODE_SYNTH:
		writeReg(REG_OPMODE, currentOPMODE | RF_OPMODE_SYNTHESIZER);
		break;
	case RFM69_MODE_STANDBY:
		writeReg(REG_OPMODE, currentOPMODE | RF_OPMODE_STANDBY);
		break;
	case RFM69_MODE_SLEEP:
		writeReg(REG_OPMODE, currentOPMODE | RF_OPMODE_SLEEP);
		break;
	default:
		return;
	}

	// we are using packet mode, so this check is not really needed
	// but waiting for mode ready is necessary when going from sleep because the FIFO may not be immediately available from previous mode
	while (_mode == RFM69_MODE_SLEEP &&
	        (readReg(REG_IRQFLAGS1) & RF_IRQFLAGS1_MODEREADY) == 0x00); // wait for ModeReady

	_mode = newMode;
}

//put transceiver in sleep mode to save battery - to wake or resume receiving just call receiveDone()
void RFM69::sleep(void)
{
	setMode(RFM69_MODE_SLEEP);
}

void RFM69::standBy(void)
{
	setMode(RFM69_MODE_STANDBY);
}
void RFM69::powerDown(void)
{
#if defined(MY_RFM69_POWER_PIN)
	hwDigitalWrite(MY_RFM69_POWER_PIN, LOW);
#endif
}
void RFM69::powerUp(void)
{
#if defined(MY_RFM69_POWER_PIN)
	hwDigitalWrite(MY_RFM69_POWER_PIN, HIGH);
	delay(RFM69_POWERUP_DELAY_MS);
#endif
}
void RFM69::reset(void)
{
	// reset radio if RESET pin is defined
#ifdef MY_RFM69_RST_PIN
	hwPinMode(MY_RFM69_RST_PIN, OUTPUT);
	hwDigitalWrite(MY_RFM69_RST_PIN, HIGH);
	// 100uS
	delayMicroseconds(100);
	hwDigitalWrite(MY_RFM69_RST_PIN, LOW);
	// wait until chip ready
	delay(5);
#endif
}

bool RFM69::sanityCheck(void)
{
	bool result = true;
	// check Bitrate
	result &= readReg(REG_BITRATEMSB) == RF_BITRATEMSB_55555;
	result &= readReg(REG_BITRATELSB) == RF_BITRATELSB_55555;
	// default: 5KHz, (FDEV + BitRate / 2 <= 500KHz)
	result &= readReg(REG_FDEVMSB) == RF_FDEVMSB_50000;
	result &= readReg(REG_FDEVLSB) == RF_FDEVLSB_50000;
	/*
	// Check radio frequency band
	result &= readReg(REG_FRFMSB) == (uint8_t)(MY_RFM69_FREQUENCY == RFM69_315MHZ ? RF_FRFMSB_315 : (MY_RFM69_FREQUENCY == RFM69_433MHZ ? RF_FRFMSB_433 : (MY_RFM69_FREQUENCY == RFM69_868MHZ ? RF_FRFMSB_868 : RF_FRFMSB_915)));
	result &= readReg(REG_FRFMID) == (uint8_t)(MY_RFM69_FREQUENCY == RFM69_315MHZ ? RF_FRFMID_315 : (MY_RFM69_FREQUENCY == RFM69_433MHZ ? RF_FRFMID_433 : (MY_RFM69_FREQUENCY == RFM69_868MHZ ? RF_FRFMID_868 : RF_FRFMID_915)));
	result &= readReg(REG_FRFLSB) == (uint8_t)(MY_RFM69_FREQUENCY == RFM69_315MHZ ? RF_FRFLSB_315 : (MY_RFM69_FREQUENCY == RFM69_433MHZ ? RF_FRFLSB_433 : (MY_RFM69_FREQUENCY == RFM69_868MHZ ? RF_FRFLSB_868 : RF_FRFLSB_915)));
	*/
	return result;
}

//set this node's address
void RFM69::setAddress(uint8_t addr)
{
	_address = addr;
	writeReg(REG_NODEADRS, _address);
}

//set this node's network id
void RFM69::setNetwork(uint8_t networkID)
{
	writeReg(REG_SYNCVALUE2, networkID);
}

// set *transmit/TX* output power: 0=min, 31=max
// this results in a "weaker" transmitted signal, and directly results in a lower RSSI at the receiver
// the power configurations are explained in the SX1231H datasheet (Table 10 on p21; RegPaLevel p66): http://www.semtech.com/images/datasheet/sx1231h.pdf
// valid powerLevel parameter values are 0-31 and result in a directly proportional effect on the output/transmission power
// this function implements 2 modes as follows:
//       - for RFM69W the range is from 0-31 [-18dBm to 13dBm] (PA0 only on RFIO pin)
//       - for RFM69HW the range is from 0-31 [5dBm to 20dBm]  (PA1 & PA2 on PA_BOOST pin & high Power PA settings - see section 3.3.7 in datasheet, p22)
void RFM69::setPowerLevel(uint8_t powerLevel)
{
	_powerLevel = (powerLevel > 31 ? 31 : powerLevel);
	if (_isRFM69HW) {
		_powerLevel /= 2;
	}
	writeReg(REG_PALEVEL, (readReg(REG_PALEVEL) & 0xE0) | _powerLevel);
}

bool RFM69::canSend()
{
	if (_mode == RFM69_MODE_RX && PAYLOADLEN == 0 &&
	        readRSSI() < CSMA_LIMIT) { // if signal stronger than -100dBm is detected assume channel activity
		setMode(RFM69_MODE_STANDBY);
		return true;
	}
	return false;
}

void RFM69::send(uint8_t toAddress, const void* buffer, uint8_t bufferSize, bool requestACK)
{
	writeReg(REG_PACKETCONFIG2, (readReg(REG_PACKETCONFIG2) & 0xFB) |
	         RF_PACKET2_RXRESTART); // avoid RX deadlocks
	uint32_t now = hwMillis();
	while (!canSend() && hwMillis() - now < RFM69_CSMA_LIMIT_MS) {
		receiveDone();
	}
	sendFrame(toAddress, buffer, bufferSize, requestACK, false);
}

// to increase the chance of getting a packet across, call this function instead of send
// and it handles all the ACK requesting/retrying for you :)
// The only twist is that you have to manually listen to ACK requests on the other side and send back the ACKs
// The reason for the semi-automaton is that the lib is interrupt driven and
// requires user action to read the received data and decide what to do with it
// replies usually take only 5..8ms at 50kbps@915MHz
bool RFM69::sendWithRetry(uint8_t toAddress, const void* buffer, uint8_t bufferSize,
                          uint8_t retries, uint8_t retryWaitTime)
{
	for (uint8_t i = 0; i <= retries; i++) {
		send(toAddress, buffer, bufferSize, true);
		uint32_t sentTime = hwMillis();
		while (hwMillis() - sentTime < retryWaitTime) {
			if (ACKReceived(toAddress)) {
				return true;
			}
		}
		//Serial.print(" RETRY#"); Serial.println(i + 1);
	}
	return false;
}

// should be polled immediately after sending a packet with ACK request
bool RFM69::ACKReceived(uint8_t fromNodeID)
{
	if (receiveDone()) {
		return (SENDERID == fromNodeID || fromNodeID == RFM69_BROADCAST_ADDR) && ACK_RECEIVED;
	}
	return false;
}

// check whether an ACK was requested in the last received packet (non-broadcasted packet)
bool RFM69::ACKRequested()
{
	return ACK_REQUESTED && (TARGETID != RFM69_BROADCAST_ADDR);
}

// should be called immediately after reception in case sender wants ACK
void RFM69::sendACK(const void* buffer, uint8_t bufferSize)
{
	ACK_REQUESTED =
	    0;   // TWS added to make sure we don't end up in a timing race and infinite loop sending Acks
	uint8_t sender = SENDERID;
	int16_t _RSSI = RSSI; // save payload received RSSI value
	writeReg(REG_PACKETCONFIG2, (readReg(REG_PACKETCONFIG2) & 0xFB) |
	         RF_PACKET2_RXRESTART); // avoid RX deadlocks
	uint32_t now = hwMillis();
	while (!canSend() && hwMillis() - now < RFM69_CSMA_LIMIT_MS) {
		receiveDone();
		doYield();
	}
	SENDERID = sender;    // TWS: Restore SenderID after it gets wiped out by receiveDone()
	sendFrame(sender, buffer, bufferSize, false, true);
	RSSI = _RSSI; // restore payload RSSI
}

void RFM69::interruptHook(uint8_t CTLbyte)
{
	(void)CTLbyte;
};

// internal function
void RFM69::sendFrame(uint8_t toAddress, const void* buffer, uint8_t bufferSize, bool requestACK,
                      bool sendACK)
{
	setMode(RFM69_MODE_STANDBY); // turn off receiver to prevent reception while filling fifo
	while ((readReg(REG_IRQFLAGS1) & RF_IRQFLAGS1_MODEREADY) == 0x00) {} // wait for ModeReady
	writeReg(REG_DIOMAPPING1, RF_DIOMAPPING1_DIO0_00); // DIO0 is "Packet Sent"
	if (bufferSize > RFM69_MAX_DATA_LEN) {
		bufferSize = RFM69_MAX_DATA_LEN;
	}

	// control byte
	uint8_t CTLbyte = 0x00;
	if (sendACK) {
		CTLbyte = RFM69_CTL_SENDACK;
	} else if (requestACK) {
		CTLbyte = RFM69_CTL_REQACK;
	}

	// write to FIFO
	select();
	RFM69_SPI.transfer(REG_FIFO | 0x80);
	RFM69_SPI.transfer(bufferSize + 3);
	RFM69_SPI.transfer(toAddress);
	RFM69_SPI.transfer(_address);
	RFM69_SPI.transfer(CTLbyte);

	for (uint8_t i = 0; i < bufferSize; i++) {
		RFM69_SPI.transfer(((uint8_t *)buffer)[i]);
	}
	unselect();

	// no need to wait for transmit mode to be ready since its handled by the radio
	setMode(RFM69_MODE_TX);
	uint32_t txStart = hwMillis();
	while (hwDigitalRead(_interruptPin) == 0 &&
	        hwMillis() - txStart <
	        RFM69_TX_LIMIT_MS) {} // wait for DIO0 to turn HIGH signalling transmission finish
	//while (readReg(REG_IRQFLAGS2) & RF_IRQFLAGS2_PACKETSENT == 0x00); // wait for ModeReady
	setMode(RFM69_MODE_STANDBY);
}

// internal function - interrupt gets called when a packet is received
void IRQ_HANDLER_ATTR RFM69::interruptHandler()
{
	//hwPinMode(4, OUTPUT);
	//hwDigitalWrite(4, 1);
	if (_mode == RFM69_MODE_RX && (readReg(REG_IRQFLAGS2) & RF_IRQFLAGS2_PAYLOADREADY)) {
		//RSSI = readRSSI();
		setMode(RFM69_MODE_STANDBY);
		select();
		RFM69_SPI.transfer(REG_FIFO & 0x7F);
		PAYLOADLEN = RFM69_SPI.transfer(0);
		PAYLOADLEN = PAYLOADLEN > 66 ? 66 : PAYLOADLEN; // precaution
		TARGETID = RFM69_SPI.transfer(0);
		if(!(_promiscuousMode || TARGETID == _address ||
		        TARGETID ==
		        RFM69_BROADCAST_ADDR) // match this node's address, or broadcast address or anything in promiscuous mode
		        || PAYLOADLEN <
		        3) { // address situation could receive packets that are malformed and don't fit this libraries extra fields
			PAYLOADLEN = 0;
			unselect();
			receiveBegin();
			//hwDigitalWrite(4, 0);
			return;
		}

		DATALEN = PAYLOADLEN - 3;
		SENDERID = RFM69_SPI.transfer(0);
		uint8_t CTLbyte = RFM69_SPI.transfer(0);

		ACK_RECEIVED = CTLbyte & RFM69_CTL_SENDACK; // extract ACK-received flag
		ACK_REQUESTED = CTLbyte & RFM69_CTL_REQACK; // extract ACK-requested flag

		interruptHook(CTLbyte);     // TWS: hook to derived class interrupt function

		for (uint8_t i = 0; i < DATALEN; i++) {
			DATA[i] = RFM69_SPI.transfer(0);
		}
		if (DATALEN < RFM69_MAX_DATA_LEN) {
			DATA[DATALEN] = 0; // add null at end of string
		}
		unselect();
		setMode(RFM69_MODE_RX);
	}
	RSSI = readRSSI();
	//hwDigitalWrite(4, 0);
}

// internal function
void IRQ_HANDLER_ATTR RFM69::isr0()
{
	selfPointer->interruptHandler();
}

// internal function
void RFM69::receiveBegin()
{
	DATALEN = 0;
	SENDERID = 0;
	TARGETID = 0;
	PAYLOADLEN = 0;
	ACK_REQUESTED = 0;
	ACK_RECEIVED = 0;
	RSSI = 0;
	if (readReg(REG_IRQFLAGS2) & RF_IRQFLAGS2_PAYLOADREADY) {
		writeReg(REG_PACKETCONFIG2, (readReg(REG_PACKETCONFIG2) & 0xFB) |
		         RF_PACKET2_RXRESTART); // avoid RX deadlocks
	}
	writeReg(REG_DIOMAPPING1, RF_DIOMAPPING1_DIO0_01); // set DIO0 to "PAYLOADREADY" in receive mode
	setMode(RFM69_MODE_RX);
}

// checks if a packet was received and/or puts transceiver in receive (ie RX or listen) mode
bool RFM69::receiveDone()
{
	//ATOMIC_BLOCK(ATOMIC_FORCEON)
	//{
	noInterrupts(); // re-enabled in unselect() via setMode() or via receiveBegin()
	if (_mode == RFM69_MODE_RX && PAYLOADLEN > 0) {
		setMode(RFM69_MODE_STANDBY); // enables interrupts
		return true;
	} else if (_mode == RFM69_MODE_RX) { // already in RX no payload yet
		interrupts(); // explicitly re-enable interrupts
		return false;
	}
	receiveBegin();
	return false;
	//}
}

// To enable encryption: radio.encrypt("ABCDEFGHIJKLMNOP");
// To disable encryption: radio.encrypt(null) or radio.encrypt(0)
// KEY HAS TO BE 16 bytes !!!
void RFM69::encrypt(const char* key)
{
	setMode(RFM69_MODE_STANDBY);
	if (key != 0) {
		select();
		RFM69_SPI.transfer(REG_AESKEY1 | 0x80);
		for (uint8_t i = 0; i < 16; i++) {
			RFM69_SPI.transfer(key[i]);
		}
		unselect();
	}
	writeReg(REG_PACKETCONFIG2, (readReg(REG_PACKETCONFIG2) & 0xFE) | (key ? 1 : 0));
}

// get the received signal strength indicator (RSSI)
int16_t RFM69::readRSSI(bool forceTrigger)
{
	int16_t rssi = 0;
	if (forceTrigger) {
		// RSSI trigger not needed if DAGC is in continuous mode
		writeReg(REG_RSSICONFIG, RF_RSSI_START);
		while ((readReg(REG_RSSICONFIG) & RF_RSSI_DONE) == 0x00) {} // wait for RSSI_Ready
	}
	rssi = -readReg(REG_RSSIVALUE);
	rssi >>= 1;
	return rssi;
}

uint8_t RFM69::readReg(uint8_t addr)
{
	select();
	RFM69_SPI.transfer(addr & 0x7F);
	uint8_t regval = RFM69_SPI.transfer(0);
	unselect();
	return regval;
}

void RFM69::writeReg(uint8_t addr, uint8_t value)
{
	select();
	RFM69_SPI.transfer(addr | 0x80);
	RFM69_SPI.transfer(value);
	unselect();
}

// select the RFM69 transceiver (save SPI settings, set CS low)
void RFM69::select()
{
	noInterrupts();
#if defined (SPCR) && defined (SPSR)
	// save current SPI settings
	_SPCR = SPCR;
	_SPSR = SPSR;
#endif
	// set RFM69 SPI settings
	RFM69_SPI.setDataMode(SPI_MODE0);
	RFM69_SPI.setBitOrder(MSBFIRST);
	RFM69_SPI.setClockDivider(RFM69_CLOCK_DIV);
	hwDigitalWrite(_slaveSelectPin, LOW);
}

// unselect the RFM69 transceiver (set CS high, restore SPI settings)
void RFM69::unselect()
{
	hwDigitalWrite(_slaveSelectPin, HIGH);
	// restore SPI settings to what they were before talking to RFM69
#if defined (SPCR) && defined (SPSR)
	SPCR = _SPCR;
	SPSR = _SPSR;
#endif
	interrupts();
}

// true  = disable filtering to capture all frames on network
// false = enable node/broadcast filtering to capture only frames sent to this/broadcast address
void RFM69::promiscuous(bool onOff)
{
	_promiscuousMode = onOff;
	//writeReg(REG_PACKETCONFIG1, (readReg(REG_PACKETCONFIG1) & 0xF9) | (onOff ? RF_PACKET1_ADRSFILTERING_OFF : RF_PACKET1_ADRSFILTERING_NODEBROADCAST));
}

// for RFM69HW only: you must call setHighPower(true) after initialize() or else transmission won't work
void RFM69::setHighPower(bool onOff)
{
	_isRFM69HW = onOff;
	writeReg(REG_OCP, _isRFM69HW ? RF_OCP_OFF : RF_OCP_ON);
	if (_isRFM69HW) { // turning ON
		writeReg(REG_PALEVEL, (readReg(REG_PALEVEL) & 0x1F) | RF_PALEVEL_PA1_ON |
		         RF_PALEVEL_PA2_ON); // enable P1 & P2 amplifier stages
	} else {
		writeReg(REG_PALEVEL, RF_PALEVEL_PA0_ON | RF_PALEVEL_PA1_OFF | RF_PALEVEL_PA2_OFF |
		         _powerLevel); // enable P0 only
	}
}

// internal function
void RFM69::setHighPowerRegs(bool onOff)
{
	writeReg(REG_TESTPA1, onOff ? 0x5D : 0x55);
	writeReg(REG_TESTPA2, onOff ? 0x7C : 0x70);
}

// set the slave select (CS) pin
void RFM69::setCS(uint8_t newSPISlaveSelect)
{
	_slaveSelectPin = newSPISlaveSelect;
	hwDigitalWrite(_slaveSelectPin, HIGH);
	hwPinMode(_slaveSelectPin, OUTPUT);
}

//for debugging
#define REGISTER_DETAIL 0
#if REGISTER_DETAIL
// SERIAL PRINT
// replace Serial.print("string") with SerialPrint("string")
#define SerialPrint(x) SerialPrint_P(PSTR(x))
void SerialWrite ( uint8_t c )
{
	Serial.write ( c );
}

void SerialPrint_P(PGM_P str, void (*f)(uint8_t) = SerialWrite )
{
	for (uint8_t c; (c = pgm_read_byte(str)); str++) {
		(*f)(c);
	}
}
#endif

void RFM69::readAllRegs()
{
#if REGISTER_DETAIL
	int capVal;

	//... State Variables for intelligent decoding
	uint8_t modeFSK = 0;
	int bitRate = 0;
	int freqDev = 0;
	long freqCenter = 0;
#endif

	Serial.println("Address - HEX - BIN");
	for (uint8_t regAddr = 1; regAddr <= 0x4F; regAddr++) {
		select();
		RFM69_SPI.transfer(regAddr & 0x7F); // send address + r/w bit
		uint8_t regVal = RFM69_SPI.transfer(0);
		unselect();

		Serial.print(regAddr, HEX);
		Serial.print(" - ");
		Serial.print(regVal,HEX);
		Serial.print(" - ");
		Serial.println(regVal,BIN);

#if REGISTER_DETAIL
		switch ( regAddr ) {
		case 0x1 : {
			SerialPrint ( "Controls the automatic Sequencer ( see section 4.2 )\nSequencerOff : " );
			if ( 0x80 & regVal ) {
				SerialPrint ( "1 -> Mode is forced by the user\n" );
			} else {
				SerialPrint ( "0 -> Operating mode as selected with Mode bits in RegOpMode is automatically reached with the Sequencer\n" );
			}

			SerialPrint( "\nEnables Listen mode, should be enabled whilst in Standby mode:\nListenOn : " );
			if ( 0x40 & regVal ) {
				SerialPrint ( "1 -> On\n" );
			} else {
				SerialPrint ( "0 -> Off ( see section 4.3)\n" );
			}

			SerialPrint( "\nAborts Listen mode when set together with ListenOn=0 See section 4.3.4 for details (Always reads 0.)\n" );
			if ( 0x20 & regVal ) {
				SerialPrint ( "ERROR - ListenAbort should NEVER return 1 this is a write only register\n" );
			}

			SerialPrint("\nTransceiver's operating modes:\nMode : ");
			capVal = (regVal >> 2) & 0x7;
			if ( capVal == 0b000 ) {
				SerialPrint ( "000 -> Sleep mode (SLEEP)\n" );
			} else if ( capVal = 0b001 ) {
				SerialPrint ( "001 -> Standby mode (STDBY)\n" );
			} else if ( capVal = 0b010 ) {
				SerialPrint ( "010 -> Frequency Synthesizer mode (FS)\n" );
			} else if ( capVal = 0b011 ) {
				SerialPrint ( "011 -> Transmitter mode (TX)\n" );
			} else if ( capVal = 0b100 ) {
				SerialPrint ( "100 -> Receiver Mode (RX)\n" );
			} else {
				Serial.print( capVal, BIN );
				SerialPrint ( " -> RESERVED\n" );
			}
			SerialPrint ( "\n" );
			break;
		}

		case 0x2 : {

			SerialPrint("Data Processing mode:\nDataMode : ");
			capVal = (regVal >> 5) & 0x3;
			if ( capVal == 0b00 ) {
				SerialPrint ( "00 -> Packet mode\n" );
			} else if ( capVal == 0b01 ) {
				SerialPrint ( "01 -> reserved\n" );
			} else if ( capVal == 0b10 ) {
				SerialPrint ( "10 -> Continuous mode with bit synchronizer\n" );
			} else if ( capVal == 0b11 ) {
				SerialPrint ( "11 -> Continuous mode without bit synchronizer\n" );
			}

			SerialPrint("\nModulation scheme:\nModulation Type : ");
			capVal = (regVal >> 3) & 0x3;
			if ( capVal == 0b00 ) {
				SerialPrint ( "00 -> FSK\n" );
				modeFSK = 1;
			} else if ( capVal == 0b01 ) {
				SerialPrint ( "01 -> OOK\n" );
			} else if ( capVal == 0b10 ) {
				SerialPrint ( "10 -> reserved\n" );
			} else if ( capVal == 0b11 ) {
				SerialPrint ( "11 -> reserved\n" );
			}

			SerialPrint("\nData shaping: ");
			if ( modeFSK ) {
				SerialPrint( "in FSK:\n" );
			} else {
				SerialPrint( "in OOK:\n" );
			}
			SerialPrint ("ModulationShaping : ");
			capVal = regVal & 0x3;
			if ( modeFSK ) {
				if ( capVal == 0b00 ) {
					SerialPrint ( "00 -> no shaping\n" );
				} else if ( capVal == 0b01 ) {
					SerialPrint ( "01 -> Gaussian filter, BT = 1.0\n" );
				} else if ( capVal == 0b10 ) {
					SerialPrint ( "10 -> Gaussian filter, BT = 0.5\n" );
				} else if ( capVal == 0b11 ) {
					SerialPrint ( "11 -> Gaussian filter, BT = 0.3\n" );
				}
			} else {
				if ( capVal == 0b00 ) {
					SerialPrint ( "00 -> no shaping\n" );
				} else if ( capVal == 0b01 ) {
					SerialPrint ( "01 -> filtering with f(cutoff) = BR\n" );
				} else if ( capVal == 0b10 ) {
					SerialPrint ( "10 -> filtering with f(cutoff) = 2*BR\n" );
				} else if ( capVal == 0b11 ) {
					SerialPrint ( "ERROR - 11 is reserved\n" );
				}
			}

			SerialPrint ( "\n" );
			break;
		}

		case 0x3 : {
			bitRate = (regVal << 8);
			break;
		}

		case 0x4 : {
			bitRate |= regVal;
			SerialPrint ( "Bit Rate (Chip Rate when Manchester encoding is enabled)\nBitRate : ");
			unsigned long val = 32UL * 1000UL * 1000UL / bitRate;
			Serial.println( val );
			SerialPrint( "\n" );
			break;
		}

		case 0x5 : {
			freqDev = ( (regVal & 0x3f) << 8 );
			break;
		}

		case 0x6 : {
			freqDev |= regVal;
			SerialPrint( "Frequency deviation\nFdev : " );
			unsigned long val = 61UL * freqDev;
			Serial.println( val );
			SerialPrint ( "\n" );
			break;
		}

		case 0x7 : {
			unsigned long tempVal = regVal;
			freqCenter = ( tempVal << 16 );
			break;
		}

		case 0x8 : {
			unsigned long tempVal = regVal;
			freqCenter = freqCenter | ( tempVal << 8 );
			break;
		}

		case 0x9 : {
			freqCenter = freqCenter | regVal;
			SerialPrint ( "RF Carrier frequency\nFRF : " );
			unsigned long val = 61UL * freqCenter;
			Serial.println( val );
			SerialPrint( "\n" );
			break;
		}

		case 0xa : {
			SerialPrint ( "RC calibration control & status\nRcCalDone : " );
			if ( 0x40 & regVal ) {
				SerialPrint ( "1 -> RC calibration is over\n" );
			} else {
				SerialPrint ( "0 -> RC calibration is in progress\n" );
			}

			SerialPrint ( "\n" );
			break;
		}

		case 0xb : {
			SerialPrint ( "Improved AFC routine for signals with modulation index lower than 2.  Refer to section 3.4.16 for details\nAfcLowBetaOn : " );
			if ( 0x20 & regVal ) {
				SerialPrint ( "1 -> Improved AFC routine\n" );
			} else {
				SerialPrint ( "0 -> Standard AFC routine\n" );
			}
			SerialPrint ( "\n" );
			break;
		}

		case 0xc : {
			SerialPrint ( "Reserved\n\n" );
			break;
		}

		case 0xd : {
			byte val;
			SerialPrint ( "Resolution of Listen mode Idle time (calibrated RC osc):\nListenResolIdle : " );
			val = regVal >> 6;
			if ( val == 0b00 ) {
				SerialPrint ( "00 -> reserved\n" );
			} else if ( val == 0b01 ) {
				SerialPrint ( "01 -> 64 us\n" );
			} else if ( val == 0b10 ) {
				SerialPrint ( "10 -> 4.1 ms\n" );
			} else if ( val == 0b11 ) {
				SerialPrint ( "11 -> 262 ms\n" );
			}

			SerialPrint ( "\nResolution of Listen mode Rx time (calibrated RC osc):\nListenResolRx : " );
			val = (regVal >> 4) & 0x3;
			if ( val == 0b00 ) {
				SerialPrint ( "00 -> reserved\n" );
			} else if ( val == 0b01 ) {
				SerialPrint ( "01 -> 64 us\n" );
			} else if ( val == 0b10 ) {
				SerialPrint ( "10 -> 4.1 ms\n" );
			} else if ( val == 0b11 ) {
				SerialPrint ( "11 -> 262 ms\n" );
			}

			SerialPrint ( "\nCriteria for packet acceptance in Listen mode:\nListenCriteria : " );
			if ( 0x8 & regVal ) {
				SerialPrint ( "1 -> signal strength is above RssiThreshold and SyncAddress matched\n" );
			} else {
				SerialPrint ( "0 -> signal strength is above RssiThreshold\n" );
			}

			SerialPrint ( "\nAction taken after acceptance of a packet in Listen mode:\nListenEnd : " );
			val = (regVal >> 1 ) & 0x3;
			if ( val == 0b00 ) {
				SerialPrint ( "00 -> chip stays in Rx mode. Listen mode stops and must be disabled (see section 4.3)\n" );
			} else if ( val == 0b01 ) {
				SerialPrint ( "01 -> chip stays in Rx mode until PayloadReady or Timeout interrupt occurs.  It then goes to the mode defined by Mode. Listen mode stops and must be disabled (see section 4.3)\n" );
			} else if ( val == 0b10 ) {
				SerialPrint ( "10 -> chip stays in Rx mode until PayloadReady or Timeout occurs.  Listen mode then resumes in Idle state.  FIFO content is lost at next Rx wakeup.\n" );
			} else if ( val == 0b11 ) {
				SerialPrint ( "11 -> Reserved\n" );
			}


			SerialPrint ( "\n" );
			break;
		}

		default : {
		}
		}
#endif
	}
	unselect();
}

uint8_t RFM69::readTemperature(uint8_t calFactor) // returns centigrade
{
	setMode(RFM69_MODE_STANDBY);
	writeReg(REG_TEMP1, RF_TEMP1_MEAS_START);
	while ((readReg(REG_TEMP1) & RF_TEMP1_MEAS_RUNNING)) {}
	return ~readReg(REG_TEMP2) + COURSE_TEMP_COEF +
	       calFactor; // 'complement' corrects the slope, rising temp = rising val
} // COURSE_TEMP_COEF puts reading in the ballpark, user can add additional correction

void RFM69::rcCalibration()
{
	writeReg(REG_OSC1, RF_OSC1_RCCAL_START);
	while ((readReg(REG_OSC1) & RF_OSC1_RCCAL_DONE) == 0x00) {}
}
