Diff: RH_RF95.cpp

Revision:

0:ab4e012489ef

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RH_RF95.cpp	Thu Oct 15 01:27:00 2015 +0000
@@ -0,0 +1,393 @@
+// RH_RF22.cpp
+//
+// Copyright (C) 2011 Mike McCauley
+// $Id: RH_RF95.cpp,v 1.8 2015/08/12 23:18:51 mikem Exp $
+
+#include <RH_RF95.h>
+
+// Interrupt vectors for the 3 Arduino interrupt pins
+// Each interrupt can be handled by a different instance of RH_RF95, allowing you to have
+// 2 or more LORAs per Arduino
+RH_RF95* RH_RF95::_deviceForInterrupt[RH_RF95_NUM_INTERRUPTS] = {0, 0, 0};
+uint8_t RH_RF95::_interruptCount = 0; // Index into _deviceForInterrupt for next device
+
+// These are indexed by the values of ModemConfigChoice
+// Stored in flash (program) memory to save SRAM
+PROGMEM static const RH_RF95::ModemConfig MODEM_CONFIG_TABLE[] =
+{
+    //  1d,     1e,      26
+    { 0x72,   0x74,    0x00}, // Bw125Cr45Sf128 (the chip default)
+    { 0x92,   0x74,    0x00}, // Bw500Cr45Sf128
+    { 0x48,   0x94,    0x00}, // Bw31_25Cr48Sf512
+    { 0x78,   0xc4,    0x00}, // Bw125Cr48Sf4096
+    
+};
+
+RH_RF95::RH_RF95(PINS slaveSelectPin, PINS interruptPin, RHGenericSPI& spi)
+    :
+    RHSPIDriver(slaveSelectPin, spi),
+    _rxBufValid(0),
+ 	_interruptPin(interruptPin)
+{
+    _myInterruptIndex = 0xff; // Not allocated yet
+}
+
+bool RH_RF95::init()
+{
+    if (!RHSPIDriver::init())
+	return false;
+
+#if (RH_PLATFORM != RH_PLATFORM_MBED)
+    // Determine the interrupt number that corresponds to the interruptPin
+    int interruptNumber = digitalPinToInterrupt(_interruptPin);
+    if (interruptNumber == NOT_AN_INTERRUPT)
+	return false;
+#endif
+
+    // No way to check the device type :-(
+    
+    // Set sleep mode, so we can also set LORA mode:
+    spiWrite(RH_RF95_REG_01_OP_MODE, RH_RF95_MODE_SLEEP | RH_RF95_LONG_RANGE_MODE);
+    delay(10); // Wait for sleep mode to take over from say, CAD
+    // Check we are in sleep mode, with LORA set
+    if (spiRead(RH_RF95_REG_01_OP_MODE) != (RH_RF95_MODE_SLEEP | RH_RF95_LONG_RANGE_MODE))
+    {
+//	Serial.println(spiRead(RH_RF95_REG_01_OP_MODE), HEX);
+	return false; // No device present?
+    }
+
+#if (RH_PLATFORM != RH_PLATFORM_MBED)
+    // Add by Adrien van den Bossche <vandenbo@univ-tlse2.fr> for Teensy
+    // ARM M4 requires the below. else pin interrupt doesn't work properly.
+    // On all other platforms, its innocuous, belt and braces
+    pinMode(_interruptPin, INPUT); 
+#endif
+
+    // Set up interrupt handler
+    // Since there are a limited number of interrupt glue functions isr*() available,
+    // we can only support a limited number of devices simultaneously
+    // ON some devices, notably most Arduinos, the interrupt pin passed in is actuallt the 
+    // interrupt number. You have to figure out the interruptnumber-to-interruptpin mapping
+    // yourself based on knwledge of what Arduino board you are running on.
+    if (_myInterruptIndex == 0xff)
+    {
+	// First run, no interrupt allocated yet
+	if (_interruptCount <= RH_RF95_NUM_INTERRUPTS)
+	    _myInterruptIndex = _interruptCount++;
+	else
+	    return false; // Too many devices, not enough interrupt vectors
+    }
+    _deviceForInterrupt[_myInterruptIndex] = this;
+    
+#if (RH_PLATFORM == RH_PLATFORM_MBED)
+    if (_myInterruptIndex == 0)
+		_interruptPin.rise(&isr0);
+    else if (_myInterruptIndex == 1)
+		_interruptPin.rise(&isr1);
+    else if (_myInterruptIndex == 2)
+		_interruptPin.rise(&isr2);
+    else
+	return false; // Too many devices, not enough interrupt vectors
+#else
+    if (_myInterruptIndex == 0)
+	attachInterrupt(interruptNumber, isr0, RISING);
+    else if (_myInterruptIndex == 1)
+	attachInterrupt(interruptNumber, isr1, RISING);
+    else if (_myInterruptIndex == 2)
+	attachInterrupt(interruptNumber, isr2, RISING);
+    else
+	return false; // Too many devices, not enough interrupt vectors
+#endif
+    // Set up FIFO
+    // We configure so that we can use the entire 256 byte FIFO for either receive
+    // or transmit, but not both at the same time
+    spiWrite(RH_RF95_REG_0E_FIFO_TX_BASE_ADDR, 0);
+    spiWrite(RH_RF95_REG_0F_FIFO_RX_BASE_ADDR, 0);
+
+    // Packet format is preamble + explicit-header + payload + crc
+    // Explicit Header Mode
+    // payload is TO + FROM + ID + FLAGS + message data
+    // RX mode is implmented with RXCONTINUOUS
+    // max message data length is 255 - 4 = 251 octets
+
+    setModeIdle();
+
+    // Set up default configuration
+    // No Sync Words in LORA mode.
+    setModemConfig(Bw125Cr45Sf128); // Radio default
+//    setModemConfig(Bw125Cr48Sf4096); // slow and reliable?
+    setPreambleLength(8); // Default is 8
+    // An innocuous ISM frequency, same as RF22's
+    setFrequency(434.0);
+    // Lowish power
+    setTxPower(13);
+
+    return true;
+}
+
+// C++ level interrupt handler for this instance
+// LORA is unusual in that it has several interrupt lines, and not a single, combined one.
+// On MiniWirelessLoRa, only one of the several interrupt lines (DI0) from the RFM95 is usefuly 
+// connnected to the processor.
+// We use this to get RxDone and TxDone interrupts
+void RH_RF95::handleInterrupt()
+{
+    // Read the interrupt register
+    uint8_t irq_flags = spiRead(RH_RF95_REG_12_IRQ_FLAGS);
+    if (_mode == RHModeRx && irq_flags & (RH_RF95_RX_TIMEOUT | RH_RF95_PAYLOAD_CRC_ERROR))
+    {
+	_rxBad++;
+    }
+    else if (_mode == RHModeRx && irq_flags & RH_RF95_RX_DONE)
+    {
+	// Have received a packet
+	uint8_t len = spiRead(RH_RF95_REG_13_RX_NB_BYTES);
+
+	// Reset the fifo read ptr to the beginning of the packet
+	spiWrite(RH_RF95_REG_0D_FIFO_ADDR_PTR, spiRead(RH_RF95_REG_10_FIFO_RX_CURRENT_ADDR));
+	spiBurstRead(RH_RF95_REG_00_FIFO, _buf, len);
+	_bufLen = len;
+	spiWrite(RH_RF95_REG_12_IRQ_FLAGS, 0xff); // Clear all IRQ flags
+
+	// Remember the RSSI of this packet
+	// this is according to the doc, but is it really correct?
+	// weakest receiveable signals are reported RSSI at about -66
+	_lastRssi = spiRead(RH_RF95_REG_1A_PKT_RSSI_VALUE) - 137;
+
+	// We have received a message.
+	validateRxBuf(); 
+	if (_rxBufValid)
+	    setModeIdle(); // Got one 
+    }
+    else if (_mode == RHModeTx && irq_flags & RH_RF95_TX_DONE)
+    {
+	_txGood++;
+	setModeIdle();
+    }
+    
+    spiWrite(RH_RF95_REG_12_IRQ_FLAGS, 0xff); // Clear all IRQ flags
+}
+
+// These are low level functions that call the interrupt handler for the correct
+// instance of RH_RF95.
+// 3 interrupts allows us to have 3 different devices
+void RH_RF95::isr0()
+{
+    if (_deviceForInterrupt[0])
+	_deviceForInterrupt[0]->handleInterrupt();
+}
+void RH_RF95::isr1()
+{
+    if (_deviceForInterrupt[1])
+	_deviceForInterrupt[1]->handleInterrupt();
+}
+void RH_RF95::isr2()
+{
+    if (_deviceForInterrupt[2])
+	_deviceForInterrupt[2]->handleInterrupt();
+}
+
+// Check whether the latest received message is complete and uncorrupted
+void RH_RF95::validateRxBuf()
+{
+    if (_bufLen < 4)
+	return; // Too short to be a real message
+    // Extract the 4 headers
+    _rxHeaderTo    = _buf[0];
+    _rxHeaderFrom  = _buf[1];
+    _rxHeaderId    = _buf[2];
+    _rxHeaderFlags = _buf[3];
+    if (_promiscuous ||
+	_rxHeaderTo == _thisAddress ||
+	_rxHeaderTo == RH_BROADCAST_ADDRESS)
+    {
+	_rxGood++;
+	_rxBufValid = true;
+    }
+}
+
+bool RH_RF95::available()
+{
+    if (_mode == RHModeTx)
+	return false;
+    setModeRx();
+    return _rxBufValid; // Will be set by the interrupt handler when a good message is received
+}
+
+void RH_RF95::clearRxBuf()
+{
+    ATOMIC_BLOCK_START;
+    _rxBufValid = false;
+    _bufLen = 0;
+    ATOMIC_BLOCK_END;
+}
+
+bool RH_RF95::recv(uint8_t* buf, uint8_t* len)
+{
+    if (!available())
+	return false;
+    if (buf && len)
+    {
+	ATOMIC_BLOCK_START;
+	// Skip the 4 headers that are at the beginning of the rxBuf
+	if (*len > _bufLen-RH_RF95_HEADER_LEN)
+	    *len = _bufLen-RH_RF95_HEADER_LEN;
+	memcpy(buf, _buf+RH_RF95_HEADER_LEN, *len);
+	ATOMIC_BLOCK_END;
+    }
+    clearRxBuf(); // This message accepted and cleared
+    return true;
+}
+
+bool RH_RF95::send(const uint8_t* data, uint8_t len)
+{
+    if (len > RH_RF95_MAX_MESSAGE_LEN)
+	return false;
+
+    waitPacketSent(); // Make sure we dont interrupt an outgoing message
+    setModeIdle();
+
+    // Position at the beginning of the FIFO
+    spiWrite(RH_RF95_REG_0D_FIFO_ADDR_PTR, 0);
+    // The headers
+    spiWrite(RH_RF95_REG_00_FIFO, _txHeaderTo);
+    spiWrite(RH_RF95_REG_00_FIFO, _txHeaderFrom);
+    spiWrite(RH_RF95_REG_00_FIFO, _txHeaderId);
+    spiWrite(RH_RF95_REG_00_FIFO, _txHeaderFlags);
+    // The message data
+    spiBurstWrite(RH_RF95_REG_00_FIFO, data, len);
+    spiWrite(RH_RF95_REG_22_PAYLOAD_LENGTH, len + RH_RF95_HEADER_LEN);
+
+    setModeTx(); // Start the transmitter
+    // when Tx is done, interruptHandler will fire and radio mode will return to STANDBY
+    return true;
+}
+
+bool RH_RF95::printRegisters()
+{
+#ifdef RH_HAVE_SERIAL
+    uint8_t registers[] = { 0x01, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x014, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27};
+
+    uint8_t i;
+    for (i = 0; i < sizeof(registers); i++)
+    {
+	Serial.print(registers[i], HEX);
+	Serial.print(": ");
+	Serial.println(spiRead(registers[i]), HEX);
+    }
+#endif
+    return true;
+}
+
+uint8_t RH_RF95::maxMessageLength()
+{
+    return RH_RF95_MAX_MESSAGE_LEN;
+}
+
+bool RH_RF95::setFrequency(float centre)
+{
+    // Frf = FRF / FSTEP
+    uint32_t frf = (centre * 1000000.0) / RH_RF95_FSTEP;
+    spiWrite(RH_RF95_REG_06_FRF_MSB, (frf >> 16) & 0xff);
+    spiWrite(RH_RF95_REG_07_FRF_MID, (frf >> 8) & 0xff);
+    spiWrite(RH_RF95_REG_08_FRF_LSB, frf & 0xff);
+
+    return true;
+}
+
+void RH_RF95::setModeIdle()
+{
+    if (_mode != RHModeIdle)
+    {
+	spiWrite(RH_RF95_REG_01_OP_MODE, RH_RF95_MODE_STDBY);
+	_mode = RHModeIdle;
+    }
+}
+
+bool RH_RF95::sleep()
+{
+    if (_mode != RHModeSleep)
+    {
+	spiWrite(RH_RF95_REG_01_OP_MODE, RH_RF95_MODE_SLEEP);
+	_mode = RHModeSleep;
+    }
+    return true;
+}
+
+void RH_RF95::setModeRx()
+{
+    if (_mode != RHModeRx)
+    {
+	spiWrite(RH_RF95_REG_01_OP_MODE, RH_RF95_MODE_RXCONTINUOUS);
+	spiWrite(RH_RF95_REG_40_DIO_MAPPING1, 0x00); // Interrupt on RxDone
+	_mode = RHModeRx;
+    }
+}
+
+void RH_RF95::setModeTx()
+{
+    if (_mode != RHModeTx)
+    {
+	spiWrite(RH_RF95_REG_01_OP_MODE, RH_RF95_MODE_TX);
+	spiWrite(RH_RF95_REG_40_DIO_MAPPING1, 0x40); // Interrupt on TxDone
+	_mode = RHModeTx;
+    }
+}
+
+void RH_RF95::setTxPower(int8_t power)
+{
+    if (power > 23)
+	power = 23;
+    if (power < 5)
+	power = 5;
+
+    // For RH_RF95_PA_DAC_ENABLE, manual says '+20dBm on PA_BOOST when OutputPower=0xf'
+    // RH_RF95_PA_DAC_ENABLE actually adds about 3dBm to all power levels. We will us it
+    // for 21, 22 and 23dBm
+    if (power > 20)
+    {
+	spiWrite(RH_RF95_REG_4D_PA_DAC, RH_RF95_PA_DAC_ENABLE);
+	power -= 3;
+    }
+    else
+    {
+	spiWrite(RH_RF95_REG_4D_PA_DAC, RH_RF95_PA_DAC_DISABLE);
+    }
+
+    // RFM95/96/97/98 does not have RFO pins connected to anything. Only PA_BOOST
+    // pin is connected, so must use PA_BOOST
+    // Pout = 2 + OutputPower.
+    // The documentation is pretty confusing on this topic: PaSelect says the max power is 20dBm,
+    // but OutputPower claims it would be 17dBm.
+    // My measurements show 20dBm is correct
+    spiWrite(RH_RF95_REG_09_PA_CONFIG, RH_RF95_PA_SELECT | (power-5));
+}
+
+// Sets registers from a canned modem configuration structure
+void RH_RF95::setModemRegisters(const ModemConfig* config)
+{
+    spiWrite(RH_RF95_REG_1D_MODEM_CONFIG1,       config->reg_1d);
+    spiWrite(RH_RF95_REG_1E_MODEM_CONFIG2,       config->reg_1e);
+    spiWrite(RH_RF95_REG_26_MODEM_CONFIG3,       config->reg_26);
+}
+
+// Set one of the canned FSK Modem configs
+// Returns true if its a valid choice
+bool RH_RF95::setModemConfig(ModemConfigChoice index)
+{
+    if (index > (signed int)(sizeof(MODEM_CONFIG_TABLE) / sizeof(ModemConfig)))
+        return false;
+
+    ModemConfig cfg;
+    memcpy_P(&cfg, &MODEM_CONFIG_TABLE[index], sizeof(RH_RF95::ModemConfig));
+    setModemRegisters(&cfg);
+
+    return true;
+}
+
+void RH_RF95::setPreambleLength(uint16_t bytes)
+{
+    spiWrite(RH_RF95_REG_20_PREAMBLE_MSB, bytes >> 8);
+    spiWrite(RH_RF95_REG_21_PREAMBLE_LSB, bytes & 0xff);
+}
+