Fix ADR channel mask handling

Dependents:  

Fork of lmic_MOTE_L152RC by canuck lehead

Revision:
0:f2716e543d97
Child:
2:edb5d1f3deeb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/radio.cpp	Tue Jun 02 19:04:29 2015 +0000
@@ -0,0 +1,824 @@
+/*******************************************************************************
+ * Copyright (c) 2014-2015 IBM Corporation.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    IBM Zurich Research Lab - initial API, implementation and documentation
+ *******************************************************************************/
+
+#include "lmic.h"
+
+// ---------------------------------------- 
+// Registers Mapping
+#define RegFifo                                    0x00 // common
+#define RegOpMode                                  0x01 // common
+#define FSKRegBitrateMsb                           0x02
+#define FSKRegBitrateLsb                           0x03
+#define FSKRegFdevMsb                              0x04
+#define FSKRegFdevLsb                              0x05
+#define RegFrfMsb                                  0x06 // common
+#define RegFrfMid                                  0x07 // common
+#define RegFrfLsb                                  0x08 // common
+#define RegPaConfig                                0x09 // common
+#define RegPaRamp                                  0x0A // common
+#define RegOcp                                     0x0B // common
+#define RegLna                                     0x0C // common
+#define FSKRegRxConfig                             0x0D
+#define LORARegFifoAddrPtr                         0x0D
+#define FSKRegRssiConfig                           0x0E
+#define LORARegFifoTxBaseAddr                      0x0E
+#define FSKRegRssiCollision                        0x0F
+#define LORARegFifoRxBaseAddr                      0x0F 
+#define FSKRegRssiThresh                           0x10
+#define LORARegFifoRxCurrentAddr                   0x10
+#define FSKRegRssiValue                            0x11
+#define LORARegIrqFlagsMask                        0x11 
+#define FSKRegRxBw                                 0x12
+#define LORARegIrqFlags                            0x12 
+#define FSKRegAfcBw                                0x13
+#define LORARegRxNbBytes                           0x13 
+#define FSKRegOokPeak                              0x14
+#define LORARegRxHeaderCntValueMsb                 0x14 
+#define FSKRegOokFix                               0x15
+#define LORARegRxHeaderCntValueLsb                 0x15 
+#define FSKRegOokAvg                               0x16
+#define LORARegRxPacketCntValueMsb                 0x16 
+#define LORARegRxpacketCntValueLsb                 0x17 
+#define LORARegModemStat                           0x18 
+#define LORARegPktSnrValue                         0x19 
+#define FSKRegAfcFei                               0x1A
+#define LORARegPktRssiValue                        0x1A 
+#define FSKRegAfcMsb                               0x1B
+#define LORARegRssiValue                           0x1B 
+#define FSKRegAfcLsb                               0x1C
+#define LORARegHopChannel                          0x1C 
+#define FSKRegFeiMsb                               0x1D
+#define LORARegModemConfig1                        0x1D 
+#define FSKRegFeiLsb                               0x1E
+#define LORARegModemConfig2                        0x1E 
+#define FSKRegPreambleDetect                       0x1F
+#define LORARegSymbTimeoutLsb                      0x1F 
+#define FSKRegRxTimeout1                           0x20
+#define LORARegPreambleMsb                         0x20 
+#define FSKRegRxTimeout2                           0x21
+#define LORARegPreambleLsb                         0x21 
+#define FSKRegRxTimeout3                           0x22
+#define LORARegPayloadLength                       0x22 
+#define FSKRegRxDelay                              0x23
+#define LORARegPayloadMaxLength                    0x23 
+#define FSKRegOsc                                  0x24
+#define LORARegHopPeriod                           0x24 
+#define FSKRegPreambleMsb                          0x25
+#define LORARegFifoRxByteAddr                      0x25
+#define LORARegModemConfig3                        0x26
+#define FSKRegPreambleLsb                          0x26
+#define FSKRegSyncConfig                           0x27
+#define LORARegFeiMsb                              0x28
+#define FSKRegSyncValue1                           0x28
+#define LORAFeiMib                                 0x29
+#define FSKRegSyncValue2                           0x29
+#define LORARegFeiLsb                              0x2A
+#define FSKRegSyncValue3                           0x2A
+#define FSKRegSyncValue4                           0x2B
+#define LORARegRssiWideband                        0x2C
+#define FSKRegSyncValue5                           0x2C
+#define FSKRegSyncValue6                           0x2D
+#define FSKRegSyncValue7                           0x2E
+#define FSKRegSyncValue8                           0x2F
+#define FSKRegPacketConfig1                        0x30
+#define FSKRegPacketConfig2                        0x31
+#define LORARegDetectOptimize                      0x31
+#define FSKRegPayloadLength                        0x32
+#define FSKRegNodeAdrs                             0x33
+#define LORARegInvertIQ                            0x33
+#define FSKRegBroadcastAdrs                        0x34
+#define FSKRegFifoThresh                           0x35
+#define FSKRegSeqConfig1                           0x36
+#define FSKRegSeqConfig2                           0x37
+#define LORARegDetectionThreshold                  0x37
+#define FSKRegTimerResol                           0x38
+#define FSKRegTimer1Coef                           0x39
+#define LORARegSyncWord                            0x39
+#define FSKRegTimer2Coef                           0x3A
+#define FSKRegImageCal                             0x3B
+#define LORARegTimingInvert                        0x3B
+#define FSKRegTemp                                 0x3C
+#define FSKRegLowBat                               0x3D
+#define FSKRegIrqFlags1                            0x3E
+#define FSKRegIrqFlags2                            0x3F
+#define RegDioMapping1                             0x40 // common
+#define RegDioMapping2                             0x41 // common
+#define RegVersion                                 0x42 // common
+// #define RegAgcRef                                  0x43 // common
+// #define RegAgcThresh1                              0x44 // common
+// #define RegAgcThresh2                              0x45 // common
+// #define RegAgcThresh3                              0x46 // common
+// #define RegPllHop                                  0x4B // common
+// #define RegTcxo                                    0x58 // common
+#define RegPaDac                                   0x5A // common
+// #define RegPll                                     0x5C // common
+// #define RegPllLowPn                                0x5E // common
+// #define RegFormerTemp                              0x6C // common
+// #define RegBitRateFrac                             0x70 // common
+
+// ----------------------------------------
+// spread factors and mode for RegModemConfig2
+#define SX1272_MC2_FSK  0x00
+#define SX1272_MC2_SF7  0x70
+#define SX1272_MC2_SF8  0x80
+#define SX1272_MC2_SF9  0x90
+#define SX1272_MC2_SF10 0xA0
+#define SX1272_MC2_SF11 0xB0
+#define SX1272_MC2_SF12 0xC0
+// bandwidth for RegModemConfig1
+#define SX1272_MC1_BW_125  0x00
+#define SX1272_MC1_BW_250  0x40
+#define SX1272_MC1_BW_500  0x80
+// coding rate for RegModemConfig1
+#define SX1272_MC1_CR_4_5 0x08
+#define SX1272_MC1_CR_4_6 0x10
+#define SX1272_MC1_CR_4_7 0x18
+#define SX1272_MC1_CR_4_8 0x20
+#define SX1272_MC1_IMPLICIT_HEADER_MODE_ON 0x04 // required for receive
+#define SX1272_MC1_RX_PAYLOAD_CRCON        0x02
+#define SX1272_MC1_LOW_DATA_RATE_OPTIMIZE  0x01 // mandated for SF11 and SF12
+// transmit power configuration for RegPaConfig
+#define SX1272_PAC_PA_SELECT_PA_BOOST 0x80
+#define SX1272_PAC_PA_SELECT_RFIO_PIN 0x00
+
+
+// sx1276 RegModemConfig1
+#define SX1276_MC1_BW_125                0x70
+#define SX1276_MC1_BW_250                0x80
+#define SX1276_MC1_BW_500                0x90
+#define SX1276_MC1_CR_4_5            0x02
+#define SX1276_MC1_CR_4_6            0x04
+#define SX1276_MC1_CR_4_7            0x06
+#define SX1276_MC1_CR_4_8            0x08
+
+#define SX1276_MC1_IMPLICIT_HEADER_MODE_ON    0x01 
+                                                    
+// sx1276 RegModemConfig2          
+#define SX1276_MC2_RX_PAYLOAD_CRCON        0x04
+
+// sx1276 RegModemConfig3          
+#define SX1276_MC3_LOW_DATA_RATE_OPTIMIZE  0x08
+#define SX1276_MC3_AGCAUTO                 0x04
+
+// preamble for lora networks (nibbles swapped)
+#define LORA_MAC_PREAMBLE                  0x34
+
+#define RXLORA_RXMODE_RSSI_REG_MODEM_CONFIG1 0x0A
+#ifdef CFG_sx1276_radio
+#define RXLORA_RXMODE_RSSI_REG_MODEM_CONFIG2 0x70
+#elif defined(CFG_sx1272_radio)
+#define RXLORA_RXMODE_RSSI_REG_MODEM_CONFIG2 0x74
+#endif
+
+
+
+// ---------------------------------------- 
+// Constants for radio registers
+#define OPMODE_LORA      0x80
+#define OPMODE_MASK      0x07
+#define OPMODE_SLEEP     0x00
+#define OPMODE_STANDBY   0x01
+#define OPMODE_FSTX      0x02
+#define OPMODE_TX        0x03
+#define OPMODE_FSRX      0x04
+#define OPMODE_RX        0x05
+#define OPMODE_RX_SINGLE 0x06 
+#define OPMODE_CAD       0x07 
+
+// ----------------------------------------
+// Bits masking the corresponding IRQs from the radio
+#define IRQ_LORA_RXTOUT_MASK 0x80
+#define IRQ_LORA_RXDONE_MASK 0x40
+#define IRQ_LORA_CRCERR_MASK 0x20
+#define IRQ_LORA_HEADER_MASK 0x10
+#define IRQ_LORA_TXDONE_MASK 0x08
+#define IRQ_LORA_CDDONE_MASK 0x04
+#define IRQ_LORA_FHSSCH_MASK 0x02
+#define IRQ_LORA_CDDETD_MASK 0x01
+
+#define IRQ_FSK1_MODEREADY_MASK         0x80
+#define IRQ_FSK1_RXREADY_MASK           0x40
+#define IRQ_FSK1_TXREADY_MASK           0x20
+#define IRQ_FSK1_PLLLOCK_MASK           0x10
+#define IRQ_FSK1_RSSI_MASK              0x08
+#define IRQ_FSK1_TIMEOUT_MASK           0x04
+#define IRQ_FSK1_PREAMBLEDETECT_MASK    0x02
+#define IRQ_FSK1_SYNCADDRESSMATCH_MASK  0x01
+#define IRQ_FSK2_FIFOFULL_MASK          0x80
+#define IRQ_FSK2_FIFOEMPTY_MASK         0x40
+#define IRQ_FSK2_FIFOLEVEL_MASK         0x20
+#define IRQ_FSK2_FIFOOVERRUN_MASK       0x10
+#define IRQ_FSK2_PACKETSENT_MASK        0x08
+#define IRQ_FSK2_PAYLOADREADY_MASK      0x04
+#define IRQ_FSK2_CRCOK_MASK             0x02
+#define IRQ_FSK2_LOWBAT_MASK            0x01
+
+// ----------------------------------------
+// DIO function mappings                D0D1D2D3
+#define MAP_DIO0_LORA_RXDONE   0x00  // 00------
+#define MAP_DIO0_LORA_TXDONE   0x40  // 01------
+#define MAP_DIO1_LORA_RXTOUT   0x00  // --00----
+#define MAP_DIO1_LORA_NOP      0x30  // --11----
+#define MAP_DIO2_LORA_NOP      0xC0  // ----11--
+
+#define MAP_DIO0_FSK_READY     0x00  // 00------ (packet sent / payload ready)
+#define MAP_DIO1_FSK_NOP       0x30  // --11----
+#define MAP_DIO2_FSK_TXNOP     0x04  // ----01--
+#define MAP_DIO2_FSK_TIMEOUT   0x08  // ----10--
+
+
+// FSK IMAGECAL defines
+#define RF_IMAGECAL_AUTOIMAGECAL_MASK               0x7F
+#define RF_IMAGECAL_AUTOIMAGECAL_ON                 0x80
+#define RF_IMAGECAL_AUTOIMAGECAL_OFF                0x00  // Default
+
+#define RF_IMAGECAL_IMAGECAL_MASK                   0xBF
+#define RF_IMAGECAL_IMAGECAL_START                  0x40
+
+#define RF_IMAGECAL_IMAGECAL_RUNNING                0x20
+#define RF_IMAGECAL_IMAGECAL_DONE                   0x00  // Default
+
+
+// RADIO STATE
+// (initialized by radio_init(), used by radio_rand1())
+static u1_t randbuf[16];
+static u1_t PaSelect;
+
+#ifdef CFG_sx1276_radio
+#define LNA_RX_GAIN (0x20|0x1)
+#elif defined(CFG_sx1272_radio)
+#define LNA_RX_GAIN (0x20|0x03)
+#else
+#error Missing CFG_sx1272_radio/CFG_sx1276_radio
+#endif
+
+
+static void writeReg (u1_t addr, u1_t data ) {
+    hal_pin_nss(0);
+    hal_spi(addr | 0x80);
+    hal_spi(data);
+    hal_pin_nss(1);
+}
+
+static u1_t readReg (u1_t addr) {
+    hal_pin_nss(0);
+    hal_spi(addr & 0x7F);
+    u1_t val = hal_spi(0x00);
+    hal_pin_nss(1);
+    return val;
+}
+
+static void writeBuf (u1_t addr, xref2u1_t buf, u1_t len) {
+    hal_pin_nss(0);
+    hal_spi(addr | 0x80);
+    for (u1_t i=0; i<len; i++) {
+        hal_spi(buf[i]);
+    }
+    hal_pin_nss(1);
+}
+
+static void readBuf (u1_t addr, xref2u1_t buf, u1_t len) {
+    hal_pin_nss(0);
+    hal_spi(addr & 0x7F);
+    for (u1_t i=0; i<len; i++) {
+        buf[i] = hal_spi(0x00);
+    }
+    hal_pin_nss(1);
+}
+
+static void opmode (u1_t mode) {
+    hal_opmode(mode, PaSelect);
+    writeReg(RegOpMode, (readReg(RegOpMode) & ~OPMODE_MASK) | mode);
+}
+
+static void opmodeLora() {
+    u1_t u = OPMODE_LORA;
+#ifdef CFG_sx1276_radio
+    u |= 0x8;   // TBD: sx1276 high freq
+#endif
+    writeReg(RegOpMode, u);
+}
+
+static void opmodeFSK() {
+    u1_t u = 0;
+#ifdef CFG_sx1276_radio
+    u |= 0x8;   // TBD: sx1276 high freq
+#endif
+    writeReg(RegOpMode, u);
+}
+
+// configure LoRa modem (cfg1, cfg2)
+static void configLoraModem () {
+    sf_t sf = getSf(LMIC.rps);
+
+#ifdef CFG_sx1276_radio
+        u1_t mc1 = 0, mc2 = 0, mc3 = 0;
+
+        switch (getBw(LMIC.rps)) {
+        case BW125: mc1 |= SX1276_MC1_BW_125; break;
+        case BW250: mc1 |= SX1276_MC1_BW_250; break;
+        case BW500: mc1 |= SX1276_MC1_BW_500; break;
+        default:
+            ASSERT(0);
+        }
+        switch( getCr(LMIC.rps) ) {
+        case CR_4_5: mc1 |= SX1276_MC1_CR_4_5; break;
+        case CR_4_6: mc1 |= SX1276_MC1_CR_4_6; break;
+        case CR_4_7: mc1 |= SX1276_MC1_CR_4_7; break;
+        case CR_4_8: mc1 |= SX1276_MC1_CR_4_8; break;
+        default:
+            ASSERT(0);
+        }
+
+        if (getIh(LMIC.rps)) {
+            mc1 |= SX1276_MC1_IMPLICIT_HEADER_MODE_ON;
+            writeReg(LORARegPayloadLength, getIh(LMIC.rps)); // required length
+        }
+        // set ModemConfig1
+        writeReg(LORARegModemConfig1, mc1);
+
+        mc2 = (SX1272_MC2_SF7 + ((sf-1)<<4));
+        if (getNocrc(LMIC.rps) == 0) {
+            mc2 |= SX1276_MC2_RX_PAYLOAD_CRCON;
+        }
+        writeReg(LORARegModemConfig2, mc2);
+        
+        mc3 = SX1276_MC3_AGCAUTO;
+        if ((sf == SF11 || sf == SF12) && getBw(LMIC.rps) == BW125) {
+            mc3 |= SX1276_MC3_LOW_DATA_RATE_OPTIMIZE;
+        }
+        writeReg(LORARegModemConfig3, mc3);
+#elif defined(CFG_sx1272_radio)
+        u1_t mc1 = (getBw(LMIC.rps)<<6);
+
+        switch( getCr(LMIC.rps) ) {
+        case CR_4_5: mc1 |= SX1272_MC1_CR_4_5; break;
+        case CR_4_6: mc1 |= SX1272_MC1_CR_4_6; break;
+        case CR_4_7: mc1 |= SX1272_MC1_CR_4_7; break;
+        case CR_4_8: mc1 |= SX1272_MC1_CR_4_8; break;
+        }
+        
+        if ((sf == SF11 || sf == SF12) && getBw(LMIC.rps) == BW125) {
+            mc1 |= SX1272_MC1_LOW_DATA_RATE_OPTIMIZE;
+        }
+        
+        if (getNocrc(LMIC.rps) == 0) {
+            mc1 |= SX1272_MC1_RX_PAYLOAD_CRCON;
+        }
+        
+        if (getIh(LMIC.rps)) {
+            mc1 |= SX1272_MC1_IMPLICIT_HEADER_MODE_ON;
+            writeReg(LORARegPayloadLength, getIh(LMIC.rps)); // required length
+        }
+        // set ModemConfig1
+        writeReg(LORARegModemConfig1, mc1);
+        
+        // set ModemConfig2 (sf, AgcAutoOn=1 SymbTimeoutHi=00)
+        writeReg(LORARegModemConfig2, (SX1272_MC2_SF7 + ((sf-1)<<4)) | 0x04);
+#else
+#error Missing CFG_sx1272_radio/CFG_sx1276_radio
+#endif /* CFG_sx1272_radio */
+}
+
+static void configChannel () {
+    // set frequency: FQ = (FRF * 32 Mhz) / (2 ^ 19)
+    u8_t frf = ((u8_t)LMIC.freq << 19) / 32000000;
+    writeReg(RegFrfMsb, (u1_t)(frf>>16));
+    writeReg(RegFrfMid, (u1_t)(frf>> 8));
+    writeReg(RegFrfLsb, (u1_t)(frf>> 0));
+}
+
+
+
+static void configPower () {
+#ifdef CFG_sx1276_radio
+    // no boost used for now
+    s1_t pw = (s1_t)LMIC.txpow;
+    if(pw >= 17) {
+        pw = 15;
+    } else if(pw < 2) {
+        pw = 2;
+    }
+    // check board type for BOOST pin
+    writeReg(RegPaConfig, (u1_t)(0x80|(pw&0xf)));
+    writeReg(RegPaDac, readReg(RegPaDac)|0x4);
+
+#elif defined(CFG_sx1272_radio)
+    // set PA config (2-17 dBm using PA_BOOST)
+    s1_t pw = (s1_t)LMIC.txpow;
+    if(pw > 17) {
+        pw = 17;
+    } else if(pw < 2) {
+        pw = 2;
+    }
+    
+    PaSelect = 0x80;    // use PA_BOOST 
+    //PaSelect = 0x00;    // use RFO for external amplifier
+    writeReg(RegPaConfig, (u1_t)(PaSelect|(pw-2)));
+#else
+#error Missing CFG_sx1272_radio/CFG_sx1276_radio
+#endif /* CFG_sx1272_radio */
+}
+
+static void txfsk () {
+    // select FSK modem (from sleep mode)
+    writeReg(RegOpMode, 0x10); // FSK, BT=0.5
+    ASSERT(readReg(RegOpMode) == 0x10);
+    // enter standby mode (required for FIFO loading))
+    opmode(OPMODE_STANDBY);
+    // set bitrate
+    writeReg(FSKRegBitrateMsb, 0x02); // 50kbps
+    writeReg(FSKRegBitrateLsb, 0x80);
+    // set frequency deviation
+    writeReg(FSKRegFdevMsb, 0x01); // +/- 25kHz
+    writeReg(FSKRegFdevLsb, 0x99);
+    // frame and packet handler settings
+    writeReg(FSKRegPreambleMsb, 0x00);
+    writeReg(FSKRegPreambleLsb, 0x05);
+    writeReg(FSKRegSyncConfig, 0x12);
+    writeReg(FSKRegPacketConfig1, 0xD0);
+    writeReg(FSKRegPacketConfig2, 0x40);
+    writeReg(FSKRegSyncValue1, 0xC1);
+    writeReg(FSKRegSyncValue2, 0x94);
+    writeReg(FSKRegSyncValue3, 0xC1);
+    // configure frequency
+    configChannel();
+    // configure output power
+    configPower();
+
+    // set the IRQ mapping DIO0=PacketSent DIO1=NOP DIO2=NOP
+    writeReg(RegDioMapping1, MAP_DIO0_FSK_READY|MAP_DIO1_FSK_NOP|MAP_DIO2_FSK_TXNOP);
+
+    // initialize the payload size and address pointers    
+    writeReg(FSKRegPayloadLength, LMIC.dataLen+1); // (insert length byte into payload))
+
+    // download length byte and buffer to the radio FIFO
+    writeReg(RegFifo, LMIC.dataLen);
+    writeBuf(RegFifo, LMIC.frame, LMIC.dataLen);
+
+    // enable antenna switch for TX
+    //hal_pin_rxtx(1);
+    
+    // now we actually start the transmission
+    opmode(OPMODE_TX);
+}
+
+static void txlora () {
+    // select LoRa modem (from sleep mode)
+    //writeReg(RegOpMode, OPMODE_LORA);
+    opmodeLora();
+    ASSERT((readReg(RegOpMode) & OPMODE_LORA) != 0);
+
+    // enter standby mode (required for FIFO loading))
+    opmode(OPMODE_STANDBY);
+    // configure LoRa modem (cfg1, cfg2)
+    configLoraModem();
+    // configure frequency
+    configChannel();
+    // configure output power
+    writeReg(RegPaRamp, (readReg(RegPaRamp) & 0xF0) | 0x08); // set PA ramp-up time 50 uSec
+    configPower();
+    // set sync word
+    writeReg(LORARegSyncWord, LORA_MAC_PREAMBLE);
+    
+    // set the IRQ mapping DIO0=TxDone DIO1=NOP DIO2=NOP
+    writeReg(RegDioMapping1, MAP_DIO0_LORA_TXDONE|MAP_DIO1_LORA_NOP|MAP_DIO2_LORA_NOP);
+    // clear all radio IRQ flags
+    writeReg(LORARegIrqFlags, 0xFF);
+    // mask all IRQs but TxDone
+    writeReg(LORARegIrqFlagsMask, ~IRQ_LORA_TXDONE_MASK);
+
+    // initialize the payload size and address pointers    
+    writeReg(LORARegFifoTxBaseAddr, 0x00);
+    writeReg(LORARegFifoAddrPtr, 0x00);
+    writeReg(LORARegPayloadLength, LMIC.dataLen);
+       
+    // download buffer to the radio FIFO
+    writeBuf(RegFifo, LMIC.frame, LMIC.dataLen);
+
+    // enable antenna switch for TX
+    //hal_pin_rxtx(1);
+    
+    // now we actually start the transmission
+    opmode(OPMODE_TX);
+}
+
+// start transmitter (buf=LMIC.frame, len=LMIC.dataLen)
+static void starttx () {
+    ASSERT( (readReg(RegOpMode) & OPMODE_MASK) == OPMODE_SLEEP );
+    if(getSf(LMIC.rps) == FSK) { // FSK modem
+        txfsk();
+    } else { // LoRa modem
+        txlora();
+    }
+    // the radio will go back to STANDBY mode as soon as the TX is finished
+    // the corresponding IRQ will inform us about completion.
+}
+
+enum { RXMODE_SINGLE, RXMODE_SCAN, RXMODE_RSSI };
+
+static const u1_t rxlorairqmask[] = {
+    [RXMODE_SINGLE] = IRQ_LORA_RXDONE_MASK|IRQ_LORA_RXTOUT_MASK,
+    [RXMODE_SCAN]   = IRQ_LORA_RXDONE_MASK,
+    [RXMODE_RSSI]   = 0x00,
+};
+
+// start LoRa receiver (time=LMIC.rxtime, timeout=LMIC.rxsyms, result=LMIC.frame[LMIC.dataLen])
+static void rxlora (u1_t rxmode) {
+    // select LoRa modem (from sleep mode)
+    opmodeLora();
+    ASSERT((readReg(RegOpMode) & OPMODE_LORA) != 0);
+    // enter standby mode (warm up))
+    opmode(OPMODE_STANDBY);
+    // don't use MAC settings at startup
+    if(rxmode == RXMODE_RSSI) { // use fixed settings for rssi scan
+        writeReg(LORARegModemConfig1, RXLORA_RXMODE_RSSI_REG_MODEM_CONFIG1);
+        writeReg(LORARegModemConfig2, RXLORA_RXMODE_RSSI_REG_MODEM_CONFIG2);
+    } else { // single or continuous rx mode
+        // configure LoRa modem (cfg1, cfg2)
+        configLoraModem();
+        // configure frequency
+        configChannel();
+    }
+    // set LNA gain
+    writeReg(RegLna, LNA_RX_GAIN); 
+    // set max payload size
+    writeReg(LORARegPayloadMaxLength, 64);
+    // use inverted I/Q signal (prevent mote-to-mote communication)
+    writeReg(LORARegInvertIQ, readReg(LORARegInvertIQ)|(1<<6));
+    // set symbol timeout (for single rx)
+    writeReg(LORARegSymbTimeoutLsb, LMIC.rxsyms);
+    // set sync word
+    writeReg(LORARegSyncWord, LORA_MAC_PREAMBLE);
+    
+    // configure DIO mapping DIO0=RxDone DIO1=RxTout DIO2=NOP
+    writeReg(RegDioMapping1, MAP_DIO0_LORA_RXDONE|MAP_DIO1_LORA_RXTOUT|MAP_DIO2_LORA_NOP);
+    // clear all radio IRQ flags
+    writeReg(LORARegIrqFlags, 0xFF);
+    // enable required radio IRQs
+    writeReg(LORARegIrqFlagsMask, ~rxlorairqmask[rxmode]);
+
+    // enable antenna switch for RX
+    //hal_pin_rxtx(0);
+
+    // now instruct the radio to receive
+    if (rxmode == RXMODE_SINGLE) { // single rx
+        hal_waitUntil(LMIC.rxtime); // busy wait until exact rx time
+        opmode(OPMODE_RX_SINGLE);
+    } else { // continous rx (scan or rssi)
+        opmode(OPMODE_RX); 
+    }
+}
+
+static void rxfsk (u1_t rxmode) {
+    // only single rx (no continuous scanning, no noise sampling)
+    ASSERT( rxmode == RXMODE_SINGLE );
+    // select FSK modem (from sleep mode)
+    //writeReg(RegOpMode, 0x00); // (not LoRa)
+    opmodeFSK();
+    ASSERT((readReg(RegOpMode) & OPMODE_LORA) == 0);
+    // enter standby mode (warm up))
+    opmode(OPMODE_STANDBY);
+    // configure frequency
+    configChannel();
+    // set LNA gain
+    //writeReg(RegLna, 0x20|0x03); // max gain, boost enable
+    writeReg(RegLna, LNA_RX_GAIN);
+    // configure receiver
+    writeReg(FSKRegRxConfig, 0x1E); // AFC auto, AGC, trigger on preamble?!?
+    // set receiver bandwidth
+    writeReg(FSKRegRxBw, 0x0B); // 50kHz SSb
+    // set AFC bandwidth
+    writeReg(FSKRegAfcBw, 0x12); // 83.3kHz SSB
+    // set preamble detection
+    writeReg(FSKRegPreambleDetect, 0xAA); // enable, 2 bytes, 10 chip errors
+    // set sync config
+    writeReg(FSKRegSyncConfig, 0x12); // no auto restart, preamble 0xAA, enable, fill FIFO, 3 bytes sync
+    // set packet config
+    writeReg(FSKRegPacketConfig1, 0xD8); // var-length, whitening, crc, no auto-clear, no adr filter
+    writeReg(FSKRegPacketConfig2, 0x40); // packet mode
+    // set sync value
+    writeReg(FSKRegSyncValue1, 0xC1);
+    writeReg(FSKRegSyncValue2, 0x94);
+    writeReg(FSKRegSyncValue3, 0xC1);
+    // set preamble timeout
+    writeReg(FSKRegRxTimeout2, 0xFF);//(LMIC.rxsyms+1)/2);
+    // set bitrate
+    writeReg(FSKRegBitrateMsb, 0x02); // 50kbps
+    writeReg(FSKRegBitrateLsb, 0x80);
+    // set frequency deviation
+    writeReg(FSKRegFdevMsb, 0x01); // +/- 25kHz
+    writeReg(FSKRegFdevLsb, 0x99);
+    
+    // configure DIO mapping DIO0=PayloadReady DIO1=NOP DIO2=TimeOut
+    writeReg(RegDioMapping1, MAP_DIO0_FSK_READY|MAP_DIO1_FSK_NOP|MAP_DIO2_FSK_TIMEOUT);
+
+    // enable antenna switch for RX
+    //hal_pin_rxtx(0);
+    
+    // now instruct the radio to receive
+    hal_waitUntil(LMIC.rxtime); // busy wait until exact rx time
+    opmode(OPMODE_RX); // no single rx mode available in FSK
+}
+
+static void startrx (u1_t rxmode) {
+    ASSERT( (readReg(RegOpMode) & OPMODE_MASK) == OPMODE_SLEEP );
+    if(getSf(LMIC.rps) == FSK) { // FSK modem
+        rxfsk(rxmode);
+    } else { // LoRa modem
+        rxlora(rxmode);
+    }
+    // the radio will go back to STANDBY mode as soon as the RX is finished
+    // or timed out, and the corresponding IRQ will inform us about completion.
+}
+
+// get random seed from wideband noise rssi
+void radio_init () {
+    hal_disableIRQs();
+
+    // manually reset radio
+#ifdef CFG_sx1276_radio
+    hal_pin_rst(0); // drive RST pin low
+#else
+    hal_pin_rst(1); // drive RST pin high
+#endif
+    hal_waitUntil(os_getTime()+ms2osticks(1)); // wait >100us
+    hal_pin_rst(2); // configure RST pin floating!
+    hal_waitUntil(os_getTime()+ms2osticks(5)); // wait 5ms
+
+    opmode(OPMODE_SLEEP);
+
+    // some sanity checks, e.g., read version number
+    u1_t v = readReg(RegVersion);
+#ifdef CFG_sx1276_radio
+    ASSERT(v == 0x12 ); 
+#elif defined(CFG_sx1272_radio)
+    ASSERT(v == 0x22);
+#else
+#error Missing CFG_sx1272_radio/CFG_sx1276_radio
+#endif
+    // seed 15-byte randomness via noise rssi
+    rxlora(RXMODE_RSSI);
+    while( (readReg(RegOpMode) & OPMODE_MASK) != OPMODE_RX ); // continuous rx
+    for(int i=1; i<16; i++) {
+        for(int j=0; j<8; j++) {
+            u1_t b; // wait for two non-identical subsequent least-significant bits
+            while( (b = readReg(LORARegRssiWideband) & 0x01) == (readReg(LORARegRssiWideband) & 0x01) );
+            randbuf[i] = (randbuf[i] << 1) | b;
+        }
+    }
+    randbuf[0] = 16; // set initial index
+  
+#ifdef CFG_sx1276mb1_board
+    // chain calibration
+    writeReg(RegPaConfig, 0);
+    
+    // Launch Rx chain calibration for LF band
+    writeReg(FSKRegImageCal, (readReg(FSKRegImageCal) & RF_IMAGECAL_IMAGECAL_MASK)|RF_IMAGECAL_IMAGECAL_START);
+    while((readReg(FSKRegImageCal)&RF_IMAGECAL_IMAGECAL_RUNNING) == RF_IMAGECAL_IMAGECAL_RUNNING){ ; }
+
+    // Sets a Frequency in HF band
+    u4_t frf = 868000000;
+    writeReg(RegFrfMsb, (u1_t)(frf>>16));
+    writeReg(RegFrfMid, (u1_t)(frf>> 8));
+    writeReg(RegFrfLsb, (u1_t)(frf>> 0));
+
+    // Launch Rx chain calibration for HF band 
+    writeReg(FSKRegImageCal, (readReg(FSKRegImageCal) & RF_IMAGECAL_IMAGECAL_MASK)|RF_IMAGECAL_IMAGECAL_START);
+    while((readReg(FSKRegImageCal) & RF_IMAGECAL_IMAGECAL_RUNNING) == RF_IMAGECAL_IMAGECAL_RUNNING) { ; }
+#endif /* CFG_sx1276mb1_board */
+
+    /* SF12/500KHz RX improvement (0x1d/0x19 choice): must match setting of LORARegInvertIQ */
+    writeReg(LORARegTimingInvert, 0x19);
+
+    opmode(OPMODE_SLEEP);
+
+    hal_enableIRQs();
+}
+
+// return next random byte derived from seed buffer
+// (buf[0] holds index of next byte to be returned)
+u1_t radio_rand1 () {
+    u1_t i = randbuf[0];
+    ASSERT( i != 0 );
+    if( i==16 ) {
+        os_aes(AES_ENC, randbuf, 16); // encrypt seed with any key
+        i = 0;
+    }
+    u1_t v = randbuf[i++];
+    randbuf[0] = i;
+    return v;
+}
+
+u1_t radio_rssi () {
+    hal_disableIRQs();
+    u1_t r = readReg(LORARegRssiValue);
+    hal_enableIRQs();
+    return r;
+}
+
+static const u2_t LORA_RXDONE_FIXUP[] = {
+    [FSK]  =     us2osticks(0), // (   0 ticks)
+    [SF7]  =     us2osticks(0), // (   0 ticks)
+    [SF8]  =  us2osticks(1648), // (  54 ticks)
+    [SF9]  =  us2osticks(3265), // ( 107 ticks)
+    [SF10] =  us2osticks(7049), // ( 231 ticks)
+    [SF11] = us2osticks(13641), // ( 447 ticks)
+    [SF12] = us2osticks(31189), // (1022 ticks)
+};
+
+// called by hal ext IRQ handler
+// (radio goes to stanby mode after tx/rx operations)
+void radio_irq_handler (u1_t dio) {
+    ostime_t now = os_getTime();
+    if( (readReg(RegOpMode) & OPMODE_LORA) != 0) { // LORA modem
+        u1_t flags = readReg(LORARegIrqFlags);
+        if( flags & IRQ_LORA_TXDONE_MASK ) {
+            // save exact tx time
+            LMIC.txend = now - us2osticks(43); // TXDONE FIXUP
+        } else if( flags & IRQ_LORA_RXDONE_MASK ) {
+            // save exact rx time
+            if(getBw(LMIC.rps) == BW125) {
+                now -= LORA_RXDONE_FIXUP[getSf(LMIC.rps)];
+            }
+            LMIC.rxtime = now;
+            // read the PDU and inform the MAC that we received something
+            LMIC.dataLen = (readReg(LORARegModemConfig1) & SX1272_MC1_IMPLICIT_HEADER_MODE_ON) ?
+                readReg(LORARegPayloadLength) : readReg(LORARegRxNbBytes);
+            // set FIFO read address pointer
+            writeReg(LORARegFifoAddrPtr, readReg(LORARegFifoRxCurrentAddr)); 
+            // now read the FIFO
+            readBuf(RegFifo, LMIC.frame, LMIC.dataLen);
+            // read rx quality parameters
+            LMIC.snr  = readReg(LORARegPktSnrValue); // SNR [dB] * 4
+            LMIC.rssi = readReg(LORARegPktRssiValue) - 125 + 64; // RSSI [dBm] (-196...+63)
+        } else if( flags & IRQ_LORA_RXTOUT_MASK ) {
+            // indicate timeout
+            LMIC.dataLen = 0;
+        }
+        // mask all radio IRQs
+        writeReg(LORARegIrqFlagsMask, 0xFF);
+        // clear radio IRQ flags
+        writeReg(LORARegIrqFlags, 0xFF);
+    } else { // FSK modem
+        u1_t flags1 = readReg(FSKRegIrqFlags1);
+        u1_t flags2 = readReg(FSKRegIrqFlags2);
+        if( flags2 & IRQ_FSK2_PACKETSENT_MASK ) {
+            // save exact tx time
+            LMIC.txend = now;
+        } else if( flags2 & IRQ_FSK2_PAYLOADREADY_MASK ) {
+            // save exact rx time
+            LMIC.rxtime = now;
+            // read the PDU and inform the MAC that we received something
+            LMIC.dataLen = readReg(FSKRegPayloadLength);
+            // now read the FIFO
+            readBuf(RegFifo, LMIC.frame, LMIC.dataLen);
+            // read rx quality parameters
+            LMIC.snr  = 0; // determine snr
+            LMIC.rssi = 0; // determine rssi
+        } else if( flags1 & IRQ_FSK1_TIMEOUT_MASK ) {
+            // indicate timeout
+            LMIC.dataLen = 0;
+        } else {
+            while(1);
+        }
+    }
+    // go from stanby to sleep
+    opmode(OPMODE_SLEEP);
+    // run os job (use preset func ptr)
+    os_setCallback(&LMIC.osjob, LMIC.osjob.func);
+}
+
+void os_radio (u1_t mode) {
+    hal_disableIRQs();
+    switch (mode) {
+      case RADIO_RST:
+        // put radio to sleep
+        opmode(OPMODE_SLEEP);
+        break;
+
+      case RADIO_TX:
+        // transmit frame now
+        starttx(); // buf=LMIC.frame, len=LMIC.dataLen
+        break;
+      
+      case RADIO_RX:
+        // receive frame now (exactly at rxtime)
+        startrx(RXMODE_SINGLE); // buf=LMIC.frame, time=LMIC.rxtime, timeout=LMIC.rxsyms
+        break;
+
+      case RADIO_RXON:
+        // start scanning for beacon now
+        startrx(RXMODE_SCAN); // buf=LMIC.frame
+        break;
+    }
+    hal_enableIRQs();
+}