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radio.c
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radio.c
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/*******************************************************************************
* 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 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 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];
#ifdef CFG_sx1276_radio
#define LNA_RX_GAIN (0x20|0x1)
#elif 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) {
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 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)
uint64_t frf = ((uint64_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 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;
}
writeReg(RegPaConfig, (u1_t)(0x80|(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);
#if LMIC_DEBUG_LEVEL > 0
u1_t sf = getSf(LMIC.rps) + 6; // 1 == SF7
u1_t bw = getBw(LMIC.rps);
u1_t cr = getCr(LMIC.rps);
lmic_printf("%lu: TXMODE, freq=%lu, len=%d, SF=%d, BW=%d, CR=4/%d, IH=%d\n",
os_getTime(), LMIC.freq, LMIC.dataLen, sf,
bw == BW125 ? 125 : (bw == BW250 ? 250 : 500),
cr == CR_4_5 ? 5 : (cr == CR_4_6 ? 6 : (cr == CR_4_7 ? 7 : 8)),
getIh(LMIC.rps)
);
#endif
}
// 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_TABLE(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);
#if !defined(DISABLE_INVERT_IQ_ON_RX)
// use inverted I/Q signal (prevent mote-to-mote communication)
writeReg(LORARegInvertIQ, readReg(LORARegInvertIQ)|(1<<6));
#endif
// 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, ~TABLE_GET_U1(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);
}
#if LMIC_DEBUG_LEVEL > 0
if (rxmode == RXMODE_RSSI) {
lmic_printf("RXMODE_RSSI\n");
} else {
u1_t sf = getSf(LMIC.rps) + 6; // 1 == SF7
u1_t bw = getBw(LMIC.rps);
u1_t cr = getCr(LMIC.rps);
lmic_printf("%lu: %s, freq=%lu, SF=%d, BW=%d, CR=4/%d, IH=%d\n",
os_getTime(),
rxmode == RXMODE_SINGLE ? "RXMODE_SINGLE" : (rxmode == RXMODE_SCAN ? "RXMODE_SCAN" : "UNKNOWN_RX"),
LMIC.freq, sf,
bw == BW125 ? 125 : (bw == BW250 ? 250 : 500),
cr == CR_4_5 ? 5 : (cr == CR_4_6 ? 6 : (cr == CR_4_7 ? 7 : 8)),
getIh(LMIC.rps)
);
}
#endif
}
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 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 */
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_TABLE(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 LMIC_DEBUG_LEVEL > 1
lmic_printf("%lu: irq: dio: 0x%x flags: 0x%x\n", now, dio, flags);
#endif
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 -= TABLE_GET_U2(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 {
ASSERT(0);
}
}
// 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();
}