wayne roberts / Mbed OS alarm_master

Alarm generator, transmitter side

Dependencies:   sx12xx_hal

radio chip selection

Radio chip driver is not included, allowing choice of radio device.
If you're using SX1272 or SX1276, then import sx127x driver into your program.
if you're using SX1261 or SX1262, then import sx126x driver into your program.
if you're using SX1280, then import sx1280 driver into your program.
If you're using NAmote72 or Murata discovery, then you must import only sx127x driver.

This is transmitter project; Receiver side is Alarm Slave project.
This project generates alarm (transmits) from grounding certain pins.
To find the actual pins used, refer to the code where pin[A-D] is declared as DigitalIn.

Alarm message is sent N times with future timestamp indicating when alarm is to occur. This accommodates dropped packets, resulting in alarm occurring when as few as 1 packet is received.

main.cpp

Committer:
dudmuck
Date:
2018-01-26
Revision:
3:d8b57eca8c45
Parent:
2:0b7620bda2c9
Child:
4:19056d9707ef

File content as of revision 3:d8b57eca8c45:

#include "sx127x_lora.h"
 
#ifdef TARGET_DISCO_L072CZ_LRWAN1

    SPI spi(PA_7, PA_6, PB_3); // mosi, miso, sclk
    //           dio0, dio1,  nss,  spi,  rst
    SX127x radio(PB_4, PB_1, PA_15, spi, PC_0);
    
    #define CRF1    PA_1
    #define CRF2    PC_2
    #define CRF3    PC_1
    DigitalOut Vctl1(CRF1);
    DigitalOut Vctl2(CRF2);
    DigitalOut Vctl3(CRF3);    
    
    void rfsw_callback()
    {
        if (radio.RegOpMode.bits.Mode == RF_OPMODE_TRANSMITTER) {
            Vctl1 = 0;        
            if (radio.RegPaConfig.bits.PaSelect) {
                Vctl2 = 0;
                Vctl3 = 1;                        
            } else {
                Vctl2 = 1;
                Vctl3 = 0;            
            }
        } else {
            if (radio.RegOpMode.bits.Mode == RF_OPMODE_RECEIVER || radio.RegOpMode.bits.Mode == RF_OPMODE_RECEIVER_SINGLE)
                Vctl1 = 1;
            else
                Vctl1 = 0;
            
            Vctl2 = 0;
            Vctl3 = 0;        
        }
    }    
    
    DigitalIn pinA(PB_12);
    DigitalIn pinB(PB_13);
    DigitalIn pinC(PB_14);
    DigitalIn pinD(PB_15);    
#else
    SPI spi(D11, D12, D13); // mosi, miso, sclk
    //           dio0, dio1, nss, spi, rst
    SX127x radio(  D2,   D3, D10, spi, A0); // sx1276 arduino shield
     
    DigitalInOut rfsw(A4);    // for SX1276 arduino shield
     
    void rfsw_callback()
    {
        if (radio.RegOpMode.bits.Mode == RF_OPMODE_TRANSMITTER) {
            rfsw = 1;
        } else {
            rfsw = 0;
        }
    }
    
    DigitalIn pinA(PC_3);
    DigitalIn pinB(PC_2);
    DigitalIn pinC(PC_6);
    DigitalIn pinD(PC_8);
#endif /* !TARGET_DISCO_L072CZ_LRWAN1 */

/**********************************************************************/

SX127x_lora lora(radio);
Timer t;
#define CMD_PINA       0x02
#define CMD_PINB       0x03
#define CMD_PINC       0x06
#define CMD_PIND       0x08

static uint16_t crc_ccitt( uint8_t *buffer, uint16_t length )
{
    // The CRC calculation follows CCITT
    const uint16_t polynom = 0x1021;
    // CRC initial value
    uint16_t crc = 0x0000;

    if( buffer == NULL )
    {
        return 0;
    }

    for( uint16_t i = 0; i < length; ++i )
    {
        crc ^= ( uint16_t ) buffer[i] << 8;
        for( uint16_t j = 0; j < 8; ++j )
        {
            crc = ( crc & 0x8000 ) ? ( crc << 1 ) ^ polynom : ( crc << 1 );
        }
    }

    return crc;
}

void transmit(unsigned target, uint8_t cmd)
{
    unsigned t_diff;
    uint16_t crc;

    radio.tx_buf[0] = cmd;
    t_diff = target - t.read_us();
    radio.tx_buf[1] = t_diff >> 24;
    radio.tx_buf[2] = t_diff >> 16;
    radio.tx_buf[3] = t_diff >> 8;
    radio.tx_buf[4] = t_diff & 0xff;
    crc = crc_ccitt(radio.tx_buf, 5);
    radio.tx_buf[5] = crc >> 8;
    radio.tx_buf[6] = crc & 0xff;


    lora.start_tx(lora.RegPayloadLength);   /* begin transmission */

    while (lora.service() != SERVICE_TX_DONE) {  /* wait for transmission to complete */
    }

    printf("t_diff:%u crc:%04x\r\n", t_diff, crc);
}

#define TARGET_LATENCY      2000000
void send_alarm(uint8_t cmd)
{
    int i;
    unsigned target = t.read_us() + TARGET_LATENCY;
    printf("send_alarm() %u\n", target);

    for (i = 0; i < 5; i++) {
        transmit(target, cmd);
        wait(0.1);
    }
}

void debounce(DigitalIn* pin, uint8_t cmd)
{
    if (!pin->read()) {
        int i;
        for (i = 0; i < 5; i++) {
            wait(0.01);
            if (pin->read()) {
                printf("trans\r\n");
                break;
            }
        }
        if (i == 5)
            send_alarm(cmd);

        while (!pin->read())
            ;
    }
}

void cmd_op(int dbm)
{
    int i = dbm;
    RegPdsTrim1_t pds_trim;
    uint8_t adr;
    if (radio.type == SX1276)
        adr = REG_PDSTRIM1_SX1276;
    else
        adr = REG_PDSTRIM1_SX1272;
       
    pds_trim.octet = radio.read_reg(adr);   

    if (radio.RegPaConfig.bits.PaSelect) {
        /* PABOOST used: +2dbm to +17, or +20 */
        if (i == 20) {
            printf("+20dBm PADAC bias\r\n");
            i -= 3;
            pds_trim.bits.prog_txdac = 7;
            radio.write_reg(adr, pds_trim.octet);
        }
        if (i > 1)
                radio.RegPaConfig.bits.OutputPower = i - 2;
    } else {
        /* RFO used: -1 to +14dbm */
        if (i < 15)
            radio.RegPaConfig.bits.OutputPower = i + 1;
    }
    radio.write_reg(REG_PACONFIG, radio.RegPaConfig.octet);

    radio.RegPaConfig.octet = radio.read_reg(REG_PACONFIG);
    if (radio.RegPaConfig.bits.PaSelect) {
        printf("PA_BOOST ");
        dbm = radio.RegPaConfig.bits.OutputPower + pds_trim.bits.prog_txdac - 2;
    } else {
        printf("RFO ");
        dbm = radio.RegPaConfig.bits.OutputPower - 1;
    }
    printf("OutputPower:%ddBm\r\n", dbm);
}

int main()
{
    printf("\r\nreset-tx\r\n");
    t.start();

    pinA.mode(PullUp);
    pinB.mode(PullUp);
    pinC.mode(PullUp);
    pinD.mode(PullUp);

    radio.rf_switch = rfsw_callback;
    
    radio.set_frf_MHz(910.8);
    lora.enable();
    lora.setBw_KHz(500);
    lora.setSf(11);
    
    radio.RegPaConfig.octet = radio.read_reg(REG_PACONFIG);
#ifdef TARGET_DISCO_L072CZ_LRWAN1
    radio.RegPaConfig.bits.PaSelect = 1;
#else    
    /* RFO or PABOOST choice:
     * SX1276 shield: RFO if using 900MHz, or PA_BOOST if using 433MHz
     */
    rfsw.input();
    if (rfsw.read()) {
        printf("LAS\r\n");
        /* LAS HF=PA_BOOST  LF=RFO */
        if (radio.HF)
            radio.RegPaConfig.bits.PaSelect = 1;
        else
            radio.RegPaConfig.bits.PaSelect = 0;
        cmd_op(20);
    } else {
        /* MAS shield board, only RFO TX */
        radio.RegPaConfig.bits.PaSelect = 0;
        printf("MAS\r\n");
        cmd_op(14);
    }
    rfsw.output();
#endif /* !TARGET_DISCO_L072CZ_LRWAN1 */
    radio.write_reg(REG_PACONFIG, radio.RegPaConfig.octet);
                
    /* constant payload length */
    lora.RegPayloadLength = 7;
    radio.write_reg(REG_LR_PAYLOADLENGTH, lora.RegPayloadLength);

    for (;;) {       
        debounce(&pinA, CMD_PINA);
        debounce(&pinB, CMD_PINB);
        debounce(&pinC, CMD_PINC);
        debounce(&pinD, CMD_PIND);
    } // ..for (;;)
}