ESP32-PaxCounter/src/lorawan.cpp

// Basic Config
#include "globals.h"

// LMIC-Arduino LoRaWAN Stack
#include "loraconf.h"
#include <lmic.h>
#include <hal/hal.h>

#ifdef MCP_24AA02E64_I2C_ADDRESS
    #include <Wire.h> // Needed for 24AA02E64, does not hurt anything if included and not used
#endif

// Local logging Tag
static const char TAG[] = "lora";

// functions defined in rcommand.cpp
void rcommand(uint8_t cmd, uint8_t arg);
void switch_lora(uint8_t sf, uint8_t tx);

// DevEUI generator using devices's MAC address
void gen_lora_deveui(uint8_t *pdeveui) {
    uint8_t *p = pdeveui, dmac[6];
    int i = 0;
    esp_efuse_mac_get_default(dmac);
    // deveui is LSB, we reverse it so TTN DEVEUI display 
    // will remain the same as MAC address
    // MAC is 6 bytes, devEUI 8, set first 2 ones 
    // with an arbitrary value
    *p++ = 0xFF;
    *p++ = 0xFE;
    // Then next 6 bytes are mac address reversed
    for ( i=0; i<6 ; i++) {
        *p++ = dmac[5-i];
    }
}

// Function to do a byte swap in a byte array
void RevBytes(unsigned char* b, size_t c)
{
  u1_t i;
  for (i = 0; i < c / 2; i++)
  { unsigned char t = b[i];
    b[i] = b[c - 1 - i];
    b[c - 1 - i] = t; }
}

void get_hard_deveui(uint8_t *pdeveui) {
    // read DEVEUI from Microchip 24AA02E64 2Kb serial eeprom if present
#ifdef MCP_24AA02E64_I2C_ADDRESS
    uint8_t i2c_ret;
    // Init this just in case, no more to 100KHz
    Wire.begin(OLED_SDA, OLED_SCL, 100000);
    Wire.beginTransmission(MCP_24AA02E64_I2C_ADDRESS);
    Wire.write(MCP_24AA02E64_MAC_ADDRESS); 
    i2c_ret = Wire.endTransmission();
    // check if device seen on i2c bus
    if (i2c_ret == 0) {
        char deveui[32]="";
        uint8_t data;
        Wire.beginTransmission(MCP_24AA02E64_I2C_ADDRESS);
        Wire.write(MCP_24AA02E64_MAC_ADDRESS); 
        Wire.requestFrom(MCP_24AA02E64_I2C_ADDRESS, 8);
        while (Wire.available()) {
            data = Wire.read();
            sprintf(deveui+strlen(deveui), "%02X ", data);
            *pdeveui++ = data;
        }
        i2c_ret = Wire.endTransmission();
        ESP_LOGI(TAG, "Serial EEPROM 24AA02E64 found, read DEVEUI %s", deveui);
    } else {
        ESP_LOGI(TAG, "Serial EEPROM 24AA02E64 not found ret=%d", i2c_ret);
    }
    // Set back to 400KHz to speed up OLED
    Wire.setClock(400000);
#endif // MCP 24AA02E64    
}

#ifdef VERBOSE

// Display a key
void printKey(const char * name, const uint8_t * key, uint8_t len, bool lsb) {
  const uint8_t * p ;
  char keystring[len+1] = "", keybyte[3];
  for (uint8_t i=0; i<len ; i++) {
     p = lsb ? key+len-i-1 : key+i;
     sprintf(keybyte, "%02X", * p);
     strncat(keystring, keybyte, 2);
    }
  ESP_LOGI(TAG, "%s: %s", name, keystring);
}

// Display OTAA keys
void printKeys(void) {
	// LMIC may not have used callback to fill 
	// all EUI buffer so we do it here to a temp
	// buffer to be able to display them
	uint8_t buf[32];
	os_getDevEui((u1_t*) buf);
	printKey("DevEUI", buf, 8, true);
	os_getArtEui((u1_t*) buf);
	printKey("AppEUI", buf, 8, true);
	os_getDevKey((u1_t*) buf);
	printKey("AppKey", buf, 16, false);
}

#endif // VERBOSE

void do_send(osjob_t* j){

    // Check if there is a pending TX/RX job running
    if (LMIC.opmode & OP_TXRXPEND) {
        ESP_LOGI(TAG, "LoRa busy, rescheduling");
        sprintf(display_lmic, "LORA BUSY");
        goto end;
    }

    // prepare payload with sum of unique WIFI MACs seen
    static uint8_t mydata[4];
  
    mydata[0] = (macs_wifi & 0xff00) >> 8;
    mydata[1] = macs_wifi  & 0xff;
    
    if (cfg.blescan) {
        // append sum of unique BLE MACs seen to payload
        mydata[2] = (macs_ble & 0xff00) >> 8;
        mydata[3] = macs_ble  & 0xff; 
    } else {
        mydata[2] = 0;
        mydata[3] = 0;
    }

    // Prepare upstream data transmission at the next possible time.
    LMIC_setTxData2(COUNTERPORT, mydata, sizeof(mydata), (cfg.countermode & 0x02));
    ESP_LOGI(TAG, "%d bytes queued to send", sizeof(mydata));
    sprintf(display_lmic, "PACKET QUEUED");
    
    #ifdef HAS_GPS
        if (cfg.gpsmode && gps.location.isValid()) {
            gps_read();
            LMIC_setTxData2(GPSPORT, (byte*)&gps_status, sizeof(gps_status), (cfg.countermode & 0x02));
            ESP_LOGI(TAG, "lat=%f / lon=%f | Sats=%u | HDOP=%u | Alti=%u", gps_status.latitude / 1000000, gps_status.longitude / 1000000, gps_status.satellites, gps_status.hdop, gps_status.altitude);
        }
    #endif
    
    // clear counter if not in cumulative counter mode
    if (cfg.countermode != 1) {
        reset_counters();                       // clear macs container and reset all counters
        reset_salt();                           // get new salt for salting hashes
        ESP_LOGI(TAG, "Counter cleared (countermode = %d)", cfg.countermode);
    }

    // Schedule next transmission
    end:
    os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(cfg.sendcycle * 2), do_send);

} // do_send()

void onEvent (ev_t ev) {
    char buff[24]="";

    switch(ev) {
        case EV_SCAN_TIMEOUT:   strcpy_P(buff, PSTR("SCAN TIMEOUT"));   break;
        case EV_BEACON_FOUND:   strcpy_P(buff, PSTR("BEACON FOUND"));   break;
        case EV_BEACON_MISSED:  strcpy_P(buff, PSTR("BEACON MISSED")); break;
        case EV_BEACON_TRACKED: strcpy_P(buff, PSTR("BEACON TRACKED")); break;
        case EV_JOINING:        strcpy_P(buff, PSTR("JOINING"));        break;
        case EV_LOST_TSYNC:     strcpy_P(buff, PSTR("LOST TSYNC"));     break;
        case EV_RESET:          strcpy_P(buff, PSTR("RESET"));          break;
        case EV_RXCOMPLETE:     strcpy_P(buff, PSTR("RX COMPLETE"));    break;
        case EV_LINK_DEAD:      strcpy_P(buff, PSTR("LINK DEAD"));      break;
        case EV_LINK_ALIVE:     strcpy_P(buff, PSTR("LINK ALIVE"));     break;
        case EV_RFU1:           strcpy_P(buff, PSTR("RFUI"));           break;
        case EV_JOIN_FAILED:    strcpy_P(buff, PSTR("JOIN FAILED"));    break;
        case EV_REJOIN_FAILED:  strcpy_P(buff, PSTR("REJOIN FAILED"));  break;
        
        case EV_JOINED:

            strcpy_P(buff, PSTR("JOINED"));
            sprintf(display_lora, " "); // clear previous lmic status message from display

            // Disable link check validation (automatically enabled
            // during join, but not supported by TTN at this time).  -> do we need this?
           // LMIC_setLinkCheckMode(0);
            
            // set data rate adaptation
            LMIC_setAdrMode(cfg.adrmode);
            // Set data rate and transmit power (note: txpower seems to be ignored by the library)
            switch_lora(cfg.lorasf,cfg.txpower);
            
            // show effective LoRa parameters after join
            ESP_LOGI(TAG, "ADR=%d, SF=%d, TXPOWER=%d", cfg.adrmode, cfg.lorasf, cfg.txpower);
            break;

        case EV_TXCOMPLETE:

            strcpy_P(buff, (LMIC.txrxFlags & TXRX_ACK) ? PSTR("RECEIVED ACK") : PSTR("TX COMPLETE")); 
            sprintf(display_lora, " "); // clear previous lmic status message from display
            
            if (LMIC.dataLen) {
                ESP_LOGI(TAG, "Received %d bytes of payload, RSSI %d SNR %d", LMIC.dataLen, LMIC.rssi, (signed char)LMIC.snr / 4);
                // LMIC.snr = SNR twos compliment [dB] * 4
                // LMIC.rssi = RSSI [dBm] (-196...+63)
                sprintf(display_lora, "RSSI %d SNR %d", LMIC.rssi, (signed char)LMIC.snr / 4 );

                // check if payload received on command port, then call remote command interpreter
                if ( (LMIC.txrxFlags & TXRX_PORT) && (LMIC.frame[LMIC.dataBeg-1] == RCMDPORT ) ) {
                    // caution: buffering LMIC values here because rcommand() can modify LMIC.frame
                    unsigned char* buffer = new unsigned char[MAX_LEN_FRAME];
                    memcpy(buffer, LMIC.frame, MAX_LEN_FRAME); //Copy data from cfg to char*
                    int i, k = LMIC.dataBeg, l = LMIC.dataBeg+LMIC.dataLen-2;
                    for (i=k; i<=l; i+=2) {
                        rcommand(buffer[i], buffer[i+1]);
                    }
                    delete[] buffer; //free memory
                }
            }
            break;

        default: sprintf_P(buff, PSTR("UNKNOWN EVENT %d"), ev);      break;
    }

    // Log & Display if asked
    if (*buff) {
        ESP_LOGI(TAG, "EV_%s", buff);
        sprintf(display_lmic, buff);
    }
 
} // onEvent()