LoRa_APRS_Tracker/src/LoRa_APRS_Tracker.cpp

#include <Arduino.h>
#include <LoRa.h>
#include <APRS-Decoder.h>
#include <TinyGPS++.h>

#include "settings.h"
#include "display.h"
#include "pins.h"
#include <TimeLib.h>

#ifdef TTGO_T_Beam_V1_0
#include <axp20x.h>
void setup_axp();
AXP20X_Class axp;
#endif

HardwareSerial ss(1);
TinyGPSPlus gps;
void setup_gps();
String create_lat_aprs(RawDegrees lat);
String create_long_aprs(RawDegrees lng);

void setup_lora();

static time_t nowTimeStamp = -1;
static time_t nextBeaconTimeStamp = -1;
static tmElements_t nextBeaconStruct;
static bool send_update = true;

// cppcheck-suppress unusedFunction
void setup()
{
	Serial.begin(115200);
	setup_display();
	
	delay(500);
	Serial.println("[INFO] LoRa APRS Tracker by OE5BPA (Peter Buchegger)");
	show_display("OE5BPA", "LoRa APRS Tracker", "by Peter Buchegger", 2000);

#ifdef TTGO_T_Beam_V1_0
	setup_axp();
#endif
	setup_gps();
	setup_lora();
	
	delay(500);
}

String toDoubleInt(int number)
{
	if(number < 10)
	{
		return "0" + String(number);
	}
	return String(number);
}

// cppcheck-suppress unusedFunction
void loop()
{
	while (ss.available() > 0)
	{
		char c = ss.read();
		//Serial.print(c);
		gps.encode(c);
	}

	bool gps_time_update = false;
	if(gps.time.isUpdated())
	{
		gps_time_update = true;
	}

	if(gps.time.isValid())
	{
		setTime(gps.time.hour(),gps.time.minute(),gps.time.second(),gps.date.day(),gps.date.month(),gps.date.year());
		nowTimeStamp = now();

		if (nextBeaconTimeStamp <= nowTimeStamp || nextBeaconTimeStamp == -1)
		{
			send_update = true;
		}
	}

	if(send_update && gps.location.isValid() && gps.location.isUpdated())
	{
		nextBeaconTimeStamp = nowTimeStamp + (BEACON_TIMEOUT * 60);
		breakTime(nextBeaconTimeStamp, nextBeaconStruct);
		send_update = false;

		APRSMessage msg;
		msg.setSource(CALL);
		msg.setDestination("APLT0");
		String lat = create_lat_aprs(gps.location.rawLat());
		String lng = create_long_aprs(gps.location.rawLng());
		msg.getAPRSBody()->setData(String("=") + lat + SYMBOL_OVERLAY + lng + SYMBOL_CODE + BEACON_MESSAGE);
		String data = msg.encode();
		Serial.println(data);
		show_display("<< TX >>", data);
		LoRa.beginPacket();
		// Header:
		LoRa.write('<');
		LoRa.write(0xFF);
		LoRa.write(0x01);
		// APRS Data:
		LoRa.write((const uint8_t *)data.c_str(), data.length());
		LoRa.endPacket();
	}

	if(gps_time_update)
	{
		#ifdef TTGO_T_Beam_V1_0
		char batteryVoltage[6];
		dtostrf(axp.getBattVoltage()/1000, 1, 2, batteryVoltage);

		char batteryChargeCurrent[6];
		String batteryIndicator;
		if(axp.isChargeing())
		{
			dtostrf(axp.getBattChargeCurrent(), 3, 0, batteryChargeCurrent);
			batteryIndicator = "+";
		}
		else
		{
			dtostrf(axp.getBattDischargeCurrent(), 3, 0, batteryChargeCurrent);
			batteryIndicator = "-";
		}
		#endif

		show_display(CALL,
			toDoubleInt(gps.date.day())  + String(".") + toDoubleInt(gps.date.month())  + String(".") + gps.date.year() + String(" ") + toDoubleInt(gps.time.hour()) + String(":") + toDoubleInt(gps.time.minute()) + String(":") + toDoubleInt(gps.time.second()),
			String("Sats: ") + gps.satellites.value() + String(" HDOP: ") + gps.hdop.hdop(),
			String("Nxt Bcn: ") + toDoubleInt(nextBeaconStruct.Hour) + String(":") + toDoubleInt(nextBeaconStruct.Minute),
			#ifdef TTGO_T_Beam_V1_0
			String("Bat: ") + batteryVoltage + String("V ") + batteryIndicator + batteryChargeCurrent + String("mA"),
			#endif
			);
	}


	if(millis() > 5000 && gps.charsProcessed() < 10)
	{
		Serial.println("No GPS detected!");
	}
}

#ifdef TTGO_T_Beam_V1_0
void setup_axp()
{
	Wire.begin(SDA, SCL);
	if (!axp.begin(Wire, AXP192_SLAVE_ADDRESS))
	{
		Serial.println("LoRa-APRS / Init / AXP192 Begin PASS");
	} else {
		Serial.println("LoRa-APRS / Init / AXP192 Begin FAIL");
	}
	axp.setPowerOutPut(AXP192_LDO2, AXP202_ON);  // LORA
	axp.setPowerOutPut(AXP192_LDO3, AXP202_ON);  // GPS
	axp.setPowerOutPut(AXP192_DCDC1, AXP202_ON); // OLED
	axp.setDCDC1Voltage(3300);

	/*Enable AXP ADC function*/
    axp.adc1Enable(AXP202_BATT_CUR_ADC1 |
                   AXP202_BATT_VOL_ADC1,
                   true);
}
#endif

void setup_lora()
{
	Serial.println("[INFO] Set SPI pins!");
	SPI.begin(LORA_SCK, LORA_MISO, LORA_MOSI, LORA_CS);
	LoRa.setPins(LORA_CS, LORA_RST, LORA_IRQ);
	Serial.println("[INFO] Set LoRa pins!");

	long freq = 433775000;
	Serial.print("[INFO] frequency: ");
	Serial.println(freq);
	if (!LoRa.begin(freq)) {
		Serial.println("[ERROR] Starting LoRa failed!");
		show_display("ERROR", "Starting LoRa failed!");
		while (1);
	}
	LoRa.setSpreadingFactor(12);
	LoRa.setSignalBandwidth(125E3);
	LoRa.setCodingRate4(5);
	LoRa.enableCrc();

	LoRa.setTxPower(20);
	Serial.println("[INFO] LoRa init done!");
	show_display("INFO", "LoRa init done!", 2000);
}

void setup_gps()
{
	ss.begin(9600, SERIAL_8N1, GPS_TX, GPS_RX);
}

String create_lat_aprs(RawDegrees lat)
{
	char str[20];
	char n_s = 'N';
	if(lat.negative)
	{
		n_s = 'S';
	}
	sprintf(str, "%02d%05.2f%c", lat.deg, lat.billionths / 1000000000.0 * 60.0, n_s);
	String lat_str(str);
	return lat_str;
}

String create_long_aprs(RawDegrees lng)
{
	char str[20];
	char e_w = 'E';
	if(lng.negative)
	{
		e_w = 'W';
	}
	sprintf(str, "%03d%05.2f%c", lng.deg, lng.billionths / 1000000000.0 * 60.0, e_w);
	String lng_str(str);
	return lng_str;
}