AS3935.cpp

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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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*/

//	AS3935 MOD-1016 Lightning Sensor Arduino library
//	Written originally by Embedded Adventures


#include "Arduino.h"
#include "Wire.h"
#include "SPI.h"
#include "AS3935.h"

volatile bool displayingFrequency;
volatile sgn32 pulse = 0;
sgn32 cap_frequencies[16];

void pulseDetected() {
	if (displayingFrequency)
		pulse++;
}

void autoTuneCaps(uns8 irq) {
	int fdiv = mod1016.getDivisionRatio();
	Serial.println("Measuring frequency. Please wait...\n");
	freqPerTuneCaps(fdiv, irq);
	recommendTuning();
	mod1016.calibrateRCO();
	delay(1000);
}

sgn32 getFrequency(uns8 irq) {
	mod1016.writeRegister(DISP_LCO, 0x80);
	displayingFrequency = true;
	pulse = 0;
	attachInterrupt(digitalPinToInterrupt(irq), pulseDetected, RISING);
	delay(200);
	displayingFrequency = false;
	detachInterrupt(irq);
	mod1016.writeRegister(DISP_LCO, 0x00);
	return (pulse * 5);
}

void freqPerTuneCaps(uns16 fdiv, uns8 irq) {
	for (int i = 0; i < 16; i++) {
		mod1016.setTuneCaps(i);
		delay(2);
		/*Measure frequency 5x. Get average.
		If you want to use a slower aproach that measures frequency over a longer period of time, uncomment this section, 
		and comment out the other sgn32 freq line.
		
		sgn32 freq = 0;
		for (int i = 0; i < 5; i++) {
		  freq += getFrequency(irq);
		}
		freq = ((freq / 5) * fdiv) - 500000;
		
		/*Measure frequency in 1/5th of a second, multiply by 500000*/
		sgn32 freq = (getFrequency(irq) * fdiv) - 500000;

		cap_frequencies[i] = (freq < 0) ? -freq : freq;
		//Uncomment to print out frequnecy calculations
		/*
		Serial.print("TUNE CAPS = ");
		Serial.print(i);
		Serial.print("\tFrequency - 500k = ");
		Serial.println(cap_frequencies[i]);
		Serial.println();*/
	}
}

void recommendTuning() {
	int best = 0, next, current;
	for (int i = 1; i < 16; i++) {
		current = best;
		next = i;
		best = (cap_frequencies[next] < cap_frequencies[current]) ? next : best; 
	}
	//Serial.print("Best value for TUNE_CAPS - ");
	//Serial.println(best);
	//Serial.println("Setting TUNE_CAPS...");
	mod1016.setTuneCaps(best);
}

/*--------------------------------------------------------*/

void AS3935Class::init(uns8 irqPin) {
	_usingI2C = true;
	calibrateRCO();
	pinMode(irqPin, INPUT);
}

void AS3935Class::init(uns8 irqPin, uns8 csPin) {
	_usingI2C = false;
	_irq = irqPin;
	_cs = csPin;
	pinMode(_cs, OUTPUT);
	digitalWrite(_cs, HIGH);
	calibrateRCO();
	pinMode(_irq, INPUT);
	SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE2));
}

void AS3935Class::init(uns8 irqPin, uns8 clkPin, uns8 mosiPin, uns8 misoPin, uns8 csPin) {
	_usingI2C = false;
	_irq = irqPin;
	_clk = clkPin;
	_mosi = mosiPin;
	_miso = misoPin;
	_cs = csPin;
	
	pinMode(_clk, OUTPUT);
	pinMode(_mosi, OUTPUT);
	pinMode(_miso, INPUT);
	pinMode(_cs, OUTPUT);
	digitalWrite(_cs, HIGH);
	calibrateRCO();
	pinMode(_irq, INPUT);
	SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE2));
	
}

void AS3935Class::calibrateRCO() {
	if (_usingI2C) {
		Wire.beginTransmission(AS3935_ADDR);
		Wire.write(0x3D);
		Wire.write(0x96);
		Wire.endTransmission();
	}
	else {
		digitalWrite(_cs, LOW);
		SPI.transfer(AS3935_SPI_WRITE & 0x3D);
		SPI.transfer(0x96);
		digitalWrite(_cs, HIGH);
	}
	writeRegister(DISP_TRCO, (0x01 << 5));
	delay(2);
	writeRegister(DISP_TRCO, (0x00 << 5));
}

uns8 AS3935Class::readRegisterRaw(uns8 reg) {
	uns8 result;
	if (_usingI2C) {
		Wire.beginTransmission(AS3935_ADDR);
		Wire.write(reg);
		Wire.endTransmission(false);
		Wire.requestFrom(AS3935_ADDR, 1);
		if (Wire.available()) {
			result = Wire.read();
		}
	}
	else {
		reg &= 0x3F;
		reg |= AS3935_SPI_READ;
		digitalWrite(_cs, LOW);
		SPI.transfer(reg);
		result = SPI.transfer(0x00); 
		digitalWrite(_cs, HIGH);
	}
	return result;
}

uns8 AS3935Class::readRegister(uns8 reg, uns8 mask) {
	uns8 data = readRegisterRaw(reg);
	return (data & mask);
}

void AS3935Class::writeRegister(uns8 reg, uns8 mask, uns8 data) {
	uns8 currentReg = readRegisterRaw(reg);
	currentReg = currentReg & (~mask);
	data |= currentReg;
	if (_usingI2C) {
		Wire.beginTransmission(AS3935_ADDR);
		Wire.write(reg);
		Wire.write(data);
		Wire.endTransmission();
	}
	else {
		reg &= AS3935_SPI_WRITE;
		digitalWrite(_cs, LOW);
		SPI.transfer(reg);
		SPI.transfer(data);
		digitalWrite(_cs, HIGH);
	}
}

void AS3935Class::setIndoors() {
	writeRegister(AFE_GB, INDOORS);
}

void AS3935Class::setOutdoors() {
	writeRegister(AFE_GB, OUTDOORS);
}

void AS3935Class::setNoiseFloor(uns8 noise) {
	writeRegister(NOISE_FLOOR, (noise << 4));
}

void AS3935Class::setTuneCaps(uns8 tune) {
	writeRegister(TUNE_CAPS, tune);
	delay(2);
}

void AS3935Class::enableDisturbers() {
	writeRegister(MASK_DST, (0 << 5));
	delay(2);
}

void AS3935Class::disableDisturbers() {
	writeRegister(MASK_DST, (1 << 5));
	delay(2);	
}

uns8 AS3935Class::getNoiseFloor() {
	return (readRegister(NOISE_FLOOR) >> 4);
}

uns8 AS3935Class::getAFE() {
	return (readRegister(AFE_GB) >> 1);
}

uns8 AS3935Class::getTuneCaps() {
	return readRegister(TUNE_CAPS);
}

uns8 AS3935Class::getIRQ() {
	delay(2);
	return readRegister(IRQ_TBL);
}

uns8 AS3935Class::getLightDistance() {
	return readRegister(LGHT_DIST);
}

sgn16 AS3935Class::calculateDistance() {
	uns8 dist = getLightDistance();
	sgn16 km;		
	switch (dist) {
		case 0x3F:
			km = -1;
			break;
		case 0x28:
			km = 40;
			break;
		case 0x25:
			km = 37;
			break;
		case 0x22:
			km = 34;
			break;
		case 0x1F:
			km = 31;
			break;
		case 0x1B:
			km = 27;
			break;
		case 0x18:
			km = 24;
			break;
		case 0x14:
			km = 20;
			break;
		case 0x11:
			km = 17;
			break;
		case 0x0E:
			km = 14;
			break;
		case 0x0C:
			km = 12;
			break;
		case 0x0A:
			km = 10;
			break;
		case 0x08:
			km = 8;
			break;
		case 0x06:
			km = 6;
			break;
		case 0x05:
			km = 5;
			break;
		case 0x01:
			km = 0;
			break;
		default:
			km = 1;
	}
	return km;
}

sgn16 AS3935Class::getDivisionRatio() {
	uns8 fdiv = (readRegister(LCO_FDIV) >> 6);
	if (fdiv == 0)
		return 16;
	else if (fdiv == 1)
		return 32;
	else if (fdiv == 2) 
		return 64;
	else	
		return 128;
}

uns16 AS3935Class::getIntensity() {
	uns8 lsb, msb, mmsb;
	lsb = readRegisterRaw(0x04);
	msb = readRegisterRaw(0x05);
	mmsb = readRegisterRaw(0x06) & 0x1F;
	uns16 result = (uns16)lsb | ((uns16)msb << 8) | ((uns16)mmsb << 16);
	return result;
}

AS3935Class mod1016;