Akeru.cpp

/* Akeru.h - v4 [2016.07.29]
 * 
 * Copyleft Snootlab 2016 - inspired by TD1208 lib by IoTHerd (C) 2016
 *
 * Akeru is a library for Sigfox TD1208 use with the Arduino platform. 
 * The library is designed to use SoftwareSerial library for serial communication between TD1208 module and Arduino.
 * Current library coverage is:
 *	 - AT command 
 *	 - Sigfox payload transfer
 *	 - TD1208 temperature read
 *	 - TD1208 ID read
 *	 - TD1208 supply voltage read
 *	 - TD1208 hardware version read
 *	 - TD1208 firmware version read
 *	 - TD1208 power read
 *	 - TD1208 power set
 *   - TD1208 downlink request
 *   - Data conversion in hexadecimal
 */
 
#include "Akeru.h"

Akeru::Akeru(unsigned int rx, unsigned int tx)
{
	serialPort = new SoftwareSerial(rx, tx);
	_lastSend = -1;
}

void Akeru::echoOn()
{
	_cmdEcho = true;
}

void Akeru::echoOff()
{
	_cmdEcho = false;
}

bool Akeru::begin()
{
	// Let the modem warm up a bit
	delay(2000);
	_lastSend = -1;
	
	// Check TD1208 communication
	if (sendAT()) return true;
	else return false;
}

bool Akeru::isReady()
{
	// IMPORTANT WARNING. PLEASE READ BEFORE MODIFYING THE CODE
	//
	// The Sigfox network operates on public frequencies. To comply with
	// radio regulation, it can send radio data a maximum of 1% of the time
	// to leave room to other devices using the same frequencies.
	//
	// Sending a message takes about 6 seconds (it's sent 3 times for
	// redundancy purposes), meaning the interval between messages should
	// be 10 minutes.
	//
	// Also make sure your send rate complies with the restrictions set
	// by the particular subscription contract you have with your Sigfox
	// network operator.
	//
	// FAILING TO COMPLY WITH THESE CONSTRAINTS MAY CAUSE YOUR MODEM
	// TO BE BLOCKED BY YOUR SIFGOX NETWORK OPERATOR.
	//
	// You've been warned!
	
	unsigned long currentTime = millis();
    if(currentTime >= _lastSend && (currentTime - _lastSend) <= 600000) return false;
	else return true;
}

bool Akeru::sendAT()
{
	return sendATCommand(ATCOMMAND, ATCOMMAND_TIMEOUT, nullptr);
}

// Payload must be a String formatted in hexadecimal, 12 bytes max, use toHex()
bool Akeru::sendPayload(const String payload)
{
	if (!isReady()) return false; // prevent user from sending to many messages
	
	String message = (String) ATSIGFOXTX + payload;

	String data = "";
	if (sendATCommand(message, ATSIGFOXTX_TIMEOUT, &data))
	{
		if (_cmdEcho)
		{
			Serial.println(data);
		}
		_lastSend = millis();
		return true;
	}
	else
	{
		return false;
	}
}

bool Akeru::getTemperature(int *temperature)
{
	String data = "";
	if (sendATCommand(ATTEMPERATURE, ATCOMMAND_TIMEOUT, &data))
	{
		*temperature = data.toInt();
		return true;
	}
	else
	{
		return false;
	}
}



bool Akeru::getID(String *id)
{
	String data = "";
	if (sendATCommand(ATID, ATCOMMAND_TIMEOUT, &data))
	{
		*id = data;
		return true;
	}
	else
	{
		return false;
	}
}

bool Akeru::getVoltage(float *voltage)
{
	String data = "";
	if (sendATCommand(ATVOLTAGE, ATCOMMAND_TIMEOUT, &data))
	{
		*voltage = data.toFloat();
		return true;
	}
	else
	{
		return false;
	}
}

bool Akeru::getHardware(String *hardware)
{
	String data = "";
	if (sendATCommand(ATHARDWARE, ATCOMMAND_TIMEOUT, &data))
	{
		*hardware = data;
		return true;
	}
	else
	{
		return false;
	}
}

bool Akeru::getFirmware(String *firmware)
{
	String data = "";
	if (sendATCommand(ATFIRMWARE, ATCOMMAND_TIMEOUT, &data))
	{
		*firmware = data;
		return true;
	}
	else
	{
		return false;
	}
}

bool Akeru::getPower(int *power)
{	
	String message = (String) ATPOWER + '?';
	String data = "";
	if (sendATCommand(message, ATCOMMAND_TIMEOUT, &data))
	{
		*power = data.toInt();
		return true;
	}
	else
	{
		return false;
	}
}

// Power value: 0...14
bool Akeru::setPower(int power)
{
	String message = (String) ATPOWER + "=" + power;
	String data = "";
	if (sendATCommand(message, ATCOMMAND_TIMEOUT, &data))
	{
		Serial.println(data);
		return true;
	}
	else
	{
		return false;
	}
}

bool Akeru::receive(String *data)
{
	if (!isReady()) return false;
	
	if (sendATCommand(ATDOWNLINK, ATSIGFOXTX_TIMEOUT, data))
	{
		// Restart serial interface
		serialPort->begin(9600);
		delay(200);	
		serialPort->flush();
		serialPort->listen();
		
		// Read response 
		String response = "";
		
		unsigned int startTime = millis();
		volatile unsigned int currentTime = millis();
		volatile char rxChar = '\0';

		// RX management : two ways to break the loop
		// - Timeout
		// - Receive 
		do
		{
			if (serialPort->available() > 0)
			{
				rxChar = (char)serialPort->read();
				response.concat(rxChar);
			}
			currentTime = millis();
		}while(((currentTime - startTime) < ATDOWNLINK_TIMEOUT) && response.endsWith(DOWNLINKEND) == false);

		serialPort->end();
		if (_cmdEcho)
		{
			Serial.println(response);
		}
		
		// Now that we have the full answer we can look for the received bytes
		if (response.length() != 0)
		{
			// Search for transmission start
			int index = response.indexOf("=");
			// Get the chunk, it's 8 bytes long + separating spaces = 23 chars
			String chunk = response.substring(index, index+24);
			if (chunk.length() > 0)
			{
				// Remove the spaces
				chunk.replace(" ", "");
				*data = chunk;
				return true;
			}
		}
	}
	else 
	{
		return false;
	}
}

String Akeru::toHex(int i)
{
	byte * b = (byte*) & i;
	
	String bytes = "";
	for (int j=0; j<2; j++)
	{
		if (b[j] <= 0xF) // single char
		{
			bytes.concat("0"); // add a "0" to make sure every byte is read correctly
		}
		bytes.concat(String(b[j], 16));
	}
	return bytes;
}

String Akeru::toHex(unsigned int ui)
{
	byte * b = (byte*) & ui;
	
	String bytes = "";
	for (int i=0; i<2; i++)
	{
		if (b[i] <= 0xF) // single char
		{
			bytes.concat("0"); // add a "0" to make sure every byte is read correctly
		}
		bytes.concat(String(b[i], 16));
	}
	return bytes;
}

String Akeru::toHex(long l)
{
	byte * b = (byte*) & l;
	
	String bytes = "";
	for (int i=0; i<4; i++)
	{
		if (b[i] <= 0xF) // single char
		{
			bytes.concat("0"); // add a "0" to make sure every byte is read correctly
		}
		bytes.concat(String(b[i], 16));
	}
	return bytes;
}

String Akeru::toHex(unsigned long ul)
{
	byte * b = (byte*) & ul;
	
	String bytes = "";
	for (int i=0; i<4; i++)
	{
		if (b[i] <= 0xF) // single char
		{
			bytes.concat("0"); // add a "0" to make sure every byte is read correctly
		}
		bytes.concat(String(b[i], 16));
	}
	return bytes;
}

String Akeru::toHex(float f)
{
	byte * b = (byte*) & f;

	String bytes = "";
	for (int i=0; i<4; i++)
	{
		if (b[i] <= 0xF) // single char
		{
			bytes.concat("0"); // add a "0" to make sure every byte is read correctly
		}
		bytes.concat(String(b[i], 16));
	}
	return bytes;
}

String Akeru::toHex(double d)
{
	byte * b = (byte*) & d;

	String bytes = "";
	for (int i=0; i<4; i++)
	{
		if (b[i] <= 0xF) // single char
		{
			bytes.concat("0"); // add a "0" to make sure every byte is read correctly
		}
		bytes.concat(String(b[i], 16));
	}
	return bytes;
}

String Akeru::toHex(char c)
{
	byte *b = (byte*) & c;
	
	String bytes = "";
	if (b[0] <= 0xF) // single char
	{
		bytes.concat("0"); // add a "0" to make sure every byte is read correctly
	}
	bytes.concat(String(b[0], 16));
	return bytes;
}

String Akeru::toHex(char *c, int length)
{
	byte * b = (byte*) c;
	
	String bytes = "";
	for (int i=0; i<length; i++)
	{
		if (b[i] <= 0xF) // single char
		{
			bytes.concat("0"); // add a "0" to make sure every byte is read correctly
		}
		bytes.concat(String(b[i], 16));
	}
	return bytes;
}

bool Akeru::sendATCommand(const String command, const int timeout, String *dataOut)
{
	// Start serial interface
	serialPort->begin(9600);
	delay(200);	
	serialPort->flush();
	serialPort->listen();

	// Add CRLF to the command
	String ATCommand = "";
	ATCommand.concat(command);
	ATCommand.concat("\r\n");

	if (_cmdEcho)
	{
		Serial.print((String)"\n>> " + ATCommand);
	}

	// Send the command : need to write/read char by char because of echo
	for (int i = 0; i < ATCommand.length(); ++i)
	{
		serialPort->print(ATCommand.c_str()[i]);
		serialPort->read();
	}
	if (_cmdEcho)
	{
		Serial.print("<< ");
	}
	
	// Read response 
	String response = "";
	
	unsigned int startTime = millis();
	volatile unsigned int currentTime = millis();
	volatile char rxChar = '\0';

	// RX management : two ways to break the loop
	// - Timeout
	// - Receive 
	do
	{
		if (serialPort->available() > 0)
		{
			rxChar = (char)serialPort->read();
			response.concat(rxChar);
		}

		currentTime = millis();
	}while(((currentTime - startTime) < timeout) && response.endsWith(ATOK) == false);

	serialPort->end();
	
	if (_cmdEcho)
	{
		Serial.println(response);
	}

	// Split the response
	int index = 0;
	String firstData = "";
	String secondData = "";

	if (response.length() != 0)
	{
		// Split CRLF
		do
		{
			// Save previous index
			int previous = index;

			// Get next index
			index = response.indexOf("\r\n", index);

			// Check that index change
			if (previous != index)
			{
				// Get the chunk
				String chunk = response.substring(previous+1, index);
				if (chunk.length() > 0)
				{
					// Remove \r\n 
					chunk.replace("\r\n", "");
					
					if (firstData != "")
					{
						secondData = chunk;
					}
					else if (firstData == "" && secondData == "")
					{
						firstData = chunk;
					}
					else
					{
						Serial.println("ERROR on rx frame");
						return false;
					}
				}
			}

			// Increment index
			if (index >= 0) index++;
		
		} while (index < response.length() && index >= 0);
	}
	else
	{
		return false;
	}

	// Check if we have data on the first string and OK on second = data + OK
	if (firstData != "" && secondData == ATOK)
	{
		*dataOut = firstData;
		return true;
	}
	// Check if we have only an OK
	else if (firstData == ATOK && secondData == "")
	{
		return true;
	}
	else
	{
		Serial.println("Wrong AT response");
		return false;
	}
}