M6E-Nano and Photon Red Board (Which Serial)

Greetings all,

I am working on something interesting here with the M6E-Nano and thought why not try to integrate with a Particle Device?

It just so happens that I had a Sparkfun Photon RedBoard Laying around which is swell because the RFID shield fits just right! I did a little digging through the datasheet and found that the Nano communicates on 3.3v (not 5v as I thought). So I took the Sparkfun Library and “Ported” it to the Build.Particle IDE. See code below as I am sure there are some mistakes.

So the question here is, which serial do I use? I see the RX/TX pins are in the same spot on the shield and RedBoard. There is a HW/SW switch on the RFID shield. The Arduino Library calls for the use of SoftwareSerial and the Particle Docs are talking about using Serial1 or Serial 2. Is it possible to still maintain a connection through USB whilst sending/reading to/from the RFID shield?

The original code from SF I need to sort out to fit Particle and use Cloud Functions (Publish, Subscribe)

#include <SoftwareSerial.h> //Used for transmitting to the device

SoftwareSerial softSerial(2, 3); //RX, TX

#include "SparkFun_UHF_RFID_Reader.h" //Library for controlling the M6E Nano module
RFID nano; //Create instance

#define BUZZER1 9
//#define BUZZER1 0 //For testing quietly
#define BUZZER2 10

void setup()
{
  Serial.begin(115200);

  pinMode(BUZZER1, OUTPUT);
  pinMode(BUZZER2, OUTPUT);

  digitalWrite(BUZZER2, LOW); //Pull half the buzzer to ground and drive the other half.

  while (!Serial);
  Serial.println();
  Serial.println("Initializing...");

  if (setupNano(38400) == false) //Configure nano to run at 38400bps
  {
    Serial.println("Module failed to respond. Please check wiring.");
    while (1); //Freeze!
  }

  nano.setRegion(REGION_NORTHAMERICA); //Set to North America

  nano.setReadPower(500); //5.00 dBm. Higher values may cause USB port to brown out
  //Max Read TX Power is 27.00 dBm and may cause temperature-limit throttling
}

void loop()
{
  Serial.println(F("Press a key to scan for a tag"));
  while (!Serial.available()); //Wait for user to send a character
  Serial.read(); //Throw away the user's character

  byte myEPC[12]; //Most EPCs are 12 bytes
  byte myEPClength;
  byte responseType = 0;

  while (responseType != RESPONSE_SUCCESS)//RESPONSE_IS_TAGFOUND)
  {
    myEPClength = sizeof(myEPC); //Length of EPC is modified each time .readTagEPC is called

    responseType = nano.readTagEPC(myEPC, myEPClength, 500); //Scan for a new tag up to 500ms
    Serial.println(F("Searching for tag"));
  }

  //Beep! Piano keys to frequencies: http://www.sengpielaudio.com/KeyboardAndFrequencies.gif
  tone(BUZZER1, 2093, 150); //C
  delay(150);
  tone(BUZZER1, 2349, 150); //D
  delay(150);
  tone(BUZZER1, 2637, 150); //E
  delay(150);

  //Print EPC
  Serial.print(F(" epc["));
  for (byte x = 0 ; x < myEPClength ; x++)
  {
    if (myEPC[x] < 0x10) Serial.print(F("0"));
    Serial.print(myEPC[x], HEX);
    Serial.print(F(" "));
  }
  Serial.println(F("]"));
}

//Gracefully handles a reader that is already configured and already reading continuously
//Because Stream does not have a .begin() we have to do this outside the library
boolean setupNano(long baudRate)
{
  nano.begin(softSerial); //Tell the library to communicate over software serial port

  //Test to see if we are already connected to a module
  //This would be the case if the Arduino has been reprogrammed and the module has stayed powered
  softSerial.begin(baudRate); //For this test, assume module is already at our desired baud rate
  while(!softSerial); //Wait for port to open

  //About 200ms from power on the module will send its firmware version at 115200. We need to ignore this.
  while(softSerial.available()) softSerial.read();
  
  nano.getVersion();

  if (nano.msg[0] == ERROR_WRONG_OPCODE_RESPONSE)
  {
    //This happens if the baud rate is correct but the module is doing a ccontinuous read
    nano.stopReading();

    Serial.println(F("Module continuously reading. Asking it to stop..."));

    delay(1500);
  }
  else
  {
    //The module did not respond so assume it's just been powered on and communicating at 115200bps
    softSerial.begin(115200); //Start software serial at 115200

    nano.setBaud(baudRate); //Tell the module to go to the chosen baud rate. Ignore the response msg

    softSerial.begin(baudRate); //Start the software serial port, this time at user's chosen baud rate
  }

  //Test the connection
  nano.getVersion();
  if (nano.msg[0] != ALL_GOOD) return (false); //Something is not right

  //The M6E has these settings no matter what
  nano.setTagProtocol(); //Set protocol to GEN2

  nano.setAntennaPort(); //Set TX/RX antenna ports to 1

  return (true); //We are ready to rock
}

The CPP file for Particle IDE

#include "UHF_RFID_Reader.h"

RFID::RFID(void){
    // Constructor
}

//Initialize the Serial port
bool RFID::begin(Stream &serialPort)
{
  _nanoSerial = &serialPort; //Grab which port the user wants us to use

  //_nanoSerial->begin(); //Stream has no .begin() so the user has to do a whateverSerial.begin(xxxx); from setup()
}

//Enable or disable the printing of sent/response HEX values.
//Use this in conjunction with 'Transport Logging' from the Universal Reader Assistant to see what they're doing that we're not
void RFID::enableDebugging(Stream &debugPort)
{
  _debugSerial = &debugPort; //Grab which port the user wants us to use for debugging
  
  _printDebug = true; //Should we print the commands we send? Good for debugging
}
void RFID::disableDebugging(void)
{
  _printDebug = false; //Turn off extra print statements
}

//Set baud rate
//Takes in a baud rate
//Returns response in the msg array
void RFID::setBaud(long baudRate)
{
  //Copy this setting into a temp data array
  uint8_t size = sizeof(baudRate);
  uint8_t data[size];
  for (uint8_t x = 0 ; x < size ; x++)
    data[x] = (uint8_t)(baudRate >> (8 * (size - 1 - x)));

  sendMessage(TMR_SR_OPCODE_SET_BAUD_RATE, data, size, COMMAND_TIME_OUT, false);
}

//Begin scanning for tags
//There are many many options and features to the nano, this sets options
//for continuous read of GEN2 type tags
void RFID::startReading()
{
  disableReadFilter(); //Don't filter for a specific tag, read all tags

  //This blob was found by using the 'Transport Logs' option from the Universal Reader Assistant
  //And connecting the Nano eval kit from Thing Magic to the URA
  //A lot of it has been deciphered but it's easier and faster just to pass a blob than to
  //assemble every option and sub-opcode.
  uint8_t configBlob[] = {0x00, 0x00, 0x01, 0x22, 0x00, 0x00, 0x05, 0x07, 0x22, 0x10, 0x00, 0x1B, 0x03, 0xE8, 0x01, 0xFF};

  /*
    //Timeout should be zero for true continuous reading
    SETU16(newMsg, i, 0);
    SETU8(newMsg, i, (uint8_t)0x1); // TM Option 1, for continuous reading
    SETU8(newMsg, i, (uint8_t)TMR_SR_OPCODE_READ_TAG_ID_MULTIPLE); // sub command opcode
    SETU16(newMsg, i, (uint16_t)0x0000); // search flags, only 0x0001 is supported
    SETU8(newMsg, i, (uint8_t)TMR_TAG_PROTOCOL_GEN2); // protocol ID
  */

  sendMessage(TMR_SR_OPCODE_MULTI_PROTOCOL_TAG_OP, configBlob, sizeof(configBlob));
}

//Stop a continuous read
void RFID::stopReading()
{
  //00 00 = Timeout, currently ignored
  //02 = Option - stop continuous reading
  uint8_t configBlob[] = {0x00, 0x00, 0x02};

  sendMessage(TMR_SR_OPCODE_MULTI_PROTOCOL_TAG_OP, configBlob, sizeof(configBlob), false); //Do not wait for response
}

void RFID::setRegion(uint8_t region)
{
  sendMessage(TMR_SR_OPCODE_SET_REGION, &region, sizeof(region));
}

//Sets the TX and RX antenna ports to 01
//Because the Nano module has only one antenna port, it is not user configurable
void RFID::setAntennaPort(void)
{
  uint8_t configBlob[] = {0x01, 0x01}; //TX port = 1, RX port = 1
  sendMessage(TMR_SR_OPCODE_SET_ANTENNA_PORT, configBlob, sizeof(configBlob));
}

//This was found in the logs. It seems to be very close to setAntennaPort
//Search serial_reader_l3.c for cmdSetAntennaSearchList for more info
void RFID::setAntennaSearchList(void)
{
  uint8_t configBlob[] = {0x02, 0x01, 0x01}; //logical antenna list option, TX port = 1, RX port = 1
  sendMessage(TMR_SR_OPCODE_SET_ANTENNA_PORT, configBlob, sizeof(configBlob));
}

void RFID::setTagProtocol(uint8_t protocol)
{
  uint8_t data[2];
  data[0] = 0; //Opcode expects 16-bits
  data[1] = protocol;

  sendMessage(TMR_SR_OPCODE_SET_TAG_PROTOCOL, data, sizeof(data));
}

void RFID::enableReadFilter(void)
{
  setReaderConfiguration(0x0C, 0x01); //Enable read filter
}

void RFID::disableReadFilter(void)
{
  setReaderConfiguration(0x0C, 0x00); //Diable read filter
}

void RFID::setReaderConfiguration(uint8_t option1, uint8_t option2)
{
  uint8_t data[3];

  //These are parameters gleaned from inspecting the 'Transport Logs' of the Universal Reader Assistant
  //And from serial_reader_l3.c
  data[0] = 1; //Key value form of command
  data[1] = option1;
  data[2] = option2;

  sendMessage(TMR_SR_OPCODE_SET_READER_OPTIONAL_PARAMS, data, sizeof(data));
}

void RFID::getOptionalParameters(uint8_t option1, uint8_t option2)
{
  //These are parameters gleaned from inspecting the 'Transport Logs' of the Universal Reader Assistant
  //During setup the software pings different options
  uint8_t data[2];
  data[0] = option1;
  data[1] = option2;
  sendMessage(TMR_SR_OPCODE_GET_READER_OPTIONAL_PARAMS, data, sizeof(data));
}

void RFID::getVersion(void)
{
  sendMessage(TMR_SR_OPCODE_VERSION);
}

void RFID::setReadPower(int16_t powerSetting)
{
  if (powerSetting > 2700) powerSetting = 2700; //Limit to 27dBm

  //Copy this setting into a temp data array
  uint8_t size = sizeof(powerSetting);
  uint8_t data[size];
  for (uint8_t x = 0 ; x < size ; x++)
    data[x] = (uint8_t)(powerSetting >> (8 * (size - 1 - x)));

  sendMessage(TMR_SR_OPCODE_SET_READ_TX_POWER, data, size);
}

void RFID::getReadPower()
{
  uint8_t data[] = {0x00}; //Just return power
  //uint8_t data[] = {0x01}; //Return power with limits

  sendMessage(TMR_SR_OPCODE_GET_READ_TX_POWER, data, sizeof(data));
}

void RFID::setWritePower(int16_t powerSetting)
{
  uint8_t size = sizeof(powerSetting);
  uint8_t data[size];
  for (uint8_t x = 0 ; x < size ; x++)
    data[x] = (uint8_t)(powerSetting >> (8 * (size - 1 - x)));

  sendMessage(TMR_SR_OPCODE_SET_WRITE_TX_POWER, data, size);
}

void RFID::getWritePower()
{
  uint8_t data[] = {0x00}; //Just return power
  //uint8_t data[] = {0x01}; //Return power with limits

  sendMessage(TMR_SR_OPCODE_GET_WRITE_TX_POWER, data, sizeof(data));
}

uint8_t RFID::readTagEPC(uint8_t *epc, uint8_t &epcLength, uint16_t timeOut)
{
  uint8_t bank = 0x01; //User data bank
  uint8_t address = 0x02; //Starts at 2

  return (readData(bank, address, epc, epcLength, timeOut));
}

// Get Compile error here - changed from Char to uint8_t
uint8_t RFID::writeTagEPC(uint8_t *newID, uint8_t newIDLength, uint16_t timeOut)
{
  uint8_t bank = 0x01; //EPC memory
  uint8_t address = 0x02; //EPC starts at spot 4

  return (writeData(bank, address, newID, newIDLength, timeOut));
}

uint8_t RFID::readUserData(uint8_t *userData, uint8_t &userDataLength, uint16_t timeOut)
{
  uint8_t bank = 0x03; //User data bank
  uint8_t address = 0x00; //Starts at 0

  return (readData(bank, address, userData, userDataLength, timeOut));
}

uint8_t RFID::writeUserData(uint8_t *userData, uint8_t userDataLength, uint16_t timeOut)
{
  uint8_t bank = 0x03; //User memory
  uint8_t address = 0x00;

  return (writeData(bank, address, userData, userDataLength, timeOut));
}
uint8_t RFID::writeKillPW(uint8_t *password, uint8_t passwordLength, uint16_t timeOut)
{
  uint8_t bank = 0x00; //Passwords bank
  uint8_t address = 0x00; //Kill password address

  return (writeData(bank, address, password, passwordLength, timeOut));
}
uint8_t RFID::readKillPW(uint8_t *password, uint8_t &passwordLength, uint16_t timeOut)
{
  uint8_t bank = 0x00; //Passwords bank
  uint8_t address = 0x00; //Kill password address

  return (readData(bank, address, password, passwordLength, timeOut));
}
uint8_t RFID::writeAccessPW(uint8_t *password, uint8_t passwordLength, uint16_t timeOut)
{
  uint8_t bank = 0x00; //Passwords bank
  uint8_t address = 0x02; //Access password address

  return (writeData(bank, address, password, passwordLength, timeOut));
}
uint8_t RFID::readAccessPW(uint8_t *password, uint8_t &passwordLength, uint16_t timeOut)
{
  uint8_t bank = 0x00; //Passwords bank
  uint8_t address = 0x02; //Access password address

  return (readData(bank, address, password, passwordLength, timeOut));
}
uint8_t RFID::readTID(uint8_t *tid, uint8_t &tidLength, uint16_t timeOut)
{
  uint8_t bank = 0x02; //Bank for TID
  uint8_t address = 0x02;

  return (readData(bank, address, tid, tidLength, timeOut));
}
uint8_t RFID::readUID(uint8_t *tid, uint8_t &tidLength, uint16_t timeOut)
{
  uint8_t bank = 0x02; //Bank for TID
  uint8_t address = 0x02; //UID of the TID starts at 4

  return (readData(bank, address, tid, tidLength, timeOut));
}
uint8_t RFID::writeData(uint8_t bank, uint32_t address, uint8_t *dataToRecord, uint8_t dataLengthToRecord, uint16_t timeOut)
{
  //Example: FF  0A  24  03  E8  00  00  00  00  00  03  00  EE  58  9D
  //FF 0A 24 = Header, LEN, Opcode
  //03 E8 = Timeout in ms
  //00 = Option initialize
  //00 00 00 00 = Address
  //03 = Bank
  //00 EE = Data
  //58 9D = CRC

  uint8_t data[8 + dataLengthToRecord];

  //Pre-load array options
  data[0] = timeOut >> 8 & 0xFF; //Timeout msB in ms
  data[1] = timeOut & 0xFF; //Timeout lsB in ms
  data[2] = 0x00; //Option initialize

  //Splice address into array
  for (uint8_t x = 0 ; x < sizeof(address) ; x++)
    data[3 + x] = address >> (8 * (3 - x)) & 0xFF;

  //Bank 0 = Passwords
  //Bank 1 = EPC Memory Bank
  //Bank 2 = TID
  //Bank 3 = User Memory
  data[7] = bank;

  //Splice data into array
  for (uint8_t x = 0 ; x < dataLengthToRecord ; x++)
    data[8 + x] = dataToRecord[x];

  sendMessage(TMR_SR_OPCODE_WRITE_TAG_DATA, data, sizeof(data), timeOut);

  if (msg[0] == ALL_GOOD) //We received a good response
  {
    uint16_t status = (msg[3] << 8) | msg[4];

    if (status == 0x0000)
      return (RESPONSE_SUCCESS);
  }

  //Else - msg[0] was timeout or other
  return (RESPONSE_FAIL);
}
uint8_t RFID::readData(uint8_t bank, uint32_t address, uint8_t *dataRead, uint8_t &dataLengthRead, uint16_t timeOut)
{
  //Bank 0
  //response: [00] [08] [28] [00] [00] [EE] [FF] [11] [22] [12] [34] [56] [78]
  //[EE] [FF] [11] [22] = Kill pw
  //[12] [34] [56] [78] = Access pw

  //Bank 1
  //response: [00] [08] [28] [00] [00] [28] [F0] [14] [00] [AA] [BB] [CC] [DD]
  //[28] [F0] = CRC
  //[14] [00] = PC
  //[AA] [BB] [CC] [DD] = EPC

  //Bank 2
  //response: [00] [18] [28] [00] [00] [E2] [00] [34] [12] [01] [6E] [FE] [00] [03] [7D] [9A] [A3] [28] [05] [01] [6B] [00] [05] [5F] [FB] [FF] [FF] [DC] [00]
  //[E2] = CIsID
  //[00] [34] [12] = Vendor ID = 003, Model ID == 412
  //[01] [6E] [FE] [00] [03] [7D] [9A] [A3] [28] [05] [01] [69] [10] [05] [5F] [FB] [FF] [FF] [DC] [00] = Unique ID (TID)

  //Bank 3
  //response: [00] [40] [28] [00] [00] [41] [43] [42] [44] [45] [46] [00] [00] [00] [00] [00] [00] ...
  //User data

  uint8_t data[8];

  //Insert timeout
  data[0] = timeOut >> 8 & 0xFF; //Timeout msB in ms
  data[1] = timeOut & 0xFF; //Timeout lsB in ms

  data[2] = bank; //Bank

  //Splice address into array
  for (uint8_t x = 0 ; x < sizeof(address) ; x++)
    data[3 + x] = address >> (8 * (3 - x)) & 0xFF;

  data[7] = dataLengthRead / 2; //Number of 16-bit chunks to read. 
  //0x00 will read the entire bank but may be more than we expect (both Kill and Access PW will be returned when reading bank 1 from address 0)
  
  //When reading the user data area we need to read the entire bank
  if(bank == 0x03) data[7] = 0x00;

  sendMessage(TMR_SR_OPCODE_READ_TAG_DATA, data, sizeof(data), timeOut);

  if (msg[0] == ALL_GOOD) //We received a good response
  {
    uint16_t status = (msg[3] << 8) | msg[4];

    if (status == 0x0000)
    {
      uint8_t responseLength = msg[1];

      if (responseLength < dataLengthRead) //User wants us to read more than we have available
        dataLengthRead = responseLength;

	  //There is a case here where responseLegnth is more than dataLengthRead, in which case we ignore (don't load) the additional bytes
      //Load limited response data into caller's array
	  for (uint8_t x = 0 ; x < dataLengthRead ; x++)
        dataRead[x] = msg[5 + x];
	  
      return (RESPONSE_SUCCESS);
    }
  }


  //Else - msg[0] was timeout or other
  dataLengthRead = 0; //Inform caller that we weren't able to read anything

  return (RESPONSE_FAIL);
}
uint8_t RFID::killTag(uint8_t *password, uint8_t passwordLength, uint16_t timeOut)
{
  uint8_t data[4 + passwordLength];

  data[0] = timeOut >> 8 & 0xFF; //Timeout msB in ms
  data[1] = timeOut & 0xFF; //Timeout lsB in ms
  data[2] = 0x00; //Option initialize

  //Splice password into array
  for (uint8_t x = 0 ; x < passwordLength ; x++)
    data[3 + x] = password[x];

  data[3 + passwordLength] = 0x00; //RFU

  sendMessage(TMR_SR_OPCODE_KILL_TAG, data, sizeof(data), timeOut);

  if (msg[0] == ALL_GOOD) //We received a good response
  {
    uint16_t status = (msg[3] << 8) | msg[4];

    if (status == 0x0000)
      return (RESPONSE_SUCCESS);
  }

  //Else - msg[0] was timeout or other
  return (RESPONSE_FAIL);
}
bool RFID::check()
{
  while (_nanoSerial->available())
  {
    uint8_t incomingData = _nanoSerial->read();

    //Wait for header byte
    if (_head == 0 && incomingData != 0xFF)
    {
      //Do nothing. Ignore this byte because we need a start byte
    }
    else
    {
      //Load this value into the array
      msg[_head++] = incomingData;

      _head %= MAX_MSG_SIZE; //Wrap variable

      if ((_head > 0) && (_head == msg[1] + 7))
      {
        //We've got a complete sentence!

        //Erase the remainder of the array
        for (uint8_t x = _head ; x < MAX_MSG_SIZE ; x++)
          msg[x] = 0;

        _head = 0; //Reset
		
		//Used for debugging: Does the user want us to print the command to serial port?
		if (_printDebug == true)
		{
		  _debugSerial->print(F("response: "));
		  printMessageArray();
		}

        return (true);
      }
	  
    }
  }

  return (false);
}

//See parseResponse for breakdown of fields
//Pulls the number of EPC bytes out of the response
//Often this is 12 bytes
uint8_t RFID::getTagEPCBytes(void)
{
  uint16_t epcBits = 0; //Number of bits of EPC (including PC, EPC, and EPC CRC)

  uint8_t tagDataBytes = getTagDataBytes(); //We need this offset

  for (uint8_t x = 0 ; x < 2 ; x++)
    epcBits |= (uint16_t)msg[27 + tagDataBytes + x] << (8 * (1 - x));
  uint8_t epcBytes = epcBits / 8;
  epcBytes -= 4; //Ignore the first two bytes and last two bytes

  return (epcBytes);
}

//See parseResponse for breakdown of fields
//Pulls the number of data bytes out of the response
//Often this is zero
uint8_t RFID::getTagDataBytes(void)
{
  //Number of bits of embedded tag data
  uint8_t tagDataLength = 0;
  for (uint8_t x = 0 ; x < 2 ; x++)
    tagDataLength |= (uint16_t)msg[24 + x] << (8 * (1 - x));
  uint8_t tagDataBytes = tagDataLength / 8;
  if (tagDataLength % 8 > 0) tagDataBytes++; //Ceiling trick

  return (tagDataBytes);
}

//See parseResponse for breakdown of fields
//Pulls the timestamp since last Keep-Alive message from a full response record stored in msg
uint16_t RFID::getTagTimestamp(void)
{
  //Timestamp since last Keep-Alive message
  uint32_t timeStamp = 0;
  for (uint8_t x = 0 ; x < 4 ; x++)
    timeStamp |= (uint32_t)msg[17 + x] << (8 * (3 - x));

  return (timeStamp);
}

//See parseResponse for breakdown of fields
//Pulls the frequency value from a full response record stored in msg
uint32_t RFID::getTagFreq(void)
{
  //Frequency of the tag detected is loaded over three bytes
  uint32_t freq = 0;
  for (uint8_t x = 0 ; x < 3 ; x++)
    freq |= (uint32_t)msg[14 + x] << (8 * (2 - x));

  return (freq);
}

//See parseResponse for breakdown of fields
//Pulls the RSSI value from a full response record stored in msg
int8_t RFID::getTagRSSI(void)
{
  return (msg[12] - 256);
}

//This will parse whatever response is currently in msg into its constituents
//Mostly used for parsing out the tag IDs and RSSI from a multi tag continuous read
uint8_t RFID::parseResponse(void)
{
  //See http://www.thingmagic.com/images/Downloads/Docs/AutoConfigTool_1.2-UserGuide_v02RevA.pdf
  //for a breakdown of the response packet

  //Example response:
  //FF  28  22  00  00  10  00  1B  01  FF  01  01  C4  11  0E  16
  //40  00  00  01  27  00  00  05  00  00  0F  00  80  30  00  00
  //00  00  00  00  00  00  00  00  00  15  45  E9  4A  56  1D
  //  [0] FF = Header
  //  [1] 28 = Message length
  //  [2] 22 = OpCode
  //  [3, 4] 00 00 = Status
  //  [5 to 11] 10 00 1B 01 FF 01 01 = RFU 7 bytes
  //  [12] C4 = RSSI
  //  [13] 11 = Antenna ID (4MSB = TX, 4LSB = RX)
  //  [14, 15, 16] 0E 16 40 = Frequency in kHz
  //  [17, 18, 19, 20] 00 00 01 27 = Timestamp in ms since last keep alive msg
  //  [21, 22] 00 00 = phase of signal tag was read at (0 to 180)
  //  [23] 05 = Protocol ID
  //  [24, 25] 00 00 = Number of bits of embedded tag data [M bytes]
  //  [26 to M] (none) = Any embedded data
  //  [26 + M] 0F = RFU reserved future use
  //  [27, 28 + M] 00 80 = EPC Length [N bytes]  (bits in EPC including PC and CRC bits). 128 bits = 16 bytes
  //  [29, 30 + M] 30 00 = Tag EPC Protocol Control (PC) bits
  //  [31 to 42 + M + N] 00 00 00 00 00 00 00 00 00 00 15 45 = EPC ID
  //  [43, 44 + M + N] 45 E9 = EPC CRC
  //  [45, 46 + M + N] 56 1D = Message CRC

  uint8_t msgLength = msg[1] + 7; //Add 7 (the header, length, opcode, status, and CRC) to the LEN field to get total bytes
  uint8_t opCode = msg[2];

  //Check the CRC on this response
  uint16_t messageCRC = calculateCRC(&msg[1], msgLength - 3 ); //Ignore header (start spot 1), remove 3 bytes (header + 2 CRC)
  if ((msg[msgLength - 2] != (messageCRC >> 8)) || (msg[msgLength - 1] != (messageCRC & 0xFF)))
  {
    return (ERROR_CORRUPT_RESPONSE);
  }

  if (opCode == TMR_SR_OPCODE_READ_TAG_ID_MULTIPLE) //opCode = 0x22
  {
    //Based on the record length identify if this is a tag record, a temperature sensor record, or a keep-alive?
    if (msg[1] == 0x00) //Keep alive
    {
      //We have a Read cycle reset/keep-alive message
      //Sent once per second
      uint16_t statusMsg = 0;
      for (uint8_t x = 0 ; x < 2 ; x++)
        statusMsg |= (uint32_t)msg[3 + x] << (8 * (1 - x));

      if (statusMsg == 0x0400)
      {
        return (RESPONSE_IS_KEEPALIVE);
      }
      else if (statusMsg == 0x0504)
      {
        return (RESPONSE_IS_TEMPTHROTTLE);
      }
    }
    else if (msg[1] == 0x08) //Unknown
    {
      return (RESPONSE_IS_UNKNOWN);
    }
    else if (msg[1] == 0x0a) //temperature
    {
        return (RESPONSE_IS_TEMPERATURE);
    }
    else //Full tag record
    {
      //This is a full tag response
      //User can now pull out RSSI, frequency of tag, timestamp, EPC, Protocol control bits, EPC CRC, CRC
      return (RESPONSE_IS_TAGFOUND);
    }
  }
  else
  {
    if (_printDebug == true)
	{
		_debugSerial->print(F("Unknown opcode in response: 0x"));
		_debugSerial->println(opCode, HEX);
	}
    return (ERROR_UNKNOWN_OPCODE);
  }

}

//Given an opcode, a piece of data, and the size of that data, package up a sentence and send it
void RFID::sendMessage(uint8_t opcode, uint8_t *data, uint8_t size, uint16_t timeOut, boolean waitForResponse)
{
  msg[1] = size; //Load the length of this operation into msg array
  msg[2] = opcode;

  //Copy the data into msg array
  for (uint8_t x = 0 ; x < size ; x++)
    msg[3 + x] = data[x];

  sendCommand(timeOut, waitForResponse); //Send and wait for response
}

//Given an array, calc CRC, assign header, send it out
//Modifies the caller's msg array
void RFID::sendCommand(uint16_t timeOut, boolean waitForResponse)
{
  msg[0] = 0xFF; //Universal header
  uint8_t messageLength = msg[1];

  uint8_t opcode = msg[2]; //Used to see if response from module has the same opcode

  //Attach CRC
  uint16_t crc = calculateCRC(&msg[1], messageLength + 2); //Calc CRC starting from spot 1, not 0. Add 2 for LEN and OPCODE bytes.
  msg[messageLength + 3] = crc >> 8;
  msg[messageLength + 4] = crc & 0xFF;

  //Used for debugging: Does the user want us to print the command to serial port?
  if (_printDebug == true)
  {
    _debugSerial->print(F("sendCommand: "));
    printMessageArray();
  }

  //Remove anything in the incoming buffer
  //TODO this is a bad idea if we are constantly readings tags
  while (_nanoSerial->available()) _nanoSerial->read();

  //Send the command to the module
  for (uint8_t x = 0 ; x < messageLength + 5 ; x++)
    _nanoSerial->write(msg[x]);

  //There are some commands (setBaud) that we can't or don't want the response
  if (waitForResponse == false)
  {
	_nanoSerial->flush(); //Wait for serial sending to complete
	return;
  }

  //For debugging, probably remove
  //for (uint8_t x = 0 ; x < 100 ; x++) msg[x] = 0;

  //Wait for response with timeout
  uint32_t startTime = millis();
  while (_nanoSerial->available() == false)
  {
    if (millis() - startTime > timeOut)
    {
      if (_printDebug == true) _debugSerial->println(F("Time out 1: No response from module"));
      msg[0] = ERROR_COMMAND_RESPONSE_TIMEOUT;
      return;
    }
    delay(1);
  }

  // Layout of response in data array:
  // [0] [1] [2] [3]      [4]      [5] [6]  ... [LEN+4] [LEN+5] [LEN+6]
  // FF  LEN OP  STATUSHI STATUSLO xx  xx   ... xx      CRCHI   CRCLO
  messageLength = MAX_MSG_SIZE - 1; //Make the max length for now, adjust it when the actual len comes in
  uint8_t spot = 0;
  while (spot < messageLength)
  {
    if (millis() - startTime > timeOut)
    {
      if (_printDebug == true) _debugSerial->println(F("Time out 2: Incomplete response"));

      msg[0] = ERROR_COMMAND_RESPONSE_TIMEOUT;
      return;
    }

    if (_nanoSerial->available())
    {
      msg[spot] = _nanoSerial->read();

      if (spot == 1) //Grab the length of this response (spot 1)
        messageLength = msg[1] + 7; //Actual length of response is ? + 7 for extra stuff (header, Length, opcode, 2 status bytes, ..., 2 bytes CRC = 7)

      spot++;

      //There's a case were we miss the end of one message and spill into another message.
      //We don't want spot pointing at an illegal spot in the array
      spot %= MAX_MSG_SIZE; //Wrap condition
    }
  }

  //Used for debugging: Does the user want us to print the command to serial port?
  if (_printDebug == true)
  {
    _debugSerial->print(F("response: "));
    printMessageArray();
  }

  //Check CRC
  crc = calculateCRC(&msg[1], messageLength - 3); //Remove header, remove 2 crc bytes
  if ((msg[messageLength - 2] != (crc >> 8)) || (msg[messageLength - 1] != (crc & 0xFF)))
  {
    msg[0] = ERROR_CORRUPT_RESPONSE;
    if (_printDebug == true) _debugSerial->println(F("Corrupt response"));
    return;
  }

  //If crc is ok, check that opcode matches (did we get a response to the command we sent or a different one?)
  if (msg[2] != opcode)
  {
    msg[0] = ERROR_WRONG_OPCODE_RESPONSE;
    if (_printDebug == true) _debugSerial->println(F("Wrong opcode response"));
    return;
  }

  //If everything is ok, load all ok into msg array
  msg[0] = ALL_GOOD;

}

//Print the current message array - good for debugging, looking at how the module responded
//TODO Don't hardcode the serial stream
void RFID::printMessageArray(void)
{
  if(_printDebug == true) //If user hasn't enabled debug we don't know what port to debug to
  {
	uint8_t amtToPrint = msg[1] + 5;
	if (amtToPrint > MAX_MSG_SIZE) amtToPrint = MAX_MSG_SIZE; //Limit this size
	  
	for (uint16_t x = 0 ; x < amtToPrint ; x++)
	{
	  _debugSerial->print(" [");
	  if (msg[x] < 0x10) _debugSerial->print("0");
	  _debugSerial->print(msg[x], HEX);
	  _debugSerial->print("]");
	}
	_debugSerial->println();
  }
}

//Comes from serial_reader_l3.c
//ThingMagic-mutated CRC used for messages.
//Notably, not a CCITT CRC-16, though it looks close.
static uint16_t crctable[] =
{
  0x0000, 0x1021, 0x2042, 0x3063,
  0x4084, 0x50a5, 0x60c6, 0x70e7,
  0x8108, 0x9129, 0xa14a, 0xb16b,
  0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
};

//Calculates the magical CRC value
uint16_t RFID::calculateCRC(uint8_t *u8Buf, uint8_t len)
{
  uint16_t crc = 0xFFFF;

  for (uint8_t i = 0 ; i < len ; i++)
  {
    crc = ((crc << 4) | (u8Buf[i] >> 4)) ^ crctable[crc >> 12];
    crc = ((crc << 4) | (u8Buf[i] & 0x0F)) ^ crctable[crc >> 12];
  }

  return crc;
}

and the H file fitted to the Particle IDE

#include "Particle.h"

#define MAX_MSG_SIZE 255
#define TMR_SR_OPCODE_VERSION 0x03
#define TMR_SR_OPCODE_SET_BAUD_RATE 0x06
#define TMR_SR_OPCODE_READ_TAG_ID_SINGLE 0x21
#define TMR_SR_OPCODE_READ_TAG_ID_MULTIPLE 0x22
#define TMR_SR_OPCODE_WRITE_TAG_ID 0x23
#define TMR_SR_OPCODE_WRITE_TAG_DATA 0x24
#define TMR_SR_OPCODE_KILL_TAG 0x26
#define TMR_SR_OPCODE_READ_TAG_DATA 0x28
#define TMR_SR_OPCODE_CLEAR_TAG_ID_BUFFER 0x2A
#define TMR_SR_OPCODE_MULTI_PROTOCOL_TAG_OP 0x2F
#define TMR_SR_OPCODE_GET_READ_TX_POWER 0x62
#define TMR_SR_OPCODE_GET_WRITE_TX_POWER 0x64
#define TMR_SR_OPCODE_GET_POWER_MODE 0x68
#define TMR_SR_OPCODE_GET_READER_OPTIONAL_PARAMS 0x6A
#define TMR_SR_OPCODE_GET_PROTOCOL_PARAM 0x6B
#define TMR_SR_OPCODE_SET_ANTENNA_PORT 0x91
#define TMR_SR_OPCODE_SET_TAG_PROTOCOL 0x93
#define TMR_SR_OPCODE_SET_READ_TX_POWER 0x92
#define TMR_SR_OPCODE_SET_WRITE_TX_POWER 0x94
#define TMR_SR_OPCODE_SET_REGION 0x97
#define TMR_SR_OPCODE_SET_READER_OPTIONAL_PARAMS 0x9A
#define TMR_SR_OPCODE_SET_PROTOCOL_PARAM 0x9B

#define COMMAND_TIME_OUT  2000 //Number of ms before stop waiting for response from module

//Define all the ways functions can return
#define ALL_GOOD                        0
#define ERROR_COMMAND_RESPONSE_TIMEOUT  1
#define ERROR_CORRUPT_RESPONSE          2
#define ERROR_WRONG_OPCODE_RESPONSE     3
#define ERROR_UNKNOWN_OPCODE            4
#define RESPONSE_IS_TEMPERATURE         5
#define RESPONSE_IS_KEEPALIVE           6
#define RESPONSE_IS_TEMPTHROTTLE        7
#define RESPONSE_IS_TAGFOUND            8
#define RESPONSE_IS_NOTAGFOUND          9
#define RESPONSE_IS_UNKNOWN             10
#define RESPONSE_SUCCESS  			    11
#define RESPONSE_FAIL          			12

//Define the allowed regions - these set the internal freq of the module
#define REGION_INDIA        0x04
#define REGION_JAPAN        0x05
#define REGION_CHINA        0x06
#define REGION_EUROPE       0x08
#define REGION_KOREA        0x09
#define REGION_AUSTRALIA    0x0B
#define REGION_NEWZEALAND   0x0C
#define REGION_NORTHAMERICA 0x0D
#define REGION_OPEN         0xFF

class RFID{
    public: 
        RFID(void);
        
        bool begin(Stream &serialPort = Serial); //If user doesn't specify then Serial will be used
        void enableDebugging(Stream &debugPort = Serial); //Turn on command sending and response printing. If user doesn't specify then Serial will be used
        void disableDebugging(void);
        
        void setBaud(long baudRate);
        void getVersion(void);
        void setReadPower(int16_t powerSetting);
        void getReadPower();
        void setWritePower(int16_t powerSetting);
        void getWritePower();
        void setRegion(uint8_t region);
        void setAntennaPort();
        void setAntennaSearchList();
        
        void setTagProtocol(uint8_t protocol = 0x05);
        
        void startReading(void); //Disable filtering and start reading continuously
        void stopReading(void); //Stops continuous read. Give 1000 to 2000ms for the module to stop reading.
        
        void enableReadFilter(void);
        void disableReadFilter(void);
        
        void setReaderConfiguration(uint8_t option1, uint8_t option2);
        void getOptionalParameters(uint8_t option1, uint8_t option2);
        void setProtocolParameters(void);
        void getProtocolParameters(uint8_t option1, uint8_t option2);
        
        uint8_t parseResponse(void);
        
        uint8_t getTagEPCBytes(void); //Pull number of EPC data bytes from record response.
        uint8_t getTagDataBytes(void); //Pull number of tag data bytes from record response. Often zero.
        uint16_t getTagTimestamp(void); //Pull timestamp value from full record response
        uint32_t getTagFreq(void); //Pull Freq value from full record response
        int8_t getTagRSSI(void); //Pull RSSI value from full record response
        
        bool check(void);

        uint8_t readTagEPC(uint8_t *epc, uint8_t &epcLength, uint16_t timeOut = COMMAND_TIME_OUT);
        
        // Get Compile error here - changed from Char to uint8_t
        uint8_t writeTagEPC(uint8_t *newID, uint8_t newIDLength, uint16_t timeOut = COMMAND_TIME_OUT);

        uint8_t readData(uint8_t bank, uint32_t address, uint8_t *dataRead, uint8_t &dataLengthRead, uint16_t timeOut = COMMAND_TIME_OUT);
	    uint8_t writeData(uint8_t bank, uint32_t address, uint8_t *dataToRecord, uint8_t dataLengthToRecord, uint16_t timeOut = COMMAND_TIME_OUT);

        uint8_t readUserData(uint8_t *userData, uint8_t &userDataLength, uint16_t timeOut = COMMAND_TIME_OUT);
        uint8_t writeUserData(uint8_t *userData, uint8_t userDataLength, uint16_t timeOut = COMMAND_TIME_OUT);

	    uint8_t readKillPW(uint8_t *password, uint8_t &passwordLength, uint16_t timeOut = COMMAND_TIME_OUT);
	    uint8_t writeKillPW(uint8_t *password, uint8_t passwordLength, uint16_t timeOut = COMMAND_TIME_OUT);

	    uint8_t readAccessPW(uint8_t *password, uint8_t &passwordLength, uint16_t timeOut = COMMAND_TIME_OUT);
	    uint8_t writeAccessPW(uint8_t *password, uint8_t passwordLength, uint16_t timeOut = COMMAND_TIME_OUT);

	    uint8_t readTID(uint8_t *tid, uint8_t &tidLength, uint16_t timeOut = COMMAND_TIME_OUT);
	    uint8_t readUID(uint8_t *tid, uint8_t &tidLength, uint16_t timeOut = COMMAND_TIME_OUT);

        uint8_t killTag(uint8_t *password, uint8_t passwordLength, uint16_t timeOut = COMMAND_TIME_OUT);

        void sendMessage(uint8_t opcode, uint8_t *data = 0, uint8_t size = 0, uint16_t timeOut = COMMAND_TIME_OUT, boolean waitForResponse = true);
        void sendCommand(uint16_t timeOut = COMMAND_TIME_OUT, boolean waitForResponse = true);

        void printMessageArray(void);

        uint16_t calculateCRC(uint8_t *u8Buf, uint8_t len);
        
        uint8_t msg[MAX_MSG_SIZE];

        //uint16_t tags[MAX_NUMBER_OF_TAGS][12]; //Assumes EPC won't be longer than 12 bytes
        //uint16_t tagRSSI[MAX_NUMBER_OF_TAGS];  
        //uint16_t uniqueTags = 0;
    
    private:
    
        Stream *_nanoSerial; //The generic connection to user's chosen serial hardware

        Stream *_debugSerial; //The stream to send debug messages to if enabled

        uint8_t _head = 0; //Tracks the length of the incoming message as we poll the software serial
    
        boolean _printDebug = false; //Flag to print the serial commands we are sending to the Serial port for debug
    
};

I thought I should also mention here that the Photon RedBoard does not like when you plug a LiPo in the spot provided on the RFID shield. It seems to make the RGB glow red then shut off.

So I edited the SF Example .ino for the Photon and compiled without error. The Photon accepts it and then shortly after reseting it goes into Cloud Not Connect Mode (SOLID GREEN RGB).

Code:

#include "UHF_RFID_Reader.h" //Library for controlling the M6E Nano module

RFID nano; //Create instance

// #define BUZZER1 9
// #define BUZZER2 10

void setup()
{
  Serial.begin(115200);

//   pinMode(BUZZER1, OUTPUT);
//   pinMode(BUZZER2, OUTPUT);

  //digitalWrite(BUZZER2, LOW); //Pull half the buzzer to ground and drive the other half.

  while (!Serial);
  Serial.println();
  Serial.println("Initializing...");

  if (setupNano(38400) == false) //Configure nano to run at 38400bps
  {
    Serial.println("Module failed to respond. Please check wiring.");
    while (1); //Freeze!
  }

  nano.setRegion(REGION_NORTHAMERICA); //Set to North America

  nano.setReadPower(500); //5.00 dBm. Higher values may cause USB port to brown out
  //Max Read TX Power is 27.00 dBm and may cause temperature-limit throttling
}

void loop()
{
  Serial.println(F("Press a key to scan for a tag"));
  while (!Serial.available()); //Wait for user to send a character
  Serial.read(); //Throw away the user's character

  byte myEPC[12]; //Most EPCs are 12 bytes
  byte myEPClength;
  byte responseType = 0;

  while (responseType != RESPONSE_SUCCESS)//RESPONSE_IS_TAGFOUND)
  {
    myEPClength = sizeof(myEPC); //Length of EPC is modified each time .readTagEPC is called

    responseType = nano.readTagEPC(myEPC, myEPClength, 500); //Scan for a new tag up to 500ms
    Serial.println(F("Searching for tag"));
  }

  //Beep! Piano keys to frequencies: http://www.sengpielaudio.com/KeyboardAndFrequencies.gif
//   tone(BUZZER1, 2093, 150); //C
//   delay(150);
//   tone(BUZZER1, 2349, 150); //D
//   delay(150);
//   tone(BUZZER1, 2637, 150); //E
//   delay(150);

  //Print EPC
  Serial.print(F(" epc["));
  for (byte x = 0 ; x < myEPClength ; x++)
  {
    if (myEPC[x] < 0x10) Serial.print(F("0"));
    Serial.print(myEPC[x], HEX);
    Serial.print(F(" "));
  }
  Serial.println(F("]"));
}

//Gracefully handles a reader that is already configured and already reading continuously
//Because Stream does not have a .begin() we have to do this outside the library
boolean setupNano(long baudRate)
{
  nano.begin(Serial1); //Tell the library to communicate over software serial port

  //Test to see if we are already connected to a module
  //This would be the case if the Arduino has been reprogrammed and the module has stayed powered
  Serial1.begin(baudRate); //For this test, assume module is already at our desired baud rate
  while(!Serial1); //Wait for port to open

  //About 200ms from power on the module will send its firmware version at 115200. We need to ignore this.
  while(Serial1.available()) Serial1.read();
  
  nano.getVersion();

  if (nano.msg[0] == ERROR_WRONG_OPCODE_RESPONSE)
  {
    //This happens if the baud rate is correct but the module is doing a ccontinuous read
    nano.stopReading();

    Serial.println(F("Module continuously reading. Asking it to stop..."));

    delay(1500);
  }
  else
  {
    //The module did not respond so assume it's just been powered on and communicating at 115200bps
    Serial1.begin(115200); //Start software serial at 115200

    nano.setBaud(baudRate); //Tell the module to go to the chosen baud rate. Ignore the response msg

    Serial1.begin(baudRate); //Start the software serial port, this time at user's chosen baud rate
  }

  //Test the connection
  nano.getVersion();
  if (nano.msg[0] != ALL_GOOD) return (false); //Something is not right

  //The M6E has these settings no matter what
  nano.setTagProtocol(); //Set protocol to GEN2

  nano.setAntennaPort(); //Set TX/RX antenna ports to 1

  return (true); //We are ready to rock
}

I would also like to acknowledge that mixing RF could cause for disaster but I will be using an external antenna for the RFID so hopefully this mitigates some (if not all of the potentials) of error this may cause.