Comments: Simultaneous RFID Tag Reader Hookup Guide


Comments 15 comments

  • When I run Example2_Read_EPC, following pop up:

    C:\Users\mchow\Documents\Arduino\libraries\SparkFun_Simultaneous_RFID_Tag_Reader_Library\src\SparkFun_UHF_RFID_Reader.cpp: In member function ‘uint8_t RFID::writeTagEPC(char*, uint8_t, uint16_t)’:

    C:\Users\mchow\Documents\Arduino\libraries\SparkFun_Simultaneous_RFID_Tag_Reader_Library\src\SparkFun_UHF_RFID_Reader.cpp:277:63: error: invalid conversion from ‘char’ to ‘uint8_t {aka unsigned char*}’ [-fpermissive]

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


    In file included from C:\Users\mchow\Documents\Arduino\libraries\SparkFun_Simultaneous_RFID_Tag_Reader_Library\src\SparkFun_UHF_RFID_Reader.cpp:42:0:

    C:\Users\mchow\Documents\Arduino\libraries\SparkFun_Simultaneous_RFID_Tag_Reader_Library\src\SparkFun_UHF_RFID_Reader.h:119:10: error: initializing argument 3 of ‘uint8_t RFID::writeData(uint8_t, uint32_t, uint8_t*, uint8_t, uint16_t)’ [-fpermissive]

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


    exit status 1 Error compiling for board Arduino/Genuino Uno.

    I had no idea what’s going wrong, the examples seem can’t compile

  • Hi guys, Can someone please share the wiring diagram for use it with Arduino Uno/Nano without using a RedBoard ?


  • Is the duty cycle of the reader implemented in this code? In Magic’s Universal Reader Assistant it allows for ontime and offtime for a read duty cycle. This is important if you read at high levels of DB, higher levels the chip starts to heat up, by having a duty cycle of off and on the temperature can be controlled. In the API code it has asyncOffTime and asyncOnTime to control that. But I don’t see that in the Arduino code.

    Any ideas on this?

  • Is there a way to power this via an external supply, i..e “Target Power” and still use the serial out of the Arduino to connect to Universal Reader Assistant? I cant seem to get the software to recognize the module while it’s attached to the arduino (through which I’m powering the module).

  • After attaching the RFID reader to my arduino uno, uploading the first example script “constant read” I receive an error message via the serial monitor: “Module failed to respond. Please check wiring.” Is there a fix for this? I cant seem to find anything anywhere resolving this issue, and there’s not much ‘wiring to fix’ as i simply followed the instructions in the hardware hookup guide, attached headers to the board and attached it to the arduino. When powered from serial communication only (5v) it works fine with the universal reader assistant. Any guidance or suggestions would be helpful. Thank you!

    • check wiri

      any fix for this? i get this error randomly and there is only one source on the entire internet that attempts to resolve it (, albeit to to avail. Obviously, if you dont have the switch set it respond in the first place. however, it appears that if the module browns out or loses power during a reset it locks up and you apparently only have 200ms from when the arduino powers up to when the module responds to deal with resetting it. or something… for how finicky this device is, it is a nightmare when it decides not to work…

    • Have you set the Serial switch to SW-UART when you try running the Arduino sketches?

      If the switch is not the problem then… If the serial connection to a USB-to-Serial board is working with URA, but the Arduino connection is not, then double check your solder connections on the Arduino headers. You may have a disconnect on pins 2 and 3 (the software serial pins). If that’s not the problem then you may need to contact tech support.

  • I just order this KIT, install newest version Arduino, library, chose UNO as target board. I run Example1_Constant Read and had the following pop up:

    C:\Users\mchow\AppData\Local\Temp\arduino_modified_sketch_627756\Example1_Constant_Read.ino: In function ‘void loop()’:

    Example1_Constant_Read:79: error: ‘tagDataBytes’ was not declared in this scope

         if (nano.msg[31 + tagDataBytes + x] < 0x10) Serial.print(F("0")); //Pretty print

    Example1_Constant_Read:80: error: ‘tagDataBytes’ was not declared in this scope

         Serial.print(nano.msg[31 + tagDataBytes + x], HEX);

    exit status 1 ‘tagDataBytes’ was not declared in this scope

    Can anyone help?

  • Hello sparkfun, first sorry for my bad english :/

    I’m working with this Reader, but I need a little help. is possible to use the Arduino library for the M6E-NANO RFID module with a different board? like Adafruit Feather family with ATmega32u4 or Arduino Leonardo. is there any concern about the SoftwareSerial library that I need take in consideration?



    • I don’t think there will be a problem. The easiest way to test is by having the platform send and receive serial characters at 115200 over software serial. If the platform is able to send and receive correctly it should work fine with the reader.

      • This board does not work with boards based on atmega32u4 (Leonardo, Yun, etc) or on the Megas. None of these support interrupts on pins 2/3, so SoftwareSerial won’t work on those pins. I just found this out the hard way =(

If you've found a bug or have other constructive feedback for our tutorial authors, please send us your feedback!