Published February 6, 2019

Simple NFC Reader

This project demonstrates reading an NFC tag and controlling the RGB LED with a PN1720 controller.

BeginnerShowcase (no instructions)4 hours1,159

Things used in this project

Hardware components

NXP NFC Reader - PN7120

NXP LPC824 Xpresso Board

NFC Coins

Story

This project demonstrates the controlling of an RGB LED by reading NFC tags via NFC reader (PN1720). LPC824 Xpresso board is interfaced with PN1720 controller via I2C Interface.

NFC coins are pre programmed with texts field "RED," "BLUE," "GREEN" and "WHITE."

The LPC824 Xpresso board comes with RGB LED, which is going to be controlled via NFG tags. PN1720 can operate in read or write mode for this demo by default its configured to read mode.

Flashing the NFC coins on the reader antenna (2cm maximum) will change the color of RGB based on the text which written on the Tag.

The working demo is here:

Code

NFCTasks

void NdefPull_Cb(unsigned char *pNdefMessage, unsigned short NdefMessageSize)
{
    unsigned char *pNdefRecord = pNdefMessage;
    unsigned char save;

    NdefRecord_t NdefRecord;

    if (pNdefMessage == NULL)
    {
        printf("--- Provisioned buffer size too small or NDEF message empty \n");
        return;
    }

    while (pNdefRecord != NULL)
    {
        printf("--- NDEF record received:\n");

        NdefRecord = DetectNdefRecordType(pNdefRecord);

        if(NdefRecord.recordType == WELL_KNOWN_SIMPLE_TEXT)
        {

                save = NdefRecord.recordPayload[NdefRecord.recordPayloadSize];
                NdefRecord.recordPayload[NdefRecord.recordPayloadSize] = '\0';
                printf("   Text record: %s\n", &NdefRecord.recordPayload[NdefRecord.recordPayload[0]+1]);

                memcpy(&read_message_buffer[0],&NdefRecord.recordPayload[NdefRecord.recordPayload[0]+1], NdefRecord.recordPayloadSize);
                NdefRecord.recordPayload[NdefRecord.recordPayloadSize] = save;

                switch(read_message_buffer[0]){

                case 'R':
                	Board_LED_Set(0, false);
                    Board_LED_Set(1, false);
                    Board_LED_Set(2, true);
                    break;
                case 'G':
                	Board_LED_Set(0, false);
                    Board_LED_Set(1, true);
                    Board_LED_Set(2, false);
                    break;
                case 'B':
                	Board_LED_Set(0, true);
                    Board_LED_Set(1, false);
                    Board_LED_Set(2, false);
                    break;
                case 'W':
                	Board_LED_Set(0, true);
                    Board_LED_Set(1, true);
                    Board_LED_Set(2, true);
                    break;
                }
            }
        else{
            printf("   Unsupported NDEF record, cannot parse\n");
        }
        pNdefRecord = GetNextRecord(pNdefRecord);
    }

    printf("\n");
}

Credits

Ashok R

37 projects • 102 followers

Hobbyist/Engineer/Director/Animatior

Simple NFC Reader

Things used in this project

Hardware components

Story

Schematics

Schematic

Code

NFCTasks

Credits

Ashok R

Comments

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Simple NFC Reader

Simple NFC Reader

Things used in this project

Hardware components

Story

Schematics

Schematic

Code

NFCTasks

Credits

Ashok R

Comments

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