nfc/source/main.c

#include <stdio.h>
#include <string.h>
 
#include <3ds.h>
 
Result nfc_test()
{
    Result ret=0;
    u32 pos;
    FILE *f;
    size_t tmpsize;
 
    NFC_TagState prevstate, curstate;
    NFC_TagInfo taginfo;
    NFC_AmiiboSettings amiibosettings;
    NFC_AmiiboConfig amiiboconfig;
 
    u32 amiibo_appid = 0x10110E00;//Hard-coded for Super Smash Bros. See also: https://www.3dbrew.org/wiki/Amiibo
    u32 appdata_initialized;
 
    u8 appdata[0xd8];
 
    char uidstr[16];
    char tmpstr[64];
 
    printf("NFC initialized successfully, starting scanning...\n");
 
    ret = nfcStartScanning(NFC_STARTSCAN_DEFAULTINPUT);
    if(R_FAILED(ret))
    {
        printf("nfcStartScanning() failed.\n");
        return ret;
    }
 
    ret = nfcGetTagState(&curstate);
    if(R_FAILED(ret))
    {
        printf("nfcGetTagState() failed.\n");
        nfcStopScanning();
        return ret;
    }
 
    prevstate = curstate;
 
    printf("Press B to stop scanning or Y to restart scanning.\n");
    printf("Press X after an amiibo was successfully\nprocessed while still in range, to reprocess it.\n");
    printf("Hold down A while processing an amiibo to write\nappdata from SD to it. The amiibo appdata will be\ninitialized if it wasn't initialized already.\n");
    printf("Scanning must be restarted after a NFC tag goes\nout-of-range, if you want to scan more tag(s).\n");
 
    while(1)
    {
        gspWaitForVBlank();
        hidScanInput();
 
        u32 kDown = hidKeysDown();
 
        if(kDown & KEY_B)break;
 
        if(kDown & KEY_Y)//If you want this to be done automatically, you could run this when the TagState changes to NFC_TagState_OutOfRange.
        {
            printf("Restarting scanning...\n");
 
            nfcStopScanning();
            ret = nfcStartScanning(NFC_STARTSCAN_DEFAULTINPUT);
            if(R_FAILED(ret))
            {
                printf("nfcStartScanning() failed.\n");
                return ret;
            }
 
            printf("Scanning restarted.\n");
 
            continue;
        }
 
        if(kDown & KEY_X)
        {
            ret = nfcResetTagScanState();
            if(R_FAILED(ret))
            {
                printf("nfcResetTagScanState() failed.\n");
                break;
            }
 
            printf("nfcResetTagScanState() was successful.\n");
        }
 
        ret = nfcGetTagState(&curstate);
        if(R_FAILED(ret))
        {
            printf("nfcGetTagState() failed.\n");
            break;
        }
 
        if(curstate!=prevstate)//See nfc.h for the TagState values.
        {
            printf("TagState changed from %d to %d.\n", prevstate, curstate);
            prevstate = curstate;
 
            if(curstate==NFC_TagState_InRange)
            {
                memset(&taginfo, 0, sizeof(NFC_TagInfo));
                memset(&amiibosettings, 0, sizeof(NFC_AmiiboSettings));
 
                ret = nfcGetTagInfo(&taginfo);
                if(R_FAILED(ret))
                {
                    printf("nfcGetTagInfo() failed.\n");
                    break;
                }
 
                printf("taginfo id_offset_size: 0x%x.\n", (unsigned int)taginfo.id_offset_size);
                printf("NFC tag UID:\n");
 
                memset(uidstr, 0, sizeof(uidstr));
                for(pos=0; pos<7; pos++)snprintf(&uidstr[pos*2], 3, "%02x", taginfo.id[pos]);
                printf("%s\n", uidstr);
 
                ret = nfcLoadAmiiboData();
                if(R_FAILED(ret))
                {
                    printf("nfcLoadAmiiboData() failed.\n");
                    break;
                }
 
                memset(&amiibosettings, 0, sizeof(NFC_AmiiboSettings));
                memset(&amiiboconfig, 0, sizeof(NFC_AmiiboConfig));
 
                ret = nfcGetAmiiboSettings(&amiibosettings);
                if(R_FAILED(ret))
                {
                    printf("nfcGetAmiiboSettings() failed.\n");
                    if(ret==NFC_ERR_AMIIBO_NOTSETUP)printf("This amiibo wasn't setup by the amiibo Settings applet.\n");
                    break;
                }
 
                ret = nfcGetAmiiboConfig(&amiiboconfig);
                if(R_FAILED(ret))
                {
                    printf("nfcGetAmiiboConfig() failed.\n");
                    break;
                }
 
                printf("amiibo data successfully loaded.\n");
 
                printf("amiiboconfig: lastwritedate year=%u month=%u day=%u.\n", amiiboconfig.lastwritedate_year, amiiboconfig.lastwritedate_month, amiiboconfig.lastwritedate_day);
                printf("amiiboconfig.write_counter=%u\n", amiiboconfig.write_counter);
 
                printf("Opening appdata...\n");
 
                appdata_initialized = 1;
 
                ret = nfcOpenAppData(amiibo_appid);
                if(R_FAILED(ret))
                {
                    printf("nfcOpenAppData() failed.\n");
                    if(ret==NFC_ERR_APPDATA_UNINITIALIZED)
                    {
                        printf("This appdata isn't initialized.\n");
                        appdata_initialized = 0;
                    }
                    if(ret==NFC_ERR_APPID_MISMATCH)printf("This appdata is for a different appid(non-Super-Smash-Bros).\n");
                    if(appdata_initialized)break;
                }
 
                memset(appdata, 0, sizeof(appdata));
 
                if(!appdata_initialized)
                {
                    printf("Skipping appdata reading since it's uninitialized.\n");
                }
                else
                {
                    printf("Reading appdata...\n");
 
                    ret = nfcReadAppData(appdata, sizeof(appdata));
                    if(R_FAILED(ret))
                    {
                        printf("nfcReadAppData() failed.\n");
                        break;
                    }
 
                    printf("Appdata:\n");
                    for(pos=0; pos<sizeof(appdata); pos++)printf("%02x", appdata[pos]);
                    printf("\n");
 
                    memset(tmpstr, 0, sizeof(tmpstr));
                    snprintf(tmpstr, sizeof(tmpstr)-1, "amiibo_appdata_out_%s.bin", uidstr);
 
                    printf("Writing appdata to file '%s'...\n", tmpstr);
                    f = fopen(tmpstr, "w");
                    if(f)
                    {
                        tmpsize = fwrite(appdata, 1, sizeof(appdata), f);
                        fclose(f);
 
                        if(tmpsize!=sizeof(appdata))
                        {
                            printf("Failed to write to the file, only 0x%x of 0x%x bytes were written.\n", tmpsize, sizeof(appdata));
                        }
                        else
                        {
                            printf("Writing finished.\n");
                        }
                    }
                    else
                    {
                        printf("Failed to open the file.\n");
                    }
                }
 
                if(hidKeysHeld() & KEY_A)
                {
                    memset(tmpstr, 0, sizeof(tmpstr));
                    snprintf(tmpstr, sizeof(tmpstr)-1, "amiibo_appdata_in_%s.bin", uidstr);
 
                    printf("Loading appdata from file '%s', which will be written to the amiibo...\n", tmpstr);
 
                    ret = 1;
 
                    f = fopen(tmpstr, "r");
                    if(f)
                    {
                        memset(appdata, 0, sizeof(appdata));
                        tmpsize = fread(appdata, 1, sizeof(appdata), f);
                        fclose(f);
 
                        if(tmpsize!=sizeof(appdata))
                        {
                            printf("Failed to read to the file, only 0x%x of 0x%x bytes were written.\n", tmpsize, sizeof(appdata));
                        }
                        else
                        {
                            printf("File reading finished.\n");
                            ret = 0;
                        }
                    }
                    else
                    {
                        printf("Failed to open the file.\n");
                    }
 
                    if(ret==0)
                    {
                        if(appdata_initialized)
                        {
                            printf("Writing the appdata...\n");
 
                            ret = nfcWriteAppData(appdata, sizeof(appdata), &taginfo);
                            if(R_FAILED(ret))
                            {
                                printf("nfcWriteAppData() failed.\n");
                                break;
                            }
 
                            printf("Writing to the amiibo NFC tag...\n");
 
                            ret = nfcUpdateStoredAmiiboData();
                            if(R_FAILED(ret))
                            {
                                printf("nfcUpdateStoredAmiiboData() failed.\n");
                                break;
                            }
                        }
                        else
                        {
                            printf("Initializing the appdata...\n");
 
                            ret = nfcInitializeWriteAppData(amiibo_appid, appdata, sizeof(appdata));
                            if(R_FAILED(ret))
                            {
                                printf("nfcInitializeWriteAppData() failed.\n");
                                break;
                            }
                        }
 
                        printf("Writing finished.\n");
                    }
                }
 
                printf("amiibo NFC tag processing has finished, you can\nremove the tag from NFC-range now.\n");
            }
        }
    }
 
    nfcStopScanning();
 
    return ret;
}
 
int main()
{
    Result ret=0;
 
    gfxInitDefault();
    consoleInit(GFX_TOP, NULL);
 
    printf("libctru nfc example.\n");
 
    ret = nfcInit(NFC_OpType_NFCTag);
    if(R_FAILED(ret))
    {
        printf("nfcInit() failed: 0x%08x.\n", (unsigned int)ret);
    }
    else
    {
        ret = nfc_test();
        printf("nfc_test() returned: 0x%08x.\n", (unsigned int)ret);
 
        nfcExit();
    }
 
    printf("Press START to exit.\n");
 
    // Main loop
    while (aptMainLoop())
    {
        gspWaitForVBlank();
        hidScanInput();
 
        u32 kDown = hidKeysDown();
 
        if (kDown & KEY_START)
            break; // break in order to return to hbmenu
    }
 
    gfxExit();
    return 0;
}