Ich habe momentan keine Arduino IDE zur Hand, aber müsste es nicht mit dem Befehl PCD_SetAntennaGain möglich sein, die Antennenleistung über die Tonuinosoftware direkt zu ändern?
Dort findet man folgenden Satz:
Increase the antenna gain per firmware:
mfrc522.PCD_SetAntennaGain(mfrc522.RxGain_max);
Aus der Lib void PCD_SetAntennaGain(byte mask);
// MFRC522 RxGain[2:0] masks, defines the receiver's signal voltage gain factor (on the PCD).
// Described in 9.3.3.6 / table 98 of the datasheet at http://www.nxp.com/documents/data_sheet/MFRC522.pdf
enum PCD_RxGain : byte {
RxGain_18dB = 0x00 << 4, // 000b - 18 dB, minimum
RxGain_23dB = 0x01 << 4, // 001b - 23 dB
RxGain_18dB_2 = 0x02 << 4, // 010b - 18 dB, it seems 010b is a duplicate for 000b
RxGain_23dB_2 = 0x03 << 4, // 011b - 23 dB, it seems 011b is a duplicate for 001b
RxGain_33dB = 0x04 << 4, // 100b - 33 dB, average, and typical default
RxGain_38dB = 0x05 << 4, // 101b - 38 dB
RxGain_43dB = 0x06 << 4, // 110b - 43 dB
RxGain_48dB = 0x07 << 4, // 111b - 48 dB, maximum
RxGain_min = 0x00 << 4, // 000b - 18 dB, minimum, convenience for RxGain_18dB
RxGain_avg = 0x04 << 4, // 100b - 33 dB, average, convenience for RxGain_33dB
RxGain_max = 0x07 << 4 // 111b - 48 dB, maximum, convenience for RxGain_48dB
};