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Write data error over i2c bus with MFRC522

Question asked by philippstützel on Jan 30, 2018
Latest reply on Apr 13, 2018 by IvanRuiz

Hello,

 

I have here a RC522 MFRC522 RF Module IC Card Module which I try to access with an i2c connection.

I'm able to read the register and the values seem to be correct (e.g. Register 0x37 contains Version 0x92, which corresponds to data sheet)
Nevertheless I'm not able to write register, e.g. to change the gain. Gain value is stored in Register 0x26 with default 0x48. If I write e.g. 0x78 to the register, the command is send (checked with an i2c Beagle protocoll analyzer).
An again read return 0x48.
Furthermore I noticed that the command register contains the value 0x3F. According to the data sheet that means the device is in soft reset mode. Try to change this register value also fails.

Do someone have any suggestions where the error might be? Or what I'm doing wrong?

 

Thanks in advance

Best regards
Philipp

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