and I want to connect it to a existing controller board via UART port.
I have cut circuit board track to pin 32 of MFRC522 chip to enable UART interface.
I have verified with multimeter voltage on pin 32 of MFRC522 is 0V.
I have noted that message sent on RX pin (named SDA on RFID board connector) are present also on TX pin (named MISO on board connector) as the is a link between these pins...
MFRC522 do not elaborate message sent on RX pin, simply retransmit it on TX pin.
What is wrong ?
Please help me
Thank you
Try connecting EA (pin 32) to GND, don't rely on the 0V indication.
If you touch GND on the board with one tip of the multimeter and with the other you touch your table, the multimeter still shows 0V but that doesn't mean that the table is connected to GND, right?
How about a partial schematic showing what you proposed to do. I have lots of boards but they do not look the same. Also links to technical information always helps.
The data sheet says that pin 32 is for changing the I2C address. Who told you otherwise?
Please see the data sheet in section 8.1 for how to change the output interface. But I always assumed that outputs other than SIP were not available due to the way the board is laid out and it is not something you can correct, although I could be wrong.
Pin 31 when the interface is configured correctly is the pin where the output will appear. Pin 24 will be the serial input, and Pin 29 is the UART request to send DTRQ for serial handshaking. I am not sure how you set the serial baud rate.
Also note these signals will be a 3V3 level so might need level shifting before you can drive an Arduino Serial input.
Hi,
MFRC522 datasheet states that pin 1 (I2C) and pin 32 (EA) of MFRC522 can be used to select communication interface.
UART can be selected by connecting Pin 1 and pin 32 of MRC522 to GND.
I am using not Arduino but a microcontroller board with 3,3V RXD and TXD levels.
