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O
otmar
Visitor II
June 17, 2014
Solved

Disable RF communication

  • June 17, 2014
  • 4 replies
  • 1538 views
Posted on June 17, 2014 at 11:27

Hi

I'm using the M24LR04 in Harvesting Mode to supply an STM32L151.

When the uC powers up, it reads data from an sensor and write them to the M24LR.

This is than read from an NFC Handheld.

My problem is, when the Handheld approaches, first the M24LR starts to communicate with the handheld, before the uC powers up and refreshes the Data.

So i want to disable the RF communication until the STM is on.

I know there is the M24SR devices which had the RF disable Pin, but unfortunately my App is ISO15693 (and not 

ISO 14443)....

Is there another possibility...

Thanx

regards

otmar

#vout #rf-wip-busy #m24lr #m24lr
    This topic has been closed for replies.
    Best answer by Anais GALLIGANI
    Posted on July 07, 2014 at 10:05

    Hi,

    What you can try to do is:

    -

             

    Let the Vout pin unconnected

    -

             

    Connect RF WIP/busy to a forward bias direction diode D1

    -

             

    And AC1 to a forward bias direction diode D2

    -

             

    D1,D2 connected to the same point, then to a resistance to a point A

    -

             

    Point A

    •  link a capacitance to the ground

    • Connected to your micro

    -

             

    And the VCC is connected to an I/O of the Micro in order to be driven

    -

             

    And VCC+ DSA+SCL, all connected to your sensor.

    Awaiting your feedback,

    Best Regards,

    ST NFC/RFID Dynamic tag support

    4 replies

    A
    Anais GALLIGANIAnswer
    Visitor II
    July 7, 2014
    Posted on July 07, 2014 at 10:05

    Hi,

    What you can try to do is:

    -

             

    Let the Vout pin unconnected

    -

             

    Connect RF WIP/busy to a forward bias direction diode D1

    -

             

    And AC1 to a forward bias direction diode D2

    -

             

    D1,D2 connected to the same point, then to a resistance to a point A

    -

             

    Point A

    •  link a capacitance to the ground

    • Connected to your micro

    -

             

    And the VCC is connected to an I/O of the Micro in order to be driven

    -

             

    And VCC+ DSA+SCL, all connected to your sensor.

    Awaiting your feedback,

    Best Regards,

    ST NFC/RFID Dynamic tag support

    O
    otmarAuthor
    Visitor II
    July 10, 2014
    Posted on July 10, 2014 at 15:08

    Hello

    Thanks for your reply

    Please can you check the attachment, so i don't misunderstood your circuit

    best regards

    otmar

    ________________

    Attachments :

    M24LRx_disable.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HtzA&d=%2Fa%2F0X0000000aaw%2FfJRKtYgUsYr.PFv84RtCr4LtstTq_txHRRNGXpWFId8&asPdf=false
    A
    Anais GALLIGANI
    Visitor II
    August 29, 2014
    Posted on August 29, 2014 at 10:40

    Hello,

    I dont see your attachment file?!

    Thanks,

    Have a nice day,

    ST NFC RFID dynamic tags support

    G
    GCari.2
    Visitor II
    January 19, 2021

    Hi,

    I'm facing the same problem discussed by @otmar​ but I didn't really understand Galligani's answer. Microcontroller is powered by energy harvesting Vout pin, so I can't leave it unnnected. Any ideas?

    Regards

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