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danilo
Visitor II
October 18, 2013
Solved

Enabling M24LR16E-R Energy Harvester

  • October 18, 2013
  • 1 reply
  • 918 views
Posted on October 18, 2013 at 11:58

Hi to all,

I'm using a self-made eval board based on the M24LR16E-R dual EEPROM chip. It is very simple as it consists of the EEPROM chip, filter capacitors, pull-up resistors and, obviously the antenna.

RF signal is received by the same 15x15mm double layer antenna used in ANT7-M24LR16E.

As the energy harvester is disabled by default, I tried to enable it by writing the config byte using I2C interface. More precisely:

_ I set bit E2 =1 and bit RW = 0 in the device select code

_ I set the bit EH_mode = 0 in the Config byte at address 2320h

The I2C communication happens as follow:

START -> DEV.SELECT -> ADDR MSB -> ADDR LSB -> CONF.BYTE -> STOP

All the byte sent (address and data) have been acknowledged correctly, but the energy harvester results still disabled.

Any help?

Kind regards

D.Porcarelli

P.S: as RF transmitter I'm using the transnmitter in the M24LR discovery kit. The attached file is a screenshot of the SDA and SCL signals

#m24lr16e
    This topic has been closed for replies.
    Best answer by Anais GALLIGANI
    Posted on November 05, 2013 at 18:00

    Dear Customer,

    Thanks for your inquiry.

    The process described in your request  to modified the EH_MODE value seems to be OK. Perhaps the issue is due to the address of the byte to modiy :

    You speak about 2302h … but I don’t know if it is Hexadecimal or Decimal value. You need to use Hexadecimal value of 2320d Decimal address : the address of EH_MODE byte is  0x0910.

    The I2C sequence is :

                    < START 0xAE readACK 0x09 readACK 0x10 readACK 0xF3  read Ack STOP >

     (my previous settings was 0xF7 so I send 0xF3)

    Just to be sure that you are aware of this config bit EH_MODE (BOOT ON/OFF) use : with this bit, the EH will not appears directly, but in case of RF OFF .. RF ON, the EH will be activated by default.

    So after changing this bit, you need to remove from RF field and enter again in RF field to activate Energy Harvesting.

    To set/reset directly Energy Harvesting, the a write address 0x920 will be needed.

    Thanks for thinking ST !

    ST NFC/RFID Dynamic tag support 

    1 reply

    A
    Anais GALLIGANIAnswer
    Visitor II
    November 5, 2013
    Posted on November 05, 2013 at 18:00

    Dear Customer,

    Thanks for your inquiry.

    The process described in your request  to modified the EH_MODE value seems to be OK. Perhaps the issue is due to the address of the byte to modiy :

    You speak about 2302h … but I don’t know if it is Hexadecimal or Decimal value. You need to use Hexadecimal value of 2320d Decimal address : the address of EH_MODE byte is  0x0910.

    The I2C sequence is :

                    < START 0xAE readACK 0x09 readACK 0x10 readACK 0xF3  read Ack STOP >

     (my previous settings was 0xF7 so I send 0xF3)

    Just to be sure that you are aware of this config bit EH_MODE (BOOT ON/OFF) use : with this bit, the EH will not appears directly, but in case of RF OFF .. RF ON, the EH will be activated by default.

    So after changing this bit, you need to remove from RF field and enter again in RF field to activate Energy Harvesting.

    To set/reset directly Energy Harvesting, the a write address 0x920 will be needed.

    Thanks for thinking ST !

    ST NFC/RFID Dynamic tag support 

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