Fast transfer mode mailbox - how many write cycles can it handle?

[EGiff]

I have an application which must send > 100KB/day to an RFID/NFC reader (I'm using the STM25R Disco) - for days and years on end.

Looking at the EEPROM spec, it's good for 600k write cycles at 85 °C

(That means even at 64Kbit EEPROM, wear leveling would be critical for long life.)

The Fast Transfer Mode buffer / mailbox is intriguing (256 Bytes) - it seems perfect for my use case - (mainly polling data) - however I cannot find any information about the type of memory used for this or number of write cycles it supports in the datasheet.

So, what type memory is used for this FTM mailbox? How many write cycles can it handle?

Thank you very much

[EGiff]

"Try tuning for amplitude instead of phase using manual tuning." Do you mean changing ST25R3911 firmware(in rfal_analogConfigTbl.h) or others?

I mean the antenna tuning circuit can tune for either Phase over Amplitude, Amplitude over Phase or AAT (hardware) - setting the appropriate trim level accordingly.

To manually tune for amplitude or phase, you can sweep the trim values - and choose the highest one. (that's done on the PC using the software, or on the ST25R using AAT hardware method).

Once you have found the ideal trim value, you can set it like this:

// value must be minimum 0, maximum 15

void setTrimValue(uint8_t trim)

{

//logUsart("setTrimValue: %u", trim);

// See page 77 of ST25R3911B data sheet "Antenna calibration control register"

// Bit 7 (the first on the left) - indicates if the tuning was automatic or manual

// This will be 1 since we are setting it manually

// The next 4 bits give the trim value, from 0 to 15

// ex trim 8 = 1 1000 000 or 0xC0

uint8_t regVal = trim << 3; // align with register

regVal |= 0x80; // add manual adjust bit

st25r3911WriteRegister(0x21, regVal);

}

[EGiff]

Specifically, if you want max V_EH on the tag - would be to measure V_EH with a multi-meter on the tag for all the trim values.

[EGiff]

However, if your RSSI (measurable on the ST25R) is too low, V_EH (if turned on) - will be a fairly static value. Only above an RSSI of about 1.5V will E_VH start to increase

[johnson jiang]

Hello evan:

Thanks very much.

I tried your methods, but the distance doesn't increase.

I decide to change the reader from ST25R3911B to ST25R3916.

And ST25R3916 board will be available in the next week.

I get another issue, when the reader first read data from the tag in the mailbox mode, it takes such a long time(about 40 seconds) to get the right data.

Johnson

[asant.1]

ST25r3911b dll WITH sendreceive for c/c++

Good morning,

we are using your evm ST25R3911 buth we found only a dll demod that include only first command as RQA/ANTICOLL/SEL/PPS but not a SEND and receive as showed in your GUI ST tag editor, because I need to write A NDEF file but using a program in c/c++. Could you support us?

[Ulysses HERNIOSUS]

Hi asant.1,

I think this post is completely unrelated to the original post. Please open a new ticket and we will provide guidance.

Regards, Ulysses