st25r3911b transparent mode example

[philipweiss]

Posted on October 31, 2017 at 19:51

Is there any sample code to put the ST25R3911B into transparent mode?  I have been unable to make the 

ST25R3911B output OOK in transparent mode.

I need this functionality because I'm implementing a proprietary protocol.

My configuration/use model:

• My circuit uses MCU_CLK as required for timing

• I configure the ST25R3911_REG_OP_CONTROL register to enable TX and disable RX

• I clear ST25R3911_REG_AUX_tr_am and set ST25R3911_REG_AUX_ook_hr in the ST25R3911_REG_AUX register to enable OOK.
• I execute the 0xDC command (ST25R3911_CMD_TRANSPARENT_MODE) to enable transparent mode.
• I configure the MOSI pin to push-pull output 
• I expect changes to MOSI to be reflected when I measure from RFO1 to RFO2, with an oscillating signal (MOSI high), or nothing (MOSI low).

But, unfortunately, I don't get any signal on RFO1/RFO2.

Any assistance would be greatly appreciated.

[Ulysses HERNIOSUS · Accepted solution]

Posted on December 14, 2017 at 15:28

Hello,

unfortunately ST does not have support code showing usage of transparent mode on ST25R3911B.

Looking through your procedure looks reasonable. Some paths to look into:

• You don't mention oscillator enabling 'en' bit: I assume you did that. Not getting any signal might sound like this.
• ook_hr should not be needed, I am not exactly aware what happens if ==1
• Please observe that /SS line is not going low again after the Enter Tansparent Mode command.

Regards, Ulysses

[philipweiss]

Posted on December 19, 2017 at 01:35

I'm sorry to hear that ST does not have any support for transparent mode.  I have been, however, able to make some changes to the code to make both transmit and receive work in transparent mode.

Thanks for your help.