PN532 in I2C : RF Level detector don't modify range

[DylanVautrin]

Hello, I'm using a PN532 in I2C, connected to an ESP32. I'm using VsCode and platformio. 

I'm trying to improve the range of the PN532 using the RF Level Detector register. I saw this issue : https://community.nxp.com/t5/NFC/PN532-antenna-sensitivity-from-software/td-p/1397246

But, it don't seem to be resolved. My issue is that, when I modify this register, I don't noticed any differences on range/behavior. I have the exact same range with the min and the max sensitivity.

Is there any other register I should modify to “enable” this one ? I'm using the library Wire.h, is it okay ? 

I cannot modify the antenna, so I must found i way to improve (a bit) the range.

Furthermore, I would like to get the RSSI too, but it seems not possible over I2C, right ? 

Can you help me please ? 

Thanks,

Best regards

[DylanVautrin]

Hello,

Thanks for your help,

Yes, maybe I didn't understand it well. It is not possible to improve a bit the range with this register ? 

I know, it is not for New Design, I'm trying to improve the existing design.

Thanks for you help.

Best regards.

[EduardoZamora]

Hi,

According to the Data Sheet, the RF level detector detects the presence of an external RF-field delivered by the antenna to the RX pin. You should be able to adjust the sensitivity using the bits RFLevel of CIU_RFCfg register, but the sensitivity depends on the antenna configuration and tuning.

To try to increase the sensitivity of the RF level detector, an amplifier could be activated by setting the bit RFLevelAmp in CIU_RFCfg to 1. Something important to remark is that during the CIU Power-down mode the additional amplifier of the RF level detector is automatically switched off to ensure that the power consumption is minimal. CIU_RFCfg is described in detail in Section 8.6.23.36 CIU_RFCfg register.

I will recommend you please check the AN1425 RF Amplifier for NFC Reader IC's; this App Note provides guidance on antenna and RF amplifier design for NFC reader devices such as PN5xx.

Regards,
Eduardo.

[EduardoZamora]

Hello @DylanVautrin

Hope you are doing well.

Could you please confirm that you have read the PN532 Data Sheet, Section 8.6.8 RF level detector? Setting, registers and some considerations are discussed there. However, the sensitivity itself depends on the antenna configuration and tuning.

Please, consider that PN532 is Not Recommended for New Designs. For new designs, we recommend using PN7160. If you are still planning to use this device that is Not Recommended for New Designs, please keep in mind that you may face some supply issues in a future.

Regards,
Eduardo.