Using AAT on NFC08a1

[CT-55555]

Hello everyone,
I am using an NFC08A1 for my project and I would like to use the AAT. I roughly understand what happens in the AAT algorithm. However, I don't get any noticeable improvement when I apply it. The range in particular remains almost the same.

An external antenna is used in the project and I would like to achieve optimum performance. Which default values do I have to change in the algorithm to achieve this? And when does it make sense to call the AAT? Later I want to switch between two readers. Is it necessery to call the function everytime I change the reader or is it possible to store the best configuration. 

Rgds

[Ulysses HERNIOSUS]

Hi,

two remarks here:

1. Did you disable the setting of AAT registers from analog config? Per default these are overwriting any tuned values....
2. On a well tuned board like the NFC08 without a strong detuning element there is likely not much of an effect. You can try to put a metal plate close and then you may see a difference of re-tuned vs un-tuned antenna. But don't expect a boost of multiple centimeters!

BR, Ulysses

[CT-55555]

Hi,

1. Did you mean this part of the rfal_analogConfigTbl.h: 

if not please let me know. 

2. I connected a external Antenna to the board using normal wires. The distance between the antenna and the board is now about 100 cm. I also placed different metall objects near the antenna. I think these are strong detuning elements. 

Rgds 

 

[Ulysses HERNIOSUS]

Hi,

ad 1) Yes, it is about these registers. Critical for you is not the setting in CHIP_INIT but the other settings in POLL_COMMON and LISTEN_*. I think in the GUI we are providing analog configs for playing with the AAT (which don't have these settings) - also mentioned in the AAT appnote.

ad 2. Are you having 1m in differential mode. Not sure how well this can work. Maybe @Travis Palmer can comment on this.

 

BR, Ulysses

[Roger SHIVELY]

Hello @CT-55555 ,

There has been a case created to resolve this question and we will be reaching out to you directly.

Regards,
Roger