NFCのアンチコリジョン

タグ（NFCカードなど）が複数あり1つのリーダー（PaSoRiなど）で混線することなく情報を取得する機能

やりたいのは Type-A Type-2 のMifare Ultralight

衝突防止方式(アンチ・コリジョン)：ビット・コリジョン、タイム・スロット

The part A of the norm ISO 14443 is based on a principle well-adapted to wired-logic cards: cards should answer in a synchronic manner and the reader is able to determine precisely on which byte the first collision occurs.

It generates a new research frame where it indicates the beginning of this answer it has received, including this collision bit fixed randomly at 0.

If there is only two cards, the one of which the byte is at 1 will not answer and the reader will be able to receive the complete ID of the first card. It generates a new research frame and fixes the byte 1 and then obtain the ID of the second card. If there are many cards, you just need to repeat this mechanism as often as necessary to explore deeply all of the present ID.

よくわかってない

有用そう

ビットコリジョンをどうするべきか

「衝突ビット」ってどうやって判定するんだろう

アンチコリジョン周りについてはデバイスに依存している？