我用ACR 122之前，它准确无误地运行与Android的＆LT; 4.1手机。我用它来交换的P2P SNEP messsages ......但自从手机拿到4.1，读卡器会发出哔音，当你把它放在手机上面闪烁。没有任何人发现这个不兼容？任何解决办法？

I used the ACR 122 before and it worked flawlessly with an Android < 4.1 phone. I used it to exchange P2P SNEP messsages... But since the phone got 4.1, the reader starts beeping and flashing when you place the phone above it. Does anyone else have found this incompatibility? Any solutions?

推荐答案

由于Android 4.1果冻豆，NFC的对等通信配置为使用较高的比特率（212 kbps的），而先前它是使用速率为106 kbps（在安装有谷歌钱包Android设备它总是使用212 kbps的）。

Since Android 4.1 Jelly Bean, NFC peer-to-peer communication is configured to use a higher bitrate (212 kbps), while earlier it was using 106 kbps (in Android devices that have Google Wallet installed it was always using 212 kbps).

我不知道ACR122U是否可以支持通过 javax.smartcardio 的较高的比特率。 NFC芯片内（恩智浦的PN532)当然可以做到这一点。低级别的ISO18092 / ECMA-340协议，212和424 kbps的是106 kbps的差异，随着106 kbps的，它使用相同的调制为ISO14443，而较高的比特率使用相同的调制方式的FeliCa（见页 7和标准 8）。因此，我怀疑这不能通过 javax.smartcardio 处理。

I don't know whether the ACR122U can support the higher bitrate through javax.smartcardio. The NFC chip inside (NXP's PN532) can certainly do it. The low-level ISO18092/ECMA-340 protocol for 212 and 424 kbps is different from 106 kbps. With 106 kbps it uses the same modulation as ISO14443, while the higher bitrates use the same modulation as FeliCa (see page 7 and 8 of the standard). So I suspect this cannot be handled through javax.smartcardio.