# Rtl8720dn藍芽可以同時連接幾個設備

**URL:** <https://forum.amebaiot.com/t/rtl8720dn/1445>\
**Category:** BT\
**Tags:** evb-bw16, 中文, rtl872xd\
**Created:** [September 26, 2022, 9:28am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445 "2022-09-26T09:28:11Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![tom.chen2017](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/tom.chen2017/32/1150_2.png) [@tom.chen2017](https://forum.amebaiot.com/u/tom.chen2017)\
**Post date:** [September 26, 2022, 9:28am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445/1 "2022-09-26T09:28:11Z")

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請問rtl8720dn最多可以同時連接幾個藍芽設備?  
另外有可以設定lesc的暫存器嗎?

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**Author:** ![wyy](https://avatars.discourse-cdn.com/v4/letter/w/bc8723/32.png) [@wyy](https://forum.amebaiot.com/u/wyy)\
**Post date:** [September 27, 2022, 2:11am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445/2 "2022-09-27T02:11:55Z")

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在 SDK 里同时开启 peripheral + central 模式，peripheral 可以连接一个，central 可以连接三个。  
RTL8720DN 支持 secure connect，但是我不明白你想要设定什么暂存器？

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<div class="post-metadata">

**Author:** ![tom.chen2017](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/tom.chen2017/32/1150_2.png) [@tom.chen2017](https://forum.amebaiot.com/u/tom.chen2017)\
**Post date:** [September 27, 2022, 3:03am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445/3 "2022-09-27T03:03:24Z")

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1.所以不像Nordic BLE可以同時一對七做資料溝通嗎?  
2.RTL8720DN 支持 secure connect,所以Default是與設備端(BLE v4.2以上)都是內定開啟,內部自行處理嗎?

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<div class="post-metadata">

**Author:** ![wyy](https://avatars.discourse-cdn.com/v4/letter/w/bc8723/32.png) [@wyy](https://forum.amebaiot.com/u/wyy)\
**Post date:** [September 27, 2022, 3:23am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445/4 "2022-09-27T03:23:09Z")

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1. 对，最多四个
2. secure connect 可以选择要不要用，用了就内部处理

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<div class="post-metadata">

**Author:** ![tom.chen2017](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/tom.chen2017/32/1150_2.png) [@tom.chen2017](https://forum.amebaiot.com/u/tom.chen2017)\
**Post date:** [September 27, 2022, 3:25am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445/5 "2022-09-27T03:25:35Z")

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謝謝您的答覆!  
secure connect 可以选择要不要用,這個要如何設定呢?

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<div class="post-metadata">

**Author:** ![wyy](https://avatars.discourse-cdn.com/v4/letter/w/bc8723/32.png) [@wyy](https://forum.amebaiot.com/u/wyy)\
**Post date:** [September 27, 2022, 7:03am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445/6 "2022-09-27T07:03:57Z")

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```auto
uint16_t auth_flags = GAP_AUTHEN_BIT_SC_FLAG;
gap_set_param(GAP_PARAM_BOND_AUTHEN_REQUIREMENTS_FLAGS, sizeof(_authFlags), &_authFlags);

```

`auth_flags` 可以从以下的选项选择一起用，如 `GAP_AUTHEN_BIT_BONDING_FLAG | GAP_AUTHEN_BIT_SC_FLAG`。

```auto
#define GAP_AUTHEN_BIT_NONE 0 //!< No authentication required.
#define GAP_AUTHEN_BIT_BONDING_FLAG 0x0001 //!< Bonding is required
#define GAP_AUTHEN_BIT_MITM_FLAG 0x0004 //!< Mitm is preferred
#define GAP_AUTHEN_BIT_SC_FLAG 0x0008 //!< Secure connection is preferred
#define GAP_AUTHEN_BIT_SC_ONLY_FLAG 0x0200 //!< Secure connection only mode for BLE is required
#define GAP_AUTHEN_BIT_FORCE_BONDING_FLAG 0x0100 //!< Force bonding is required

```

如果只接受 secure connect, `GAP_AUTHEN_BIT_SC_ONLY_FLAG` 必须和 `GAP_AUTHEN_BIT_SC_FLAG` 一起用。

其他选项看你有没有需要那个功能。

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<div class="post-metadata">

**Author:** ![tom.chen2017](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/tom.chen2017/32/1150_2.png) [@tom.chen2017](https://forum.amebaiot.com/u/tom.chen2017)\
**Post date:** [September 27, 2022, 8:19am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445/7 "2022-09-27T08:19:10Z")

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非常感謝你的協助!! 我打算用Arduino IDE開發,有問題再請教!! 謝謝!!!

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<div class="post-metadata">

**Author:** ![tom.chen2017](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/tom.chen2017/32/1150_2.png) [@tom.chen2017](https://forum.amebaiot.com/u/tom.chen2017)\
**Post date:** [September 30, 2022, 8:27am UTC](https://forum.amebaiot.com/t/rtl8720dn/1445/8 "2022-09-30T08:27:34Z")

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我在使用arduino ide BW16的WIFI 範例,有個問題,就是怎麼切換到5G頻段兩塊開發板互相傳輸資料呢? 有範例嗎?