nRF51822-新手入门笔记

Bertha 。 2022-08-01 11:23 356阅读 0赞

\[群150178878\]nRF51822-新手入门笔记【1】  
转自： http://www.eeboard.com/bbs/thread-40359-1-1.html  
这是1年前入门时记的笔记，有些问题很简单很入门，不过懒得修改了，使用的是旧版SDK，原理一样，希望对大家有帮助，后面的笔记比较乱，抽空继续整理一下，  
  
为了防止个人理解错误，下面的回答大多都会引用了论坛资料或者链接。  
**1.如何让设备发起bongding请求**  
先设置权限BLE\_GAP\_CONN\_SEC\_MODE\_SET\_ENC\_NO\_MITM(&dis\_init.dis\_attr\_md.read\_perm)  
在ios上，除非app试图读取的characteristic收到保护，否则是没有bongding请求发生的。(可参考ble\_app\_gls例程)  
  
原回答如下：  
On iOS, no bonding will occur unless an app tries to read a characteristic that is **protected**. If you use LightBlue, **this** app will not **do** any such reads unless you specifically asks it to. To trigger bonding, you should therefore make sure to navigate the services/characteristics in such way that either a **protected** read or write is triggered, which again should trigger bonding.  
  
authorization doesn't have anything to do with bonding, it's just a way **for** the application to know and authorize each read/write.  
The protection I mean is the one set with the BLE\_GAP\_CONN\_SEC\_\* macros. If you **try** to read any characteristic that is set as **for** example BLE\_GAP\_CONN\_SEC\_MODE\_SET\_ENC\_NO\_MITM(), **this** will trigger bonding.  
  
  
  
**2.如何添加用户自己的128bit UUID?**  
使用sd\_ble\_uuid\_vs\_add(param1, param2)函数添加自己的128bit的service或者UUID，6.0的softdevice固件支持添加最多10个128bitUUID。param1是16byte用户uuid, param2存放softdevice分配的UUIDtype, 从BLE\_UUID\_TYPE\_VENDOR\_BEGIN(0x02)开始算,总共能添加10条,以后每一条只需要这个vender uuid type就行.  
注意，param1的第13，14byte 不用写也行，写了也没用，后面还需添加。  
     /\* 范例 \*/  
    ble\_uuid128\_t  uuid\_128bits = \{0xD0, 0x00, 0x2D, 0x12, 0x1E, 0x4B, 0x0F, 0xA4, 0x99, 0x4E, 0xCE, 0xB5, 0, 0, 0x05, 0x79\};  //中间两个0xF431，这是苹果的    ANCS service base uuid  
    ble\_uuid\_t  ble\_uuid;  
    uint8\_t uuid\_128bit\_type; //此变量存放softdevice分配的 UUID type  
  
    ble\_uuid.uuid = 0xF431;  
    err\_code = sd\_ble\_uuid\_vs\_add(&uuid\_128bits, uuid\_128bit\_type);  
    err\_code = sd\_ble\_gatts\_service\_add(BLE\_GATTS\_SRVC\_TYPE\_PRIMARY, &ble\_uuid, &p\_me\->service\_handle);  
  
  
  
**3.如何发现ios的ANCS的service以及characteristic?**  
(1)使用函数sd\_ble\_uuid\_vs\_add()添加central的128bit UUID  
(2)使用GATTC相关的函数查找service以及characteristic  
   sd\_ble\_gattc\_primary\_services\_discover()  
   sd\_ble\_gattc\_characteristics\_discover()  
  
  
**4.如何清除绑定?**  
在static void bond\_manager\_init(void)函数中  
     // Initialize the Bond Manager  
    bond\_init\_data.flash\_page\_num\_bond     = FLASH\_PAGE\_BOND;  
    bond\_init\_data.flash\_page\_num\_sys\_attr = FLASH\_PAGE\_SYS\_ATTR;  
    bond\_init\_data.evt\_handler             = NULL;  
    bond\_init\_data.error\_handler           = bond\_manager\_error\_handler;  
    bond\_init\_data.bonds\_delete            = **true**; //此处可以清除绑定  
  
    err\_code = ble\_bondmngr\_init(&bond\_init\_data);  
    APP\_ERROR\_CHECK(err\_code);  
  
  
通过ble\_bondmngr\_init()函数, 即初始化了绑定参数,又同时清除了之前的绑定  
  
**5.APP\_BUTTON\_INIT 拿来什么用?和普通的引脚初始化有什么不同?**  
原型: APP\_BUTTON\_INIT(BUTTONS, BUTTON\_COUNT, DETECTION\_DELAY, USE\_SCHEDULER)   
用于设置特定引脚作为button, USE\_SCHEDULER参数决定是否调用button\_handle函数  
示例:  
**static** **void** buttons\_init(**void**)  
\{  
    **static** app\_button\_cfg\_t buttons\[\] =  
    \{  
        \{HR\_INC\_BUTTON\_PIN\_NO, **false**, NRF\_GPIO\_PIN\_PULLUP, button\_event\_handler\},  
        \{HR\_DEC\_BUTTON\_PIN\_NO, **false**, NRF\_GPIO\_PIN\_PULLUP, button\_event\_handler\}  // Note: This pin is also BONDMNGR\_DELETE\_BUTTON\_PIN\_NO  
    \};  
  
    APP\_BUTTON\_INIT(buttons, **sizeof**(buttons) / **sizeof**(buttons\[0\]), BUTTON\_DETECTION\_DELAY, **false**);  
\}  
  
  
该函数底层用到app\_timer\_create(); 用32.768低功耗定时器来检测按键是否发生.  
  
**6.如何保护Flash程序不被读取?**  
NRF\_NVMC\->CONFIG = 1;  //开启FLASH写权限(写UIRC)  
**while** (NRF\_NVMC\->READY == NVMC\_READY\_READY\_Busy)  
\{  
    // Do nothing.  
\}  
NRF\_UICR\->RBPCONF = 0x00000000;  
NRF\_NVMC\->CONFIG = 0;  
  
  
  
**7.advertising\_init()函数中的广播数据中的flag应该怎么设置, Scan Response是否需要设置flag?**  
flags must be included in advertising data,  
and the BLE\_GAP\_ADV\_FLAG\_BR\_EDR\_NOT\_SUPPORTED flag must be set  
Advertising Data 必须设置flag, 设置对了其他的广播数据自由选择.  
Scan Response Data不需要设置flag否则会出错  
  
**8.如何广播128bit UUID?**  
首先建议在main()函数中添加本次工程需要用到的所有的128bit vender service base uuid, 而且添加时必须放在ble\_stack\_init()函数后,因为该函数启动了softdevice. (我把它放在all\_vs\_uuid\_add()函数中, 在main()函数中调用)  
**static** **void** all\_vs\_uuid\_add(**void**)  
\{  
    uint32\_t err\_code;  
    ble\_uuid128\_t uuid\_128bits = RBL\_SHIELD\_UUID\_BASE; //16byte 数据  
  
    err\_code = sd\_ble\_uuid\_vs\_add(&uuid\_128bits, &ble\_rbl\_shield.uuid\_type);  
    APP\_ERROR\_CHECK(err\_code);  
\}  
广播的128bit vender service uuid可以放在advertising data中也可以放在scan response data中  
**static** **void** advertising\_init(**void**)  
\{  
    uint32\_t      err\_code;  
    ble\_advdata\_t advdata;  
    uint8\_t       flags = BLE\_GAP\_ADV\_FLAGS\_LE\_ONLY\_GENERAL\_DISC\_MODE;  
    ble\_advdata\_t srdata;  
  
    ble\_uuid\_t adv\_uuids\[\] =  
    \{  
        \{0x0000,   ble\_rbl\_shield.uuid\_type\} //BLE\_UUID\_TYPE\_BLE ble\_rbl\_shield.uuid\_type  
    \};  
  
    // Build and set advertising data  
    memset(&advdata,  0, **sizeof**(advdata));  
  
    //同时在advertising data和scan response data中广播128bit vs uuid  
    advdata.flags.size              = **sizeof**(flags);  
    advdata.flags.p\_data            =  &flags;  
    advdata.uuids\_complete.uuid\_cnt = **sizeof**(adv\_uuids) / **sizeof**(adv\_uuids\[0\]);  
    advdata.uuids\_complete.p\_uuids  = adv\_uuids;    
  
    srdata.uuids\_complete.uuid\_cnt = **sizeof**(adv\_uuids) / **sizeof**(adv\_uuids\[0\]);  
    srdata.uuids\_complete.p\_uuids  = adv\_uuids;  
  
    err\_code = ble\_advdata\_set(&advdata, &srdata);  
    APP\_ERROR\_CHECK(err\_code);  
  
    // Initialize advertising parameters (used when starting advertising)  
    memset(&m\_adv\_params,  0, **sizeof**(m\_adv\_params));  
  
    m\_adv\_params.type        = BLE\_GAP\_ADV\_TYPE\_ADV\_IND;  
    m\_adv\_params.p\_peer\_addr = NULL;                           // Undirected advertisement  
    m\_adv\_params.fp          = BLE\_GAP\_ADV\_FP\_ANY;  
    m\_adv\_params.interval    = APP\_ADV\_INTERVAL;  
    m\_adv\_params.timeout     = APP\_ADV\_TIMEOUT\_IN\_SECONDS;  
\}  
  
  
如果遇到添加后程序错误, 那要注意, 因为128bit的uuid已经占了16bytes, 如果这时候你的local name或者你还广播了其他的UUID,超过了31bytes程序是会发生错误的.  
  
**9.为什么蓝牙连接上iphone后一会就自动断线了?**  
这里只说一种情况,  如果蓝牙的最大及最小的连接间隔设置的太小, 就会出现上述情况, 什么都不做但是过会会断线.iphone要求的连接间隔是：  
Interval Max  \* (Slave Latency \+  1) ≤ 2 seconds  
Interval Min ≥ 20 ms  
Interval Min \+ 20 ms ≤ Interval Max Slave Latency ≤ 4  
connSupervisionTimeout ≤ 6 seconds  
Interval Max \* (Slave Latency  \+ 1) \* 3 < connSupervisionTimeout  
  
  
我们可以定为20ms~40ms  
  
**10. 如何通过蓝牙传输大量数据?**  
询问FAE后得到的回答如下  
The easiest way to send large amounts of data is to send them sequentially as notifications.  
Add a characteristic that is 20 bytes **long** and has the notify property. Split your data in  20 byte chunks and call sd\_ble\_gatts\_hvx() repeatedly until you get the BLE\_ERROR\_NO\_TX\_BUFFERS back. At that time, wait until you get a BLE\_EVT\_TX\_COMPLETE, at which point you again can send data until you get the BLE\_ERROR\_NO\_TX\_BUFFERS. Repeat until all data has been sent.  
https://devzone.nordicsemi.com/index.php/dealing-large-data-packet-s-through-ble\#reply-1755  
  
  
有个ble event 宏定义为: BLE\_EVT\_TX\_COMPLETE, 收到这个事件就代表本次传输完毕.另外我们是通过sd\_ble\_gatts\_hvx()把待传输的数据尽可能地添加进tx buffer中去.  
  
**11.影响nRF51822(S110固件)数据传输速度的最大因素是什么?**