Accept or reject bluetooth connection

Question

Hello everyone, the sdk version that I use is 15.0 (nrF5_SDK_15.0.0). The soft device is s132. 
 I need to make an android custom app (with UART functionality) so that only users with passkey can access . Where do I have to modify? in the Android app or in the nRF52 module. 
 Why I can not connect the UART sample (inside the nRF Toolbox Android app) with the example of ble_peripheral / ble_app_hrs? 
 How does the Android app know that the request comes from one nRF52 example or another? Where is acceptance made? I n the app or in the module? 
 Thanks

AndreasF · Accepted Answer

Hi. 
 If you want to use a passkey, you can look at the Glucose Application Example . This example secures bond by using Man-in-the-Middle protection (MITM). 
 You modify this in the project you compile to the .hex file you program your nRF52 device with. 
 I have just tested this on the ble_peripheral\ble_app_hrs example, and i did the following: 
 Add the following in the header in main.c : 
 #define SEC_PARAM_BOND 1 /**< Perform bonding. */

#define SEC_PARAM_MITM 1 /**< Man In The Middle protection required. */

#define SEC_PARAM_IO_CAPABILITIES BLE_GAP_IO_CAPS_DISPLAY_ONLY

#define SEC_PARAM_OOB 0

#define SEC_PARAM_MIN_KEY_SIZE 7

#define SEC_PARAM_MAX_KEY_SIZE 16

#define PASSKEY_TXT "Passkey:"

#define PASSKEY_TXT_LENGTH 8

#define PASSKEY_LENGTH 6

#define STATIC_PASSKEY "123456"

static ble_opt_t ble_opt; 
 You can change your passkey by configuring STATIC_PASSKEY and PASSKEY_LENGTH 
 Add the following in the function static void gap_params_init(void) in main.c : 
 uint8_t passkey[] = STATIC_PASSKEY;

BLE_GAP_CONN_SEC_MODE_SET_ENC_WITH_MITM(&sec_mode);

ble_opt.gap_opt.passkey.p_passkey = passkey;

err_code = sd_ble_opt_set(BLE_GAP_OPT_PASSKEY, &ble_opt);

APP_ERROR_CHECK(err_code); 
 You need to remove this from the same function: 
 BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode); 
 Since this line of code sets the link open, as you can read here . 
 Just compile and download. Open nRF Connect, and scan for devices. 
 
 Connect to Nordic_HRM. Click then on the options buttion on the right side off Peripheral . 
 
 Click on " Pair.. ", select Perform bonding, and click Pair . 
 You should then get a new window where you type your passkey, like shown under: 
 
 After you have clicked on Submit , the BLE link should now be bonded and encrypted as you see below: 
 
 I'm not sure what you mean with your second question, have you used the right parameters for UART? 
 You can find the UART example explained here , with setup and testing explained. 
 Your last question: 
 If you want to be sure that your devices pair and nobody eavesdrop the information, you have to use a security measurement such as a passkey, numeric comparison, OOB etc. 
 Good luck. 
 
 - Andreas

Accept or reject bluetooth connection

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