PM0237 datasheet(65/88 Pages) STMICROELECTRONICS

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DocID027104 Rev 2

65/88

PM0237

Design an application using BlueNRG, BlueNRG-MS ACI APIs

BONDING /* bonding is enabled */);

if (ret != BLE_STATUS_SUCCESS) PRINTF("Failure.\n")}

Once the security IO capability and authentication requirements are defined, an application

can initiate a pairing procedure as follow:

by using aci_gap_slave_security_request() on a GAP Peripheral (slave) device

(it sends a slave security request to the master):

tBleStatus ret;

ret = aci_gap_slave_security_request(conn_handle,

BONDING,

MITM_PROTECTION_REQUIRED

);

if (ret != BLE_STATUS_SUCCESS) PRINTF("Failure.\n")}

by using the aci_gap_send_pairing_request() on a GAP Central (master ) device.

Since the DONOT_USE_FIXED_PIN_FOR_PAIRING (no fixed pin) has been set, once the

paring procedure is initiated by one of the 2 devices, BlueNRG, BlueNRG-MS will generate

the EVT_BLUE_GAP_PASS_KEY_REQUEST event (with related connection handle) for asking to

the host application to provide the password to be used for establishing the encryption key.

BlueNRG, BlueNRG-MS application has to provide the correct password by using the

aci_gap_pass_key_response(conn_handle,passkey)API.

The following pseudocode example illustrates only the specific steps to be followed for

providing the pass key (for example a random pin) to be used for the pairing process, when

the EVT_BLUE_GAP_PASS_KEY_REQUEST event is generated on Device_1 (“Display Only”

capability) :

tBleStatus ret;

/* Generate a random pin with an user specific function */

pin = generate_random_pin();

ret = aci_gap_slave_security_request(conn_handle,

BONDING,

MITM_PROTECTION_REQUIRED

);

if (ret != BLE_STATUS_SUCCESS) PRINTF("Failure.\n")}

Since the Device_1, I/O capability is set as “Display Only”, it should display the generated

pin in the device display. Since Device_2 , I/O capability is set as “Keyboard Only”, the user

can provide the pin displayed on Device_1 to the Device_2 though the same

aci_gap_pass_key_response() API, by a keyboard.

PM0237 Datenblatt(PDF) 65 Page - STMicroelectronics