Domenico Luciani - BLE NUCLEO observer

For academic purposes I have to work with BLE, a new technology often used nowadays, with a NUCLEO-F401RE board and the NUCLEO-IDB04A1 BLE extension board by ST

To test it I wrote a small software to discovery a BLE peripheral around me, I named it “BLE Observer”.

#include "mbed.h"
#include "BLE.h"

BLE ble;

void advCb(const Gap::AdvertisementCallbackParams_t *params) {
    printf("Adv peerAddr: [%02x %02x %02x %02x %02x %02x] rssi %d, ScanResp: %u, AdvType: %u\r\n",
        params->peerAddr[5],
	params->peerAddr[4],
	params->peerAddr[3],
	params->peerAddr[2],
	params->peerAddr[1],
	params->peerAddr[0],
	params->rssi,
	params->isScanResponse,
	params->type);
}

void main(void) {
    ble.init();
    printf("INIT\r\n");
    ble.gap().setScanParams(400, 300);
    ble.gap().startScan(advCb);

    while(true) {
        ble.waitForEvent();
    }
}

To use this software you need to import two libraries: BLE_API and X_NUCLEO_IDB0XA1. (Follow the previous post to know how to do this)

The first instruction ble.init() initializes the BLE module.

With ble.gap().setScanParams(400, 300); we set the scan params, as first parameter we set the interval (delay between scans) and as second parameter we set the window (how long scan).

With ble.gap().startScan(advCb); we start the scan operation passing datas to a callback function named advCb through a pointer to AdvertisementCallbackParams_t struct.

In the advCb function we print on the screen the peer address, rssi (received signal strength indicator) information, if is a scan response and the type of the advertising (ADV_CONNECTABLE, ADV_UNDIRECTED, ADV_DIRECT, etc.).

In the ever true while loop we waiting for an event.

Here the result:

ble1

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