From welcoming people as they arrive at a sporting event to providing information about a nearby museum exhibit, iBeacon opens a new world of possibilities for location awareness, and countless opportunities for interactivity between iOS devices and iBeacon hardware.
Because the number of peripherals may be very large, developers can enable the **BLE Scan Duplicate Options**, the maximum number of devices in scan duplicate filter depends on the free heap size, when the cache is full, it is cleared.
### Event Processing
In the iBeacon receiver demo, the scan result will be posted to `ESP_GAP_SEARCH_INQ_RES_EVT` event:
The iBeacon sender will broadcast iBeacon packet after initializing the Bluetooth protocol stack, and the iBeacon receiver will scan the iBeacon packet.
### iBeacon Sender
```
I (384) boot: Loaded app from partition at offset 0x10000
I (384) boot: Disabling RNG early entropy source...
I (386) cpu_start: Pro cpu up.
I (389) cpu_start: Starting app cpu, entry point is 0x40081010
I (0) cpu_start: App cpu up.
I (400) heap_init: Initializing. RAM available for dynamic allocation:
I (406) heap_init: At 3FFAFF10 len 000000F0 (0 KiB): DRAM
I (413) heap_init: At 3FFCCCA8 len 00013358 (76 KiB): DRAM
I (419) heap_init: At 3FFE0440 len 00003BC0 (14 KiB): D/IRAM
I (425) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM
I (431) heap_init: At 40090E58 len 0000F1A8 (60 KiB): IRAM
I (438) cpu_start: Pro cpu start user code
I (120) cpu_start: Starting scheduler on PRO CPU
I (0) cpu_start: Starting scheduler on APP CPU
I (244) BTDM_INIT: BT controller compile version [44d04c1]
I (244) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
I (624) phy: phy_version: 3910, c0c45a3, May 21 2018, 18:07:06, 0, 0
I (654) IBEACON_DEMO: register callback
```
### iBeacon Receiver
```
I (384) boot: Loaded app from partition at offset 0x10000
I (384) boot: Disabling RNG early entropy source...
I (385) cpu_start: Pro cpu up.\0x1b[0m
I (389) cpu_start: Starting app cpu, entry point is 0x40081010
I (0) cpu_start: App cpu up.
I (400) heap_init: Initializing. RAM available for dynamic allocation:
I (406) heap_init: At 3FFAFF10 len 000000F0 (0 KiB): DRAM
I (412) heap_init: At 3FFCCC88 len 00013378 (76 KiB): DRAM
I (418) heap_init: At 3FFE0440 len 00003BC0 (14 KiB): D/IRAM
I (425) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM
I (431) heap_init: At 40090E58 len 0000F1A8 (60 KiB): IRAM
I (437) cpu_start: Pro cpu start user code\0x1b[0m
I (120) cpu_start: Starting scheduler on PRO CPU.
I (0) cpu_start: Starting scheduler on APP CPU.
I (243) BTDM_INIT: BT controller compile version [44d04c1]
I (243) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
I (633) phy: phy_version: 3910, c0c45a3, May 21 2018, 18:07:06, 0, 0
I (663) IBEACON_DEMO: register callback
I (329203) IBEACON_DEMO: ----------iBeacon Found----------