The LAP and the UAP make the significant address part (SAP) of the Bluetooth Address. The LAP value uniquely identifies a Bluetooth device as part of the Access Code in every transmitted frame. This portion of Bluetooth Address is allocated by the vendor of device. The UAP value is used for seeding in various Bluetooth specification algorithms.

The App sends a string (in variable lengths) with multiple MAC addresses (from none to a total of twelve MAC addresses). The App is connected using Bluetooth Classic to one ESP Now Sender Module. The NAP value is used in Frequency Hopping Synchronization frames. Dear experts I am still a beginner and I have created an (MIT) Android App where I select/configure the ESP32 MAC addresses for my ESP NOW (one to many) broadcast network. Bluetooth Address Structureīluetooth Address consists of three parts: NAP, UAP and LAP. OUI prefixes are assigned by the Institute of Electrical and Electronics Engineers (IEEE).Īdditionaly to identification, Bluetooth Device Address is used to determine the frequency hopping pattern in radio communication between Bluetooth devices. It can be used to determine the manufacturer of a device ( Bluetooth MAC Address Lookup form). The upper half of a Bluetooth Address (most-significant 24 bits) is so called Organizationally Unique Identifier (OUI). Bluetooth Device Address (or BD_ADDR) is a unique 48-bit identifier assigned to each Bluetooth device by the manufacturer.īluetooth Address is usually displayed as 6 bytes written in hexadecimal and separated by colons (example - 00:11:22:33:FF:EE).

Convert mac address string into bytes