Bluetooth® USB Adapter Class 1 Long Range – LM540
The LM540 Long Range Bluetooth® USB Adapter has a range of 800m when connected with a 2dbi Antenna
To confirm and prove the real-world performance of the adapter, LM Technologies tested the LM540 – Long Range Bluetooth® USB Adapter at the Eaton Dorney Olympic Rowing Club, as it offered a 2km flat open space in which to conduct accurate testing. As the site had been used as a part of the 2012 Olympics it continues to feature Olympic-class distance markers laid-out every 100m.
By connecting two LM540 – Long Range Bluetooth® USB Adapter’s LM performed tests on device discovery (device searching), device pairing along with connection and re-connection, for each of the 100m distance markers. An additional GPS reading was taken from each of the locations where a connection was dropped and a reconnection was not possible.
The environment on the test day was favourable; clear (somewhat murky) with good visibility and low winds, aiding in the achievement of the distances recorded. Bluetooth® is extremely environmentally sensitive and therefore although LM was additionally able to replicate its results on a separate test date, weather conditions that offer a less helpful environment would make it highly unlikely to achieve the full distance obtained in tests performed on ‘ideal’ days.
In an effort to best guide and advise customers, LM Technologies provides a rough link budget calculator that helps in promoting an understanding of the effect various obstacles may have on a wireless signal. Please note that this calculator is extremely rough and theoretical and should not be used as a real calculation of achievable distance; LM always recommends a real-world trial of wireless products to determine achievable distance and bit-rates: Wireless Link-Budget Calculator
Brief Specification / Antenna Selection
The LM540 – Long Range Bluetooth® v2.1 + EDR USB Adapter without antenna offers 15dBm output and, therefore, in order to continue to comply within EU and US standard radio emissions requirements it is advised to chose an antenna with no more than a 5dBi rating. The LM540 – Long Range Bluetooth® USB Adapter is packaged with a 2dBi antenna which should be sufficient for most applications.
The LM540 – Long Range Bluetooth® USB Adapter supports both standard Windows and Linux BlueZ stacks, however LM also offers the adapter with the option of an Embedded IVT key, enabling support for the IVT Bluesoleil Bluetooth® Stack, allowing for fast and simple connection to a Windows PC, along with support for the a range of profiles listed below:
- AVRCP, GAP, PAN, LAN, DUN, HID, FAX, SYNC FTP, HCRP, BIP, GEOP, SDAP, OPP, SPP, HSP/HFP, A2DP
- When used with IVT Bluesoleil IVT v8.x Software.
To check that an adapter was purchased with IVT embedded key please see our Wiki:
Bluetooth® USB Adapter Class 1 Long Range – LM540 works as a plug-and-play device with Windows 98, XP, Vista, 7, 8, 8.1 and Linux when using Blue Z and Blue Z drivers.