Bluetooth®

About Bluetooth®

Bluetooth® wireless technology is one of the most pervasive low power radio technologies and is a common feature of mobile phones, tablets, laptops and games systems.

Bluetooth® wireless technology uses short-range radio links in order to build up Personal Area Networks (PANs) that can link together several devices to allow for the easy transfer of audio and other low-bandwidth data between them. Bluetooth is an open standard that is controlled by the Bluetooth Special Interest Group (SIG). Bluetooth is supported by almost all new smartphones and tablets, and by many laptops.

The Bluetooth® protocol is comprised of a core protocol and a set of layered profiles that allow for efficient device specialisation. The best-known profiles are the Advanced Audio Distribution Profile (A2DP), the Audio / Visual Remote Control Profile (AVRCP), the Hands Free Profile (HFP), the Headset Profile (HSP), the Human Interface Devices (HID) profile and the Serial Port Profile (SPP), but there are many others.

Our Expertise
Between them, our staff members have many years of experience of working with Bluetooth®, and have contributed to the development of the core specifications, to the profiles, to the baseband implementation of major Bluetooth chip vendors and of end products. In fact, a number of our staff members previously worked for the leading Bluetooth chip vendor, CSR plc (now part of Qualcomm).

How We Can Help You
With our in-depth knowledge of the Bluetooth protocol and of the Bluetooth industry, we are ideally placed to help you develop the products you want. We can help you analyse your requirements and tailor them to work within the constraints of the Bluetooth specification. We can design and develop your Bluetooth wireless software at all layers up to (and including) the application and we can cater for stack configurations including:

• Full stack, profiles and application on-chip
• Full stack on-chip with profiles and application on separate host via a host stack
• Stack to HCI on-chip, all above HCI on separate host via a host stack
• Custom software on-chip with a companion Windows and/or macOS application, including DFU support via USB
• Custom software on-chip with a companion app for Android and/or iOS, including OTA-DFU support
• Custom Bluetooth® Low Energy software

We will make sure that what is delivered will work for you and will work alongside existing Bluetooth systems. We can support our customers through acceptance testing and qualification of the software system.

A2DP and AVRCP

The Advanced Audio Distribution Profile (A2DP) allows high quality stereo audio to be transferred from a source device to an audio rendering device (such as speakers or a headset). Alternatively, A2DP can be used to transfer audio at reduced quality (down to at voice quality in mono) with a reduced radio bandwidth requirement compared to HFP.

The Audio / Visual Remote Control Profile (AVRCP) allows for media control commands, such as play and pause, to be sent between devices. It is often used in parallel with A2DP to, say; enable a headset to control a media player.

Our Expertise
Our staff have been involved in the development of many devices that support A2DP and/or AVRCP ‐ such as the motorcycle headset. We can utilise this previous experience to quickly and efficiently develop further A2DP / AVRCP devices that are tailored to your requirements.

HFP / HSP

The Hands Free Profile (HFP) and the Headset Profile (HSP) are two alternative profiles for connecting a hands-free device or headset to a mobile phone, and allow for functionality such as last number redial.

Our Expertise
Our staff have been involved in the development of many devices that support HFP and/or HSP ‐ such as the motorcycle headset. We can utilise this previous experience to quickly and efficiently develop further HFP / HSP devices that are tailored to your requirements.

HID

The Human Interface Devices (HID) profile provides a means for HID devices (such as keyboards, mice and games controllers) to connect to computers, smartphones, tablets, games consoles, etc. The HID profile can also, in some cases, be used to transfer small amounts of control or status information between devices.

Our Expertise
Our staff has been involved in the development of a number of HID devices and HID hosts, such as for a Bluetooth-powered smart whiteboard. We can utilise this previous experience to quickly and efficiently develop further HID devices that are tailored to your requirements.

SPP

The Serial Port Profile (SPP) is designed to offer a wireless replacement for RS232-type serial communications. As well as having many industrial applications, SPP is supported by most smartphone platforms to allow custom phone apps to interact with Bluetooth accessories that offer data or control/monitoring services ‐ such as app-accompanied Bluetooth speakers and universal remote controls.

Our Expertise
Our staff have been involved in the development of many commercial, industrial and consumer products that utilise SPP. These products include industrial control / monitoring systems and speaker systems that use SPP to offer a more sophisticated control and configuration channel than can be provided by the AVRCP profile. Furthermore, one of our particular areas of speciality is in developing Bluetooth accessories for multiple smartphone platforms using SPP for Android phones and iAP for Apple products. See here for more details.

Apple iAP

Apple’s iPod Accessory Protocol (iAP) is a proprietary protocol that was originally used to allow iPods to communicate with accessory products via the iPod’s dock connector. It is now supported by all iOS devices and is supported via Bluetooth as well as over the dock connector.
The iAP protocol defines a number of “lingos” for applications such as data storage and location. It also defines a general lingo that can be used to fill a similar role to the Serial Port Profile.

Our Expertise
We have developed a number of products targeting Apple’s iOS devices, including speaker products that support sophisticated audio control via both the dock connector and via Bluetooth. Other iOS-targeted products that we have developed include the Remote Control for iPhone, iPod or iPad. See here for more details.

GATT and Bluetooth® Low Energy

Bluetooth® Low Energy (BLE; previously known as Bluetooth Smart) is a reduced-power version of Bluetooth that is targeted at low-bandwidth (non-streaming) applications. GATT (the Generic Attribute Profile) provides profile discovery and description services for Bluetooth Low Energy.

For more information, see here.

DFU and OTA-DFU

Device Firmware Upgrade (DFU) is an industry-standard way of updating the software contained within an embedded device. The DFU software update process is typically driven by a PC with the embedded device connected via USB. Alternatively, the DFU process may be driven via USB or a UART from a microcontroller that is embedded within the same product as the Bluetooth chip.

Over-The-Air DFU (OTA-DFU) is a similar process that sends the software update wirelessly, typically via Bluetooth® Low Energy, SPP and/or iAP. This is typically driven from a smartphone app.

Our Expertise
Most of the products we develop include support for DFU software updates, via either USB or OTA (or both). We are also able to provide customised smartphone apps to drive the OTA-DFU process and Windows applications for the USB DFU process. Finally, we can also offer a set of tools to allow DFU functionality to be integrated into our customers’ Mac OS X applications ‐ see here for details.

Bluetooth Qualification

All products that use Bluetooth® must complete the Bluetooth Qualification Process. This is a means of ensuring that all Bluetooth products are correctly implemented (ensuring device interoperability) and that they properly comply with the Bluetooth License Agreement. For more information, see the Bluetooth Special Interest Group (SIG) website.

Our Expertise
We have successfully taken many products through the Bluetooth Qualification Process and so understand how to design and implement products to ensure an easy passage through this process.