nRF51824 - World's most capable automotive qualified Bluetooth SoC
The nRF51824 is now available qualified to AEC-Q100 for automotive applications that demand AEC-Q100 qualified devices. The nRF51824 is a fully featured nRF51 series SoC with 256kB flash and 16kB RAM in a 48-pin 6mm x 6mm QFN package. It is pin compatible with the nRF51822 and nRF51422 SoCs. This device has the standard nRF51 series software architecture and as such there is a wealth of software available for development with this device, both from Nordic and from the vibrant nRF51 series development community. It is compatible with the Bluetooth 4.2 qualified S130 SoftDevice which offers up to 8 concurrent links and supports all 4 Blutooth low energy roles (Central/Peripheral/Broadcaster/Observer).
AEC-Q100
AEC-Q100 is a failure mechanism based stress test qualification for packaged integrated circuits. The Automotive Electronics Council (AEC) is an organization based in the USA that sets the standards for the supply of components in the automotive electronics industry. Originally formed by Chrysler, Ford and Delco Electronics it now comprises members from many different companies that span car makers through system suppliers to component manufacturers. In regard to automotive electronics there are 3 notable qualification standards:
- AEC-Q100 “Stress test qualification for integrated circuits”
- AEC-Q101 “Stress test qualification for discrete electronic components”
- AEC-Q200 “Stress test qualification for passive electronic components”
The qualification includes a range of stress testing that includes physical, electrical and temperature tests. Integrated circuit suppliers self-certify their parts to meet the appropriate level of AEC-Q100. There are 5 temperature categories that an IC may be qualified under.
AEC-100 automotive qualification grades for integrated circuits
The connected car eco-system
The vehicle industry is in a state of significant flux at the moment, vehicles have perhaps changed more in the last 15 years than the previous 80 years or so since mass production began. Connected cars have been around for a number of years connecting to our smartphones, delivering traffic alerts and towards the higher end even relaying diagnostics to manufacturer’s service centers. The move to electric driven vehicles is significant, as is the imminent approach of the self-driving car. A series of industry progressions have been identified and formalized Vehicle to Passenger (V2P), Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I), collectively known as V2X. All 3 V2X elements are already in progress and are in various levels of implementation.
It is V2P however that looks set to climb the steepest in the next 5 years, as the technical challenges and sheer scope of the task is perhaps somewhat simpler than with V2V and V2I. The technology to do it is in place, Bluetooth low energy, the industry knowledge is in place as Bluetooth low energy is now a mature technology after 5 years of runaway success, and with devices such as the nRF51824, the building blocks of low cost, high performance, Bluetooth low energy SoCs are also now available at automotive grade.
Irrespective of the overall pace of progress of cars being wedded to infrastructure and to each other the connectivity developments both within and external are moving forward at a very fast pace. Vehicle telematics are here already with built in GPS and cellular connectivity. Additional to this is the car as a connected eco-system, the car as its own personal area network that wraps around the driver, their needs, and the driving experience. Bluetooth is such a well suited technology for this scenario, short range, low power and ubiquitous in mobile devices such as smartphones and tablets. There is plenty of scope for migrating certain non-critical applications to operation over Bluetooth low energy to reduce the dependency on cable looming and associated benefits of easier assembly and maintenance or replacement as units can become much more modular and self-contained.
There are predictions of sensor ‘swarms’ within vehicles using Bluetooth low energy in the next few years that will do everything from already existing functions such as Remote Keyless Entry (RKE) and Tire Pressure Sensors (TMS) to a network of sensors and actuators around the interior, and exterior of the vehicle to act as telemetry links for mirrors, cameras, occupant bio-med, collision avoidance and impact assessment and alarm to mention but a few. Typically, these sensor eco-systems will communicate to our personal mobile devices and to in-car communication hubs. Where necessary important sensor date and critical events can then be relayed to and from the network at large via cellular connections. Much in the vehicle industry is in a state of rapid evolution and not all is known at this stage, that vehicles themselves will be a buzz of sensor communication activity in their own right is already assured
In-car wireless charging solutions from Nordic
In car wireless charging is one very attractive option for automotive manufacturers and after sales product specialists. For so long now the old cigarette lighter socket has continued to exist in vehicles, no longer for its original purpose but purely as a means to source electrical power for the operation and charging of other things, most typically our phones. Wireless charging seeks to make charging simpler, it would also render the extra cost of the cigarette lighter slot, or USB ports unnecessary, so a clear incentive for adoption.
A number of wireless charging standards currently are in play, each with their pros and cons. The Airfuel Alliance came out of the Alliance for Wireless Power (A4WP) and is an alliance that promotes resonant field wireless charging. It is standout in it's suitability to everyday use and how we live our lives with mobile devices. A particularly attractive aspect of resonant wireless charging is that it offers degrees of spatial freedom in regards to placement of devices requiring charge onto charging surfaces. Airfuel technology does not require exact placement and alignment, it really is a ‘drop and charge’ solution. Charging can occur anywhere on the charging surface and charging will take place even when devices under charge are placed on top of other objects, magazines, pens, shopping lists, books, even wooden and metallic objects. Real-world wireless charging.
The Airfuel standard uses Bluetooth low energy and the communication medium for control of the charging operations. It operates at 6.83MHz and uses Bluetooth low energy for out of band communications. It supports the charging of multiple devices (up to 8) on a single surface and can intelligently detect the presence and number of devices that need charge and the level of charge required.
Nordic Semiconductor offer the nRF5 Airfuel SDK to support nRF51 (including nRF51824) and nRF52 series SoCs for Airfuel applications. This SDK supports development of both Power Receiving Units (PRU) and Power Transmitting units (PTU), which could for example be a charging mat (PTU) and a wearable activity monitor (PRU). The nRF5 Airfuel SDK supports simultaneous charging of up to 8 divices.
nRF5 SDK for building your automotive applications
The nRF5 SDK is also available to support the building of your automotive applications. The SDK offers a wealth of profiles and modules and some complete application examples. On inspection of the nRF5 SDK you will find development support for Alerts, proximity, a range of health-related Bluetooth profiles and some very useful generic applications such as the UART profile for moving data around as you would normally over a wired UART connection only it handles the adaptation to transport across a Bluetooth low energy link. Over The Air Firmware Upgrade (OTA DFU) is also supported in nRF5 SDK allowing you take advantage of the flash-based architecture of nRF51 and nRF52 series SoCs. This allows for firmware to be upgraded in-situ giving you the freedom to correct code issues and introduce new features and improved functionality.
The future
The future of automotive is exciting. The first wave of connectivity will focus largely on achieving better driving, safety and driving experience levels. Beyond that vehicles look set to become productivity and entertainment zones. The range of applications is vast, but essentially similar, the collection, relay and processing of information, a task the nRF51824 and its supporting software is ready for.
