APPLICATION: 3D RF GAMING CONTROLLER
Sixense is offering developers a magnetic 3D wireless game controller platform that it says completely outclasses
currently popular accelerometer-based units
Oslo, Norway - December 5, 2008 - Ultra low power (ULP) RF specialist Nordic Semiconductor ASA (OSE: NOD) today announces that magnetic three-dimensional (3D) gaming and controller startup, Sixense, has selected Nordic 2.4GHz transceivers to supply the wireless links between up to four of its 3D controllers (each equipped with an nRF24L01) and a base station (nRF24LU1). The technology, called TrueMotion, was first demonstrated at the recent Nvision 08 show in San Jose in the US (see: tinyurl.com/6bzkqq for short video demonstration).
By employing Nordic ULP 2.4GHz transceivers with their class-leading price/performance ratio, the system's price point meets mass-market consumer requirements with a responsiveness that Sixense says completely outclasses currently popular, but technically limited, accelerometer-based wireless controllers. (See "Not all wireless gaming controllers are the same" below for further details.)
According to Sixense CTO Jeff Bellinghausen, the fundamental advantage of the Sixense TrueMotion system over all other motion-based wireless controllers is that it provides absolute position and orientation tracking with complete fidelity and precision down to the nearest 1mm (position) and degree (orientation).
"Instead of relying on how fast the user pushes the controller in a given direction to affect what's happening on screen, our system knows exactly where the controller is and how it's oriented at all times," explains Bellinghausen. "It reports these values 100 times per second with no shadowing or drift. And in gaming that's the difference between instructing a character to do something and actually being that character."
In operation, a small base station generates a magnetic field one fiftieth the strength of the Earth's magnetic field. The hand controllers sense changes in this field - relayed at the speed of light - and compute position and orientation relative to the base station. It is this magnetic principle that gives the TrueMotion platform its accuracy and responsiveness. Absolute position and orientation can be computed in just 6 milliseconds and, thanks to the Nordic Semiconductor 2.4GHz wireless link, are available for use by the end application only 10 milliseconds later.
For users to enjoy a truly seamless and immersive real-time experience everything hangs on the reliability of the wireless link from the controller to the gaming console or PC. Any latency or interference manifests itself as on-screen lags or stutters that can shatter the "immersive" and "connected" gaming experience. Nordic's nRF24L01 and nRF24LU1 combination offers the low-latency, high-bandwidth and excellent interference immunity that is required within the crowded 2.4GHz spectrum. (See "About nRF24L01" and "About nRF24LU1" below for further information.)
In operation, a new data packet is sent every 10ms, amounting to a 112 kBps on-air link from the controller to the base station. It is vital that at least 95 percent of all data packets get through, because lost packets will break the link between the controller and what's happening on-screen. Up to four controllers can be in play simultaneously, all frequency hopping and error checking to avoid inter-controller interference plus collisions with any other ambient 2.4GHz traffic. The data rate is 96 Kbps for four controllers (i.e. 93.75 updates per second x 32 Bytes per update x 8 bits per Byte = 24K bits per second per controller).
"We couldn't have achieved TrueMotion's level of fidelity without the underlying physical performance and reliability of the Nordic radios," concludes Bellinghausen. "Nordic allowed us to carefully fine tune our wireless software protocol in order to minimize latency and maximize performance while ensuring the critical data link performance was maintained."
"We see our patent-protected 3D wireless controller technology as the future of wireless gaming and control because it delivers a level of wireless interactivity, accuracy and responsiveness that was previously impossible at consumer price levels," explains Amir Rubin, CEO of Sixense. "The Sixense TrueMotion System has the potential to become the de facto standard in consumer 3D wireless control."
"We invest considerable resources into R&D to ensure Nordic's 2.4GHz ULP transceivers offer the best possible performance at their price point," says Geir Langeland, Nordic Semiconductor's Director of Sales & Marketing. "Sixense's selection of our transceivers for its innovative, high-spec and price-sensitive wireless gaming controller platform is further proof that we are following the right strategy."
Sixense is currently working with game publishers and developers as well as PC and console makers who wish to take advantage of its advanced and appealing TrueMotion technology.
Not all wireless gaming controllers are the same
3D wireless control is nothing new. During the last three decades many companies have attempted to use various technologies (and combinations of technologies) to produce affordable and reliable solutions. The most serious contenders have been ultrasonic, optical and inertial systems but all have fallen short due to inherent technical limitations (see Table 1: Contrasting the different types of 3D wireless controller). This has limited their gaming potential for consumers.
Although inertial systems have recently made major breakthroughs thanks to the latest MEMS accelerometer sensor technologies and have enjoyed huge popular success in the gaming market, nothing fundamentally has changed.
"Accelerometer-based wireless controllers have done a great job of introducing the concept of 3D wireless control to consumers around the world in gaming," says Bellinghausen. "But they are intrinsically limited as a technology for 3D wireless control because they rely on an inertial or "impulse" system with 3-degrees of freedom [up/down, left/right, in/out] that does not actually known where the controller is located. You can use the controller to prompt actions on screen, but little more."
As a result, accelerometer controllers have no actual spatial awareness. "A good analogy is that of sitting in a moving car with your eyes closed," explains Bellinghausen. "Although you feel the changes in the motion of the car you can't use that information to tell where you actually are located with any real accuracy. In contrast, the Sixense TrueMotion System is like having your eyes open as well."
Accelerometers also suffer from quite a high noise floor which is a direct by-product of the actual MEMS technology itself. This makes it impossible to detect slight or subtle movements and also results in extra processing overhead that ultimately increases latency and further reduces accuracy.
"In contrast, our magnetic technology knows exactly where the controller is located and how it's oriented at all times. This means the total functionality offered by accelerometers is a small subset of that offered by Sixense TrueMotion which includes both absolute X-Y-Z position and absolute pitch-roll-yaw orientation. The end result is a controller that offers a finesse and fidelity that accelerometer-based systems simply do not and cannot possess."
About the nRF24L01TM
The nRF24L01 is a unique wireless solution for compact, battery-operated applications with stringent requirements on battery lifetime and cost. The transceiver operates in the license free worldwide 2.4GHz ISM band and provides a 2 Mbps (Mega bits per second) air data rate.
Provided in a compact 4x4mm QFN package, the nRF24L01 integrates a complete 2.4GHz RF transceiver, an RF synthesizer, full baseband logic including the unique Enhanced ShockBurstTM hardware link layer, advanced power management and a high-speed SPI for the host controller interface. No external loop filters, resonators or VCO varactor diodes are required, only a low cost ±60ppm 16MHz crystal, matching circuitry and the antenna.
The nRF24L01 has a unique combination of four features that enable the implementation of ultra-low power wireless connectivity:
- A sub 13mA TX and RX active current that permits coin-cell battery operation
- An advanced power management with power saving idle mode plus rapid active mode startup
- A high 2 Mbps air data rate that minimizes the amount of time the transceiver has spend in the relatively more power consuming active on-air mode in order to achieve a given effective data rate
- An Enhanced ShockBurst" link layer that minimizes processing load on the host microcontroller reducing average current consumption
As a comparison, for a transceiver with the exact same specification, except lower air data rate, the approximate power penalty is as follows (kbps = kilo bits per second):
- 1 Mbps transceiver 2x greater power consumption
- 500 kbps transceiver 4x greater power consumption
- 250 kbps 8x greater power consumption
The nRF24L01 includes Nordic's Enhanced ShockBurstTM hardware link layer. This features both automatic packet handling and automatic packet transaction handling.
Automatic packet handling key features include:
- Packet assembly
- Packet detection and validation
- Dynamic payload length
- MultiCeiverTM support for up to 6 bi-directional logical links for 1:6 star network topologies
Automatic packet transaction handling key features include:
- Acknowledgment of received packages
- Payload in acknowledgment packet
- Retransmission of lost packages
Main benefits include:
- Ability to implement robust, high performance bi-directional and uni-directional data links
- On chip hardware implementation maximizes data throughput while minimizing on-air time saving power and improving co-existence performance
- Relaxed requirements on the host controller enables a lower cost total solution
- A lower processing load for the host controller saves power consumption for the total solution
Prime applications include wireless mouse, keyboards and joysticks, wireless headsets, intelligent sports equipment (e.g. wrist watches and associated sensors), remote control devices and Personal Area Networks (PANs).
About the nRF24LU1TM
The nRF24LU1 is a single chip solution for compact USB dongles for wireless peripherals. It provides native support for up to five bidirectional ultra-low power (ULP) wireless peripherals communicating simultaneously via a single, ultra-compact full-speed USB 2.0-compliant dongle.
The nRF24LU1 offers full interoperability with the nRF24L01TM 2 Mbps 2.4GHz transceiver and its Enhanced ShockBurstTM hardware link layer, and integrates a full-speed USB 2.0-compliant device controller, an 8051 compatible microcontroller, a hardware AES security co-processor and 16 kbytes of flash memory. The nRF24LU1 is supplied in a 5 by 5mm QFN package.
With an internal voltage regulator (covering a 4.0 to 5.25V supply range) that enables the chip to be powered directly from the USB bus, the nRF24LU1 does not require an external voltage regulator, saving cost and board space. With a fully integrated RF synthesizer and PLL for the USB no external loop filters, resonators or VCO varactor diodes are required, only a low cost ±60ppm 16MHz crystal, matching circuitry and the antenna.
The nRF24LU1 features 6 general-purpose digital input/output pins, hardware SPI slave & master (UART) and three 16-bit timers/counters. It supports firmware upgrade over USB and a FS2 hardware debugger. In addition, the nRF24LU1 is air compatible with the nRF24L01, nRF2401A, 02, E1 and E2.
The AES encryption co-processor provides industry standard data encryption and decryption at the application level, and the on-chip flash memory features fully configurable write and read back protection, offering complete protection from reverse engineering.
With air data rate of 2 Mbps combined with full speed USB, supporting up to 12 Mbps, the nRF24LU1 meets performance requirements of a wide range of applications including PC peripherals, sports accessories and game peripherals.
About Sixense (www.sixense.com)
Sixense Entertainment Inc. is a Silicon Valley company founded in 2007 with a focus on establishing its TrueMotion absolute position and orientation 3D tracking technology as the control system standard for all digital media. The videogame industry has been taken by storm in a motion gaming revolution and TrueMotion is positioned to redefine gaming by providing the ultimate motion-based experience to all gamers, hardcore and casual. Sixense's proprietary technology has been proven for decades in professional motion tracking applications in the entertainment, medical and military sectors. TrueMotion is already in the hands of leading developers and publishers, who have praised it for its ease of integration, accuracy and intuitive game play.
About Nordic Semiconductor ASA
Nordic Semiconductor is a fabless semiconductor company specializing in ultra-low power (ULP) short-range wireless communication. Nordic is a public company listed on the Norwegian stock exchange.
Nordic provides RF silicon solutions including:
- Highly integrated RF silicon
- Sophisticated and flexible development tools
- Application specific communication software
- Complete reference designs
The company's innovative range of wireless solutions includes:
- The nRF24LE1TM single-chip, ultra-low cost and power, fully integrated 2.4GHz transceiver with radio, microprocessor, flash memory and MultiCeiverTM technology supporting up to six simultaneous wireless devices;
- The nRF24L01+TM ultra-low cost and power 2.4GHz transceiver with MultiCeiver technology supporting up to six simultaneous wireless devices;
- The nRF24LU1TM a single chip 2.4GHz transceiver with full-speed USB, microcontroller and flash memory enabling ultra-compact USB dongles for wireless peripherals;
- The nRF24AP1TM ultra-low power 2.4GHz transceiver for wireless communication with Dynastream Innovation's production-proven low-power network protocol, ANTTM;
- The nRF24E1TM and nRF24E2TM low cost transceivers paired with an industry standard 8051 MCU core, and leading peripherals to create the world's first complete low cost SoCs for global 2.4GHz operation;
- The nRF24Z1TM single-chip system for CD quality audio streaming of up to 16-bit, 48-kHz audio;
- The nRF905TM single-chip multiband radio transceiver for the 433, 868 or 915MHz ISM band;
- The nRF9E5TM low-cost, single-chip system with fully integrated RF transceiver for the 433, 868 or 915MHz ISM band.
Nordic Semiconductor's nRF24xx range of 2.4GHz transceiver and transmitter devices are aimed at applications such as PC peripherals such as wireless keyboards/mice, game controllers, intelligent sports equipment and wireless audio (for example, mp3 and portable CD player headphones and PC speakers). The latest nRF24L01 family, for instance, is targeted at ultra-low cost and power applications such as wireless desktops and intelligent (for example, wristwatch-based) sports equipment.
Nordic is an associate member of the Bluetooth SIG, and has contributed core expertise in ultra-low power RF design to the forthcoming specification for Bluetooth low energy wireless technology (formerly ultra low power Bluetooth). Bluetooth low energy wireless technology is a short range RF communication technology featuring ultra-low power consumption, a lightweight protocol stack and simple integration with Bluetooth® wireless technology chips. Bluetooth low energy wireless technology ushers in the next generation of RF communications by opening up many new opportunities for wireless data links between suitably equipped mobile phones or personal computers (PCs) and coin cell battery-powered devices such as sports and health sensors.
Nordic's products are all manufactured in ultra modern semiconductor process technologies through strong relationships with world-best manufacturing facilities. Sales are primarily made through a carefully selected worldwide distribution network. The company has offices in Trondheim and Oslo, Norway, the US (west coast), Hong Kong, Korea and Japan, and is listed on the Norwegian Stock Exchange (OSX: NOD). All operations are managed according to the ISO 9001:2000-approved quality assurance system.
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