TOPAS: Applikationsnoten

Wandler+Regler+Überwachung = RICOH RP600

Fri, 27 May 2011 10:02:00 +0200

Der RP600 ist ein neues Produkt aus Ricohs Power Management IC Portfolio, bestehend aus drei elementaren Blöcken, mit denen spezielle Schaltungsanforderungen erfüllt werden können.

DC/DC-Wandler, Spannungsregler und Spannungsüberwachung sind in einem Chip vereint, basierend auf den früheren Produkten RS5RJ und RS5RM, jedoch mit erweiterter Funktionalität. siehe auch: RP600-Artikel

EXAMPLES WHEN TO USE RP600

If the input voltage varies in a range above and below the desired output voltage
A buck-boost configuration to extend battery life.
Using a single battery + boost converter instead of two batteries in series, saving boardspace / weight / cost.
Obtaining 2 supply voltages from a single source
In case the input voltage source switches between a battery and USB
In case RP400 cannot provide enough output current, suggest RP600

The duty ratio dependence is less than RP400, in some cases, RP600 can provide more than 1.5 times the output current compared to RP400.

At 1.5V input / 300mA output, the RP600 has 5% better efficiency than the RP400.

RP600KxxxA, BUCK-BOOST CIRCUIT, fixed DC/DC Converter output voltage

RP600KxxxD BUCK-BOOST CIRCUIT, adjustable DC/DC converter output voltage

RP600 INPUT VOLTAGE VERSUS THE BEHAVIOUR OF THE OUTPUT VOLTAGES.

The X-axis represents the input voltage; the operating range is from 0.8V to 5.5V and the Y-axis shows the output voltage of the DCDC converter and LDO.

In case the application requires a supply voltage of 2.8V, the LDO need to be set to 2.8V as well. The DC/DC converter output voltage needs to be set slightly higher compared to the LDO voltage, it is to have enough margin to compensate the LDO dropout voltage and to make sure that it is able to regulate well. In some cases it is convenient to select the RP600 version with an adjustable DCDC converter voltage, to have the flexibility to adjust to the best output voltage level. For this example the DCDC output voltage is set to 3.3V.

Assume that some battery is applied to the input of the DC/DC converter with a voltage of 5.5V and discharges to 0V. At 5.5V the DC/DC is turned off since the input voltage is higher compared to the voltage setting Vout1 + diode forward voltage Vf. The output of the DC/DC converter is not regulated and follows the input voltage level, the LDO regulates to the required 2.8V. As soon the input voltage decreases to a level below the voltage setting Vout1 + Vf, the DCDC converter will start up and maintains the Vout1 voltage to 3.3V. Again the LDO regulates to the required 2.8V. The DC/DC converter continues to operate until the input voltage decreases below the minimum of 0.8V, at that moment the circuit will halt. In case the circuit had no boost DCDC converter but an LDO only, it would not be able to keep the 2.8V output voltage level if the battery voltage would drop below around 2.8V.

RP600KxxxB, TWO INDIVIDUAL OUTPUT VOLTAGES FROM A SINGLE SUPPLY

Below circuit can be used if one supply voltage above and a second supply voltage below the input voltage is required. In this way two different circuits of the application can be supplied from one power source.
It is even possible to add another external LDO to the DCDC converter output in order to obtain a similar circuit as described for the Buck-Boost circuit.

RP600KxxxB, ALTERNATIVE USE

RP600KxxxC, ENERGY HARVESTING OR ENERGY SAVING CIRCUIT

It is assumed that the buffer capacitor is fully discharged when the circuit is powered up. The voltage detector measures 0V and will provide a high level at its output VDout. As a result the Boost DCDC converter will be enabled and the output voltage will ramp up. The buffer capacitor will be charged to a level equal to the threshold voltage of the voltage detector, at that moment the output of the voltage detector will change to low and the DC/DC converter will be disabled to minimize current consumption. An LDO regulator connected to the buffer capacitor regulates to a specific voltage required for the application.

As soon the DC/DC converter is disabled, the LDO is switched to ECO mode to reduce current consumption. The voltage detector has an option to select from a wide hysteresis range from 30% to 80% of –Vdet, as a result the buffer capacitor is able to discharge until the lower threshold release voltage is reached. At that moment the DCDC converter is enabled again and this process repeats depending on the discharge rate of the buffer capacitor. Such circuit can be used when powered from a solar cell for example, collecting energy in the buffer capacitor and powering a circuit with a stable voltage level as long the solar energy is bright enough. Another example is to use such circuit in a battery operated wireless smoke detector, during standby (no alarm condition) the current consumption is reduced to a minimum but also extending battery life even if the battery voltage decreases due to discharge.

...mehr über RICOH

IDT : Reference Designs

Wed, 25 May 2011 00:00:00 +0200

This collection of flyers represents IDT reference design solutions with various partners along with IDT industry leading complementary silicon for your designs. go to: IDT Reference Design Solutions

Stretch : S7000 Reference Designs

Mon, 23 May 2011 09:46:00 +0200

Stretch has developed a series of reference design kits for its powerful S7000 family of software configurable processors. Kits are available for IP camera, embedded DVR and PCIe DVR add-in card designs and include all hardware, software and source code needed to develop products using S7000 processors.

Stretch S7000 PCIe Add-in Card Reference Design Kits
Stretch S7000 IP Camera Reference Design Kits
Stretch S7000 Standalone DVR Reference Design Kits

IDT : Touching New Markets

Fri, 04 Feb 2011 12:09:00 +0100

By Alvin Wong, IDT Touchscreen technology has been one of the cornerstones in the rapid advancement in user interfaces of both portable and static electronics equipment. The iPhone perhaps represents the biggest such success story, but there are many other sectors in which product functionality, ergonomics and aesthetics have benefited by incorporating touchscreens, rather than electromechanical switches, potentiometers and the like. Resistive touchscreens have been widely adopted in mobile handsets, as well as other applications such as portable GPS and handheld gaming platforms. Despite some evolution in resistive touchscreen technology, the user 'experience' is still considered to be lacking both by product designers and, more importantly, by consumers. The magnitude of this deficiency was made clear with the arrival of projected capacitive touchscreens. Barnstorming onto the scene as the technology enabler for the intuitive user interface, projected capacitive touchscreens have become the preferred technology for smartphones and tablets. Comparing the user experience of an iPhone with a capacitive touchscreen to a resistive screen equipped smartphone is like comparing a sports car to a go kart. However, capacitive touchscreens are more expensive than resistive technology and there are significant technical challenges that need to be overcome in order to implement a new design successfully. With a limited apparent cost reduction path, an innovative change in direction is required to allow capacitive touchscreens to be considered seriously for more applications. Touchscreen technologies other than capacitive and resistive exist. These include surface acoustic wave, infrared, optical image, bending wave and active digitisation. Some of these are appropriate for niche applications and where screen sizes are very large. Others have, to a large degree, fallen by the wayside due to the competitive benefits of either resistive or capacitive approaches, particularly in portable applications. The resistive touchscreen comprises a flexible hard coated outer membrane with a conductive inner layer separated from a similar conductive layer by insulating spacer 'dots', providing an acceptable – though not high – level of performance. Because physical contact between the two conductive layers is required, point pressure – often via a stylus – is needed. Aside from this, the primary disadvantages of this low cost approach are low transmissivity of light (in the region of 75 to 85%) due to the multiple layers and limited durability of the outer polyester film layer (approximately 100,000 to 1million touches). Despite these apparent drawbacks, resistive touchscreens have been used for many years by numerous leading phone and smartphone manufacturers. Recent improvements in resistive touchscreens have focused around aesthetics, rather than function. These include a sleeker 'bezel less' design and a glossy, rather than 'filmy', appearance. However, these touchscreens still require physical pressure for a touch to be recognised, which results in a less elegant user experience.

An important plus point for resistive touchscreens comes in the supporting circuitry. With real estate at a premium inside mobile handsets, the potential to integrate previously discrete components is welcomed. In many of the latest handsets that use resistive touchscreens, it has been possible to integrate the screen controller into either the application processor, the main microcontroller or into the audio codec. This contrasts with capacitive touchscreen controllers, which typically require discrete components placed near the touchscreen to achieve optimal performance and reduce noise interference. Meanwhile, projected capacitive touch technology is well proven. Responsiveness to direct touch, rather than point pressure, a transmissivity of at least 90% and greatly enhanced screen durability due to a rigid cover lens contributed to making projected capacitance touchscreens the technology of choice for Apple. But the primary enablers for the intuitive user interface experience are the light 'pressure less' touch recognition and multitouch capability. Smooth scrolling, light flicks to pan down menus and multitouch gestures to zoom in or out are easily acquired skills for the consumer that allow rapid navigation between the iPhone's functions. Projected capacitive touchscreens traditionally consist of patterned conductive coatings (one X axis layer and one Y axis layer) aligned to produce a matrix structure. A third shield layer is often required to protect the touchscreen against the effects of the lcd or amoled display. Despite the compelling user benefits, the adoption of capacitive solutions has been relatively conservative in other market segments and there are both technical and commercial reasons for this. Firstly, today's two or three layer capacitive touchscreens are between two and five times more expensive than their resistive equivalents; for many potential users, the cost premium is too high. Another factor is there are no off the shelf solutions, so there is a significant development curve to any new implementation. This is made more challenging because a finely tuned system solution is needed – a screen and a controller cannot be simply interfaced; rather, they need to be matched carefully. The touch controller chip is typically a complex device with an analogue front end designed to reject noise and built in proprietary sensing IP and complex, custom algorithms. The final implementation issue with capacitive solutions concerns electrical robustness. To ensure noise emanating from the lcd does not impact performance, it is necessary to locate the touch controller as close as possible to the sensor; in most cases, this is on the flex tail close to the touchscreen. With traditional multilayer sensor construction, cost reduction occurs gradually with scaling and more suppliers, but not to the extent that would encourage accelerated adoption levels for existing capacitive touchscreen technology. A true single layer, multitouch indium tin oxide (ITO) solution, such as that developed recently by IDT, simplifies sensor manufacturing and has the potential to offer significant cost savings. Existing approaches require up to three conductive ITO layers: X and Y electrode layers and a third shield layer. With a typical cost of around $1 per layer for screens of up to 5in, the potential benefit of a single layer approach is easy to see. In addition, fewer layers simplify manufacturing, improve yields and improve light transmission. This reduces backlighting which, in turn, gives extends battery life. The latest addition to the IDT PureTouch family uses a proprietary one layer ITO sensor pattern that incorporates the functionality of both X and Y sensor layers. This single layer multitouch design does not require additional mask steps to insulate sensor crossover points and bridge X and Y sensor matrix lines. Additionally, by incorporating all sensors into a single layer, the IDT solution eliminates the traditional problem of multitouch ghosting, which makes accurate X/Y data determination difficult when multiple fingers are placed in ambiguous locations. With many customers using host interpreted custom gestures to differentiate their solution, accurate X/Y data from the touch controller becomes critical. Finally, the design and robustness of the touch controller ic is critical. In the case of IDT's LDS7000, the design of the analogue front end provides a high level of noise rejection performance that negates the need for a separate touchscreen shield layer. This combination of a cost effective, multitouch capable sensor and robust touch controller ic enables IDT to address this growing market in a novel way. Author Alvin Wong is general manager, AUI, with Integrated Device Technology.

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Stretch : S6000 Reference Design Kits

Mon, 20 Sep 2010 00:00:00 +0200

Stretch has reference designs for high definition and small footprint IP cameras, DVR PCIe add-in cards, and standalone DVRs. All Stretch reference designs are available as both Evaluation Reference Design Kits (EVK) and Full Reference Design Kits (RDK).

Stretch IP Camera Reference Design Kits
Stretch DVR Reference Design Kits
Stretch Standalone DVR Reference Design Kits

SynQor : A Two-Stage Approach to Highly Efficient, Super-Wide Input Voltage Range DC-DC Converters

Thu, 24 Sep 2009 11:10:00 +0200

One of the parameters of an isolated DC-DC converter is the range of the input voltage over which the converter can operate. For the industry-standard “bricks” available for the nominal 48V input telecom marketplace, this range is usually 36V to 75V, or a ratio of about 2:1 from the highest to the lowest value. But there are many applications where a converter that can handle a much wider range of input voltage variation is desirable. For instance, in some systems the distributed input voltage has significant transients and surges that last too long to be removed by a filter. As one example, Table 1 shows the steady state and transient range of the distribution voltage that might be seen in various railway systems, as specified by the various agencies listed. Military and vehicle specifications have a similarly wide range over which their distribution voltages may vary. Another reason for using a DC-DC converter that can operate over a wide input voltage range is to create a “universal” product that can be used in different DC systems. Instead of having to produce three different versions of a product to work off a nominal 36V, 48V, and 72V bus, a converter that could operate from 18V to 135V would permit a single solution, saving manufacturing costs and reducing inventory. However desirable it might be to have a wide input converter, there is a major problem: in traditional products, the wider you make the operational input voltage range, the worse you make the converter’s performance. Generally, both the converter’s efficiency and the amount of power it can handle in a given size – such as a quarter-brick- is reduced. This is the natural consequence of having to design for the highest input voltage while at the same time needing to handle the very large input current that results when the input voltage is at its lowest. For a converter that handles a 2:1 input range, the product of this maximum voltage and maximum current is twice that of the power being processed - a penalty, but one that can be accepted as a reasonable compromise. But in the case of a converter designed to handle an 8:1 input voltage range, the product is now eight times the processed power, and the penalty is extreme. This is most severely felt by the power circuitry associated with the isolation transformer of the converter.

Due to the aforementioned limitations, there are not many DC-DC converters commercially available to handle very wide range input voltages. The few “ultra-wide” 4:1 input ratio converters that are available typically process less than one half the power in a given physical size compared to their counterparts that handle only a 2:1 input voltage range. In addition, their efficiencies are typically 10%-25% lower than 2:1 units.

One way to mitigate this loss in performance in wide input range converters is to separate the converter’s “regulation” function from its “isolation” function, as shown in Fig. 1. Here, the first stage of the converter is a non-isolated “down converter” that provides regulation by varying its duty cycle. The second stage then provides electrical isolation (and typically a further step-down according to the turns-ratio of the transformer) without any further regulation. This is how SynQor – a leading pioneer in highly efficient DC-DC converters – designs all its products.

The advantage of this two-stage design is that only the first stage sees the wide range of the input voltage. While a penalty for the wide range must be paid for by this first stage, it is not so severe because the first stage does not require an isolation transformer. The isolation stage, which does have the transformer, never experiences the wide input voltage range. In this two-stage design, the input voltage - the mid-bus voltage of the two-stage approach - is always constant. This permits the isolation stage to be optimized for a single operating condition, and it makes it much easier to implement a design based on synchronous rectifiers, which greatly reduces losses. The resulting increase of efficiency in the isolation stage goes a long way toward making up for any additional losses that occur in the regulation stage. Figure 2 shows SynQor’s new IQ64 half-brick DC-DC converter with the super-wide 8:1 input range. The matrix in Table 2 shows the InQor converters and the various input voltage ranges for which they are designed. As can be seen, besides the normal 2:1 input ranges, there are products for 4:1 and even 8:1 ranges. The maximum power levels and typical efficiency for a 3.3V output version are also shown in the figure. Although there is some reduction in power and efficiency as the input voltage range widens, it is not very significant. This is the result of the two-stage approach to the power circuit design.

In addition to handling the various input voltage ranges required, the SynQor line of InQor DC-DC converters are fully encased and ruggedized to handle the harsh environments that often accompany systems that have such challenging technical requirements.

... more about SynQor

InvenSense : Wireless Motion Sensing Module (WMSM)

Tue, 10 Mar 2009 09:28:00 +0100

Wireless Motion Sensing Module (WMSM)

Wireless Motion Sensing Module (WMSM) is a simple prototype device that acquires and processes an output data from InvenSense dual axis gyroscope, process it and transmit collected information to a remote module taking an advantage of ZigBee communication protocol.

The intention of WMSM is presentation of ability of providing the motion sensing at point and time of need without limiting independence and mobility of system components. WMSM is able to communicate with any other devices that use ZigBee high level network communication protocol. ZigBee 2004 version of network stack is used to achieve bidirectional communication between prototype and remote destination device. For benchmarking the prototype functionality Jennic JN5121-EK010 Evaluation Kit (EVK) was used.

The Jennic Zigbee EVK package consists of one controller board and four sensor boards. For testing WMSM the controller board was used with specially designed software based on Wireless Sensor Network (WSN) project available on Jennic Support Web Portal. During normal operation controller board from EVK is acting as a co-ordinator and on the other side WMSM is acting as Router. Co-ordinator of the ZigBee network is responsible for receiving data from Router sent via the ether and retransmitting it to the PC via serial connection. Co-ordinator is also able to print collected data on its' LCD panel. WMSM prototype was done in order to show possibility of increasing functionality of many consumer applications. In consumer electronic market there are many applications where rate of rotation (motion) sensing is required. The following example applications can be considered in order to characterize set of demand for prototype device.

GSM car navigation systems require rate of rotation measurements for dead reckoning scenarios. This is essential in case when less than 3 satellites signal is available or very low signal strength is achievable i.e. in high multi path environments like down town locations. An ideal car navigation system should be then equipped in motion sensing module which will allow specifying the movement direction even in case of lack of GPS signal. Because in many cases GPS receivers are mounted independently from LCD panel there is also a need of wireless communication between independent system components. In that case ZigBee communication is an ideal solution. Holter ECG meters require rate of rotation measurements for fall detection situations. In many cases Holter ECGs are used in hospitals allowing the permanent monitoring without need of limiting of patients mobility. In that kind of environments network communication is used to ensure permanent connection with remote telemedicine center. MEMS gyroscopes for emergency detection and ZigBee communication are then very interesting solutions in case of remote monitoring of patients.

Remote wireless game peripherals, TV / DVR remote controllers and handheld TV displays in many cases require the measurement of rate of rotation. This is essential to translate behavior from real world to virtual world in case of remote controllers providing i.e. intensification of gaming experiences. In case of TV displays gyroscopes can be used to allow the user free positioning of display consequently ensuring great freedom for location of display.

Realization of a prototype solution needs careful examination and definition of a set for demands of the proposed system. These should be defined taking into account different aspects that are associated with such the factors as future applications, user expectations and hardware requirements. The WMSM meets the following factors.

Rate of rotation measurement is ensured using InvenSense IDG-300 Dual-Axis Gyroscope Evaluation Board. IDG-300 is an integrated X- and Y-axis angular rate gyroscope on a single chip. It is supplied with 3V voltage. Supply voltage for IDG-300 should meet strict requirements. Power supply Voltage (VDD) rise time must be less than 20ms and gyroscope should be isolated from system power supply noise usually by a combination of an RC filter and Low Drop Out power supply regulator (LDO). The output data of IDG-300 is given in form of analog voltage that is proportional to the angular rate in case when sensor is rotated about X- or Y-axis. All gyro outputs need to be converted to a digital value taking into consideration that minimum 12 bit ADC is needed for best performance. That should result in 0.7mV/bit resolution for 3V supply which is fine in case of 2VmV/ º/s IDG-300's sensitivity.

Analogue data conversion, its processing and wireless transmission to a remote destination is ensured taking an advantage of Jennic JN5121 wireless module enabling developer to implement IEEE802.15.4 or ZigBee compliant system with minimum time to market and at the lowest price. The heart of JN5121 module is JN5121 wireless microcontroller. Each JN5121 chip provides transceiver and microcontroller features with peripherals such as 4 input 12-bit ADC, two 11-bit DACs, temperature sensor, two timer/counters, two 2 UARTs, SPI Port, 2 wire serial interface and GPIOs. The Integrated Peripheral API defines functions that allow simple use of these peripherals without need of accessing registers by the software developer. Jennic J5121 operates with supply voltage equal 2.7V to 3.6V. There are no special external components requirements for JN5121 module what significantly improve simplicity of any prototype design.

Power supply for JN5121 and IDG-300 is ensured using low noise LDO regulator. The Ricoh RP102 voltage regulator guarantee high 3.0V output voltage accuracy, extremely low supply current (50µA) and great ripple rejection (80dB at f=1kHz). These parameters makes RP102 very suitable for the power supply for any battery-powered hand-held equipment like proposed prototype solution. Thanks to low dropout voltage and very good line and load transient response single RP102 IC is an ideal solution to power both components - IDG300 and JN5121. Usage of components form InvenSense, Jennic and Ricoh make the prototype device very simple and cost effective. These elements guarantee developers great functionality connected with simplicity of any prototype and time efficiency of design.

Copyright
Reproduction of this material without written permission of Scantec GmbH is strictly prohibited.

Disclaimer
Scantec GmbH makes no warranty about the suitability or accuracy of the information contained in this document. All the information presented in this document is only for general information purposes.

Trademarks
ZigBee is a trademark of the ZigBee Alliance. Quelle Scantec GmbH - www.scantec.de

...more about InvenSense

Jennic : How to build a remote control using Jennic

Tue, 10 Mar 2009 09:26:00 +0100

1. Introduction

This document describes the concept of using Jennic wireless microcontrollers for remote controls applications. Most common remote adaptations as well as nowadays trends for remote controls have been described. The document contains also fundamental benefits of using Jennic solutions compared to traditional RF according to remote controls technology.

To get a fundamental understanding of IEEE 802.15.4 and Zigbee which are basis for Jennic technology please refer to "JN5121-EK010 - Getting Started".

2. Remotes
2.1 Applications

Remote controllers are used in many everyday situations serving their users specialized functionalities. Remotes are not used only for TV sets or audio systems. Remotes are used also in industry i.e. to allow control the machinery working in dangerous environments, for PCs to allow the users control almost every function of their personal computer, in hospitals and hotels to control television and also air conditioning systems, for changing the track points followed by trams and in many other situations.

2.2 Technology

Traditional remote controls are using infrared technology (IR). Each remote is equipped with light emitting diode (LED) emitting 940 nm wavelength beam of light that reaches the destination device. The simplest one button remote can be used to trigger a function of device using carrier signal however present-day multi function remotes use frequency modulating of carrier for command coding. The most popular standard protocol for infrared communication is RC5 developed by Philips.

2.3 Trends

During past months consumer electronics market has shown increasing interest in changing Infrared (IR) technology for Radio Frequency (RF) communication. It is promoted by a number of benefits of using RF comparing with traditional IR. The most intuitive one is lack of limitation for line of sight operation for the remote, because the control doesn't have to point directly at the destination device. What is more using RF technology we can control equipment in other rooms or behind cupboard doors. The second benefit is bidirectional connection that allows interactive communication with any equipment that is controlled by the user. This new functionality makes sense for using inter alia LCD displays on the remote that can be used to display the status of the controlled device or advanced browsing of menus, allowing, for example, to display the song playlist and choosing the favorite one when playing music in the room not equipped with an audio system but only a set of loudspeakers. That exciting functionality can be used also to display program guide information on the remote without interference with main TV viewing, or control multi room devices consisting, for example, of media server in one room and TV in the second one. Using RF creates also great potential for networking devices together i.e. in home theater systems expanded with intelligent building managing functionality.

3. RF technology

Considering RF wireless communication for remote controllers there is a set of different solutions that can be chosen. The most common are ZigBee, Bluetooth and its low-power extension called Wibree, Wi-Fi and a number of proprietary solutions. Considering Wi-Fi that is developed generally for network connectivity with key applications such as TVs, DVD players or digital cameras, power consumption is a concern compared with Zigbee or Bluetooth. On the other hand, Bluetooth's weakness of secure communication which is based on weak (1) E22 algorithm and E0 cipher, makes it useless for any advanced LCD equipped remotes interoperating with set-top boxes where in most cases transmitted data has to meet strict requirements for protection of content and access. It comes out that only Jennic wireless microcontrollers incorporates low price, very low power consumption, secure networking (AES 128 encryption) with large and small-scale networking stack within one device, integrating 32-bit RISC processor and 2.4 GHz IEEE802.15.4 transceiver. Jennic IEEE802.15.4 guarantees optimal solution with a lowest price with prospect of interoperability (integration with home control networks using ZigBee) and coexistence with other wireless networks like i.e. Wi-Fi. To take a brief comparison between different RF technologies please refer to the table presented below.

4. Conception of using Jennic for remote controls

The heart of the remote control will be Jennic JN5139 wireless microcontroller enabling developer to implement IEEE802.15.4 or ZigBee compliant system with minimum time to market and the lowest price. Each Jennic wireless microcontroller is comprehensive System-on-a-Chip (SoC) solution which provides IEEE802.15.4 transceiver and 32-bit RISC microcontroller features. The transceiver of each IC is equipped with MAC accelerator with packet formatting, CRCs, address check, auto-acknowledgements, timers and 128-bit AES security processor. The 32-bit RISC processor sustains 32 MIPs with low power offering additional features with peripherals such as 4 input 12-bit ADC, two 11-bit DACs, temperature sensor, two timer/counters, two UARTs, SPI Port, 2 wire serial interface and GPIOs. The microcontroller is equipped also with 192kB of ROM which stores system code, including protocol stack, 96kB of RAM for system data and optionally boot-loaded program code and 48-byte OTP eFuse storing MAC ID on-chip. The Integrated Peripheral API defines functions that allow simple use of all presented peripherals without need of accessing registers by the software developer. Jennic JN5139 operates with supply voltage equal 2.2V to 3.6V. Very low current consumption (200nA in deep sleep mode, 1.3µA sleep current with active sleep timer and 34mA when transmitting or receiving data) enables Jennic chip to use less than 1/50th power of IR to send packets. There are no special external components requirements for JN5139 module what significantly improve simplicity of any prototype design. The only requirements should be JN5139 chip, Flash memory, Crystal, PCB with printed antenna, keyboard and passives. A low price single ended PCB antenna module reference design (JN-RD-6005) with full schematics and Gerber files is available on Jennic support web portal for free even without need of registration. This reference design is an ideal starting point for any low-cost remote control application as well as functionality extension for vide variety of high-end products. The following schematic presents fully functional circuit of the JN-RD-6005 module which can be easily expanded with keyboard functionality through the use of up to 21 GPIOs.

(1) http://www.terminodes.org/micsPublicationsDetail.php?pubno=1216 http://www.cl.cam.ac.uk/research/dtg/~fw242/publications/2005-WongStaClu-bluetooth.pdf

Copyright
Reproduction of this material without written permission of Scantec GmbH is strictly prohibited.

Disclaimer
Scantec GmbH makes no warranty about the suitability or accuracy of the information contained in this document. All the information presented in this document is only for general information purposes.

Trademarks
ZigBee is a trademark of the ZigBee Alliance. Quelle
Scantec GmbH - www.scantec.de

...more about Jennic

Jennic : JN5121-EK010 – Getting Started

Tue, 10 Mar 2009 09:25:00 +0100

1. Introduction

This document describes the basics of working with JN5121-EK010 – ZigBee Evaluation Kit. More particularly “JN5121-EK010 – Getting Started” Application Note introduces the system functionality, preinstalled software and the most important concepts for user’s application development. IEEE 802.15.4 and Zigbee basics are included to provide fundamental understanding of the system which is an object of the further development. 1.1 Hardware contents

JN5121-EK010 ZigBee Evaluation Kit is shipped as fully functional system allowing the users to build ZigBee sensor networks. The package consists of one controller board and four sensor boards. Each board is equipped with an integrated antenna solution and a number of sensors that are responsible for measuring temperature, humidity and light levels. The controller board which features the LCD panel and external powering system input is prepared to take permanent responsibility for coordination of the wireless network and thus it will be normally used as Co-ordinator – the network coordination device in terminology of the ZigBee specification. The sensor boards normally will act in the network as Routers which are responsible for routing messages between End Devices that participate in the ZigBee network but are neither Zigbee Router and Co-ordinator. Using Co-ordinator and a number of Routers (and optionally End Devices) it is possible to build fully functional ZigBee mesh network. It is the network in which data are routed between nodes through continuous connections which can be automatically reconfigured to bypass blocked paths by sending data form node to node till the destination is reached. The package additionally includes two serial converters necessary to convert RS232 voltage level to LVTTL level and one serial cable equipped with male and female DE-9 connector.

1.2 Software contents

Software for JN5121-EK010 in most cases should be downloaded from Jennic’s support web portal (http://www.jennic.com/support/index.php) because of continuous evolution. The only exception could be a CD (optionally supplied by vendor) containing a trial version of Sensor Network Analyzer tool developed by Daintree Networks. Usually users will be interested in downloading Software Development Kit (SDK) that will allow creating firmware with use of appropriate Application Programming Interface (API). On Jennic’s support web portal it is possible to find and download (even without registration) Integrated Development Environment (including SDK) based on Code::Blocks platforrm. Apart from software development tools, Jennic offers also free of charge, sample applications, presenting the proper use of APIs. These are fully functional applications that can be built under toolchain and programmed directly into the FLASH memory of the wireless module. JN5121-EK010 ZigBee Evaluation Kit is shipped with installed firmware stored in Flash Memory. Preinstalled firmware allows the user to realize ZigBee home sensor network. The demonstration application is provided to give an example of software that is built on the top of ZigBee stack. In this example application, controller board is used as Co-ordinator and sensor boards are functioning as Routers and End Devices. Routers and End Devices measure temperature, humidity and light level and send this data periodically to the Coordinator which displays received measurements on the LCD panel.

1.3 Development System

Users that are working with JN5121-EK010 must provide development system. Development system should consist of PC with Windows XP OS equipped with serial communication port. A serial port is necessary to obtain connection with the serial converter which is needed for writing the user’s firmware into the FLASH memory. Serial converter can be also used to provide serial communication between EVK board and terminal application in case of simulating the UART communication between EVK board (with appropriate firmware) and other microprocessor solution. It is possible to use simple terminal application like Terminal (http://www.hw-server.com/software/termv19b.html) for that purpose. The SDK which should be installed on the development system is equipped with GUI Flash Programmer which with the conjunction with serial converter will allow changing the content of FLASH memory.

2. IEEE 802.15.4

IEEE 802.15.4 refers to the IEEE standard specifying low data rate Wireless Personal Area Network (WPAN). The standard specifies two layers – Physical (PHY) and Medium Access Control (MAC). Standard ensures the wireless transmission with low data rate (250kbps) operating in the industrial, scientific and medical (ISM) radio bands. Although the standard details three different PHY layers (868MHz, 915MHz and 2450MHz band), 2.4GHz is the only band supported by Jennic’s products.

2.1 Jen-NET and ZigBee

Jen-NET and Zigbee are the names of high level network communication protocols for digital radios based on IEEE 802.15.4 standard. These protocols are designed for defining and managing general purpose networks for embedded applications which require low data rate and low power consumption. Jennic has developed Jen-NET and Zigbee 2004 protocol stacks. Jen-NET is Jennic’s 802.15.4 based stack supporting point to point, star and tree networks. Jennic Zigbee2004 (ZigBee Compliant Platform) is intended for mesh networks. These are the networks in which data are routed between nodes through continuous connections that can be automatically reconfigured to bypass blocked paths by sending data form node to node till the destination is reached. Although ZigBee 2004 stack can be considered as more or less obsolete at the moment, it is sufficient for most applications supporting up to 250 nodes. Jennic ZigBee 2007Pro stack should release on the fourth quarter of 2007. It is quite important to note that it won’t be interoperable with ZigBee2004 Stack.

3. ZigBee applications development

A typical embedded application intended to work in WPAN usually contains the implementation of user defined tasks (like sensor data acquisition and processing for nodes) and implementation of network protocol stack. In case when more than one task will need to use microcontroller resources at the same time it is essential to provide the task scheduler. To ensure sharing the control over microcontroller between user specific functions and protocol stack, Basic Operating System (BOS) was developed by Jennic. Therefore each ZigBee developer is responsible for starting ZigBee stack and BOS with use of appropriate API functions and later on running system specific functions. All APIs required for initializing and management of Zigbee stack and BOS are provided as part of Jennic's Software Developer Kit (SDK).

3.1 Application Programming Interfaces

Development of firmware designed for ZigBee network nodes can be easily achieved thanks to the following APIs. For more detailed information about Application Programming Interfaces please refer to the API documentation available on the Jennis’s support web portal.

Application Development API

The functions defined in Application Development API are responsible for providing the means for interaction between user application and ZigBee stack software which is transparent for the developer. More particular Application Development API is responsible for ZigBee stack initialization for each ZigBee node (Co-ordinator, Router or End Device). This API defines the main entry points from boot loader. Each developer must define the following functions: PUBLIC void AppColdStart(void) and PUBLIC void AppWarmStart(void) in order to initialize ZigBee device. Below is presented the basic example of ZigBee node initialization.
PUBLIC void AppColdStart(void) {

/* Set up for network information */
JZS_sConfig.u32Channel = WSN_CHANNEL;
JZS_sConfig.u16PanId = WSN_PAN_ID;

/* General initialization */
vInit();
}
PUBLIC void AppWarmStart(void)
{
AppColdStart();
}

Application Framework API

The Application Framework API defines functions and data structures allowing the user to interact with the application framework which can be simply defined as a standard structure of application for Jennic ZigBee applications. This API is responsible for management of data frames and device descriptors.

ZigBee Device Profile API

ZigBee Device Profile API interacts with the remote ZigBee node Application Layer. It is used in order to identify other devices (Co-ordinator, Router or End Device) and to achieve the access to the services provided by them.

Basic Operating System API

Basic Operating System API is used to perform task management (i.e. through registering the task with the BOS), handling the messages and events (sent between application and BOS), memory management (i.e. for dynamic memory allocation), interrupts handling (i.e. enabling interrupts) and error handling. As already mentioned in the introduction section of this paragraph, software developer is responsible for starting ZigBee stack and BOS. Initialization takes place in PUBLIC void AppColdStart(void) and/or PUBLIC void AppWarmStart(void) functions as follows:
PRIVATE void vInit(void)
{
/* Initialize Zigbee stack */
JZS_u32InitSystem(TRUE);

/* Initialize serial interface*/
vUART_Init();

/* Start BOS */
(void)bBosRun(TRUE);
}

Integrated Peripherals API

Each JN5121 or JN5139 chip provides transceiver and microcontroller features. Microcontroller can be characterized as 32-bit RISC equipped with the number of peripherals such as 4 input 12-bit ADC, two 11-bit DACs, temperature sensor, two timer/counters, two 2 UARTs, SPI Port, 2 wire serial interface and GPIOs. The Integrated Peripheral API defines functions that allow using these peripherals without need of accessing registers by the software developer.

AES Coprocessor API

Wireless transceiver of either JN5121 or JN5139 is equipped with security coprocessor (128-bit AES). The AES Coprocessor API defines functions that allow using security engine without need of accessing registers by the software developer.

Board API

Board API provides the means for interacting with the Jennic's evaluation board components allowing the user to interact with LEDs, LCD panel and temperature, humidity or light sensors through using simple functions instead of directly accessing the registers.

3.2 Sample application development

In order to test the functionality of JN5121-EK010, the Wireless Sensor Network (WSN) sample application was used and modified. The original version of WSN application can be downloaded from Jennic’s support web portal. WSN application is an implementation of Co-ordinator and Router nodes software based on Jennic's Zigbee stack. The Co-ordinator is responsible for receiving data from nodes via the ether and retransmitting it to the PC via serial connection. This application can be easily modified to achieve quasi AT commands interface available through UART. That kind of interface could significantly improve the complexity of the system allowing use of simple communication interface with a separate MCU (for example). AT commands communication could be used for starting and configuring the network. At the moment serial AT-type command set is not available for Jennic's products. It is quite relevant to notice that AT-Jenie solution should release on the fourth quarter of 2007.

3.3 Main application functions

After switching on the board the AppColdStart function is run as a boot loader entry point. This function is intended for system initialization and it is possible to call in this function user defined initialization procedures like i.e. starting up the UART or LED control system. Usually the most important ZigBee system parameters are set in this function. In the example of system initialization presented in 3.1 paragraph radio channel and PAN ID were set. That is also the place to initialize Zigbee stack and finally start BOS. After starting Basic Operating System JZA_vAppDefineTasks function is called by the BOS in order to allow the application to initialize (register within BOS) any tasks that it requires. In next step after running some internal and transparent for the user procedures JZA_boAppStart function is called by the BOS. It is the function which is responsible for setting up the profile information and starting up the network activity. In this function Zigbee Stack must be started within JZS_vStartStack before returning to the BOS. After starting up the ZigBee protocol stack, BOS is always calling one of the following functions: JZA_vAppEventHandler, JZA_vStackEvent, JZA_bAfKvpObject, JZA_vPeripheralEvent, JZA_bAfMsgObject, JZA_vAfKvpResponse, JZA_vZdpResponse allowing the user to get control from the level of user's application. To find detailed information about the functions listed above please refer to the ZigBee Stack User Guide available on the Jennic's support web portal. The flow diagram of a generic application is also available in this document.

3.4 Building project

In order to build the WSN application user must ensure that project files are located in separate folder under the following directory:

C:JenniccygwinjennicSDKApplication

The project files are available for each chip model (JN5121 or JN5139) and device type (Co-ordinator and Router). In case of JN5121-EK010 Evaluation Kit that will be:

JN5121_WSN_Coordinator.cbp
JN5121_WSN_Router.cbp

Building software for selected node type (under Code::Blocks IDE) should be started from opening the appropriate project file (i.e. JN5121_WSN_Coordinator.cbp). Then the user can modify the code and compile it using Build command from Build menu. After completing that process, the build log is available for the user in the bottom side of the IDE window. After compiling the project files intended for each node type, binary files (JN5121_WSN_Coordinator.bin and JN5121_WSN_Router.bin) will be available under the following directory:

C:JenniccygwinjennicSDKApplicationJN-AP-1015-Zigbee-Wirele
ss-Sensor-NetworkJN5121_BuildRelease

The most convenient way to download the .bin files into the FLASH memory is to use the GUI Flash Programmer application available under Tools menu of the Code::Blocks IDE. It is an intuitive tool that should be used with the conjunction with serial converter connected to the intended board. It is quite important to note that Flash Programmer after starting up will automatically set RTS line for default COM port. In case when user will change serial port than it is necessary to use Refresh command and reset the JN5121 board in order to set it into the programming mode.

Copyright
Reproduction of this material without written permission of Scantec GmbH is strictly prohibited.

Disclaimer
Scantec GmbH makes no warranty about the suitability or accuracy of the information contained in this document. All the information presented in this document is only for general information purposes.

Trademarks
ZigBee is a trademark of the ZigBee Alliance. Quelle
Scantec GmbH - www.scantec.de

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