TWEAKER:>
Some of my friends had modded or overclocked or done something to their PC's . I never felt any deficiency in my PC except for a shortake of RAM so had held back from doing stuff. And that mods in my domain of experstise...(sound) was harder to do..But now...>:) I can also claim to have done something... my onboard Realtek ALC650 based solution is the subject of these tweaks... the nvidia utility That is supposed to be used for nforce ' boards apparently has a few hidden options .A few registry hacks later...ta da.............
the advance settings page is nice and the audio firewall is even better giving more control of over the degree of acess each program might have over the audio device...the only problem is that the ALC 650 is just a "CODEC interface" and not a hardware accelerated sound device. so all these remain on s/w to match this...I tried runnig SRS circle surround II decoder and the soundcard utilites. The surround performance was quite adequate but IT did have a bit of distortion at top levels and cpu usage was 20%:( ...software acceleration...[ rolleseyes]..IF you wannna do it ...feel free to ask
posted by kickassso, 7:33 AM
Scope of the Device
NO Discussion would be complete without the scope of the said deviceIn this we usually discuss the future of a project. Frankly we think our project is the future. Advanced recognition techniques and sensors are being developed with better characteristics and lower costs enabling faster cheaper and more accurate detection. A project of this scale would have cost much much more a decade ago. In our case development of powerful microcontrollers as well as reliable detectors makes it better than fast attempts at the same.
A 2D array can provide significantly enhanced control ability, because of the fact that instead of two control directions. In a 2D array we can achieve 8 directions (or more). They can for example be used to select an option for which the control can be applied.
Even among the sensors SHARP offers significantly wider range with modules capable of sensing and transmitting the sensed distance. Instead of just a logic level which is a result of the comparison of the sensed distance with a preset value. An array of such sensors could achieve, in the manner mentioned previously, 3D sensing which can offer a much more powerful interface. Eg motion replicators etc.
The decoder stage ie(uC) can be reprogrammed with more optimized algorithms (if any are developed) leading to more optimized detection.
Similarly the interface with a PC can also yield better results using powerful software.
If mass produced the economies of scale can reduce the cost of this interface allowing it to be economically incorporated into a host of devices allowing for an unprecedented change in the way in which humans interact with the devices by simplifying the man machine link.
Embedding the interface into physical space enables the creation of reactive environments that can automatically respond to user’s gestures.
We have already mentioned a limited number of applications so far. Where as the actual no of possibilities are limitless. The range of application of this interface is limited only by human imagination.
posted by aravind, 9:44 PM
How to design the kinematic Intuitive control interface
Our Approach
We decided to use a linear array of proximity sensors to detect the presence of hand and its position. The so detected information was to be sent to a decoder which would determine the required control information from the input given to it. The control information could be used to interface with a variety of devices in the parallel format.
Three options were initially available to us for non contact detection.
- Ultra sonic proximity detection
- Capacitance based detection
- IR based detection.
- Camera based detection.
Ultra sonic detection was primarily ruled out because of its bulk and its slow response. Capacitance based sensors offered the most discrete sensing but were also ruled out over questions of possible interference between detectors and detection speed. Camera based detection was considered, in which the video feed from a camera would be analyzed using DSP to determine the predominant motion vectors. This would have enabled a wide range but at a very much increased cost and complexity of both the hardware and detection algorithms. Moreover possible false triggering also posed problems to similar models in development now. Thus a hardware based approach employing infra red sensors was chosen. Infra red sensors have the advantage of being invisible and having a fast response time.
This device worked well in preliminary trials, giving consistent outputs for up to two receiver transmitter pairs operated simultaneously. However a larger no of devices coupled with high sensitivity of TSOP 1738 module caused interference between the sensors leading to latching. Remedying this increased the circuit complexity to an unviable level (compromising the goal of cost effectiveness) Hence all costs taken into account a suitable replacement. Was found in later stages of development in the Sharp GP2D15 which offered detection of object based on the angle of the reflected light and thus could be used simultaneously with other devices.
LOGIC
The digital output thus obtained was to be fed to a decoder section consisting of, initially, hardwired digital logic detection based on a bank of comparators shift registers and gates. The output of which control a self stopping four bit up/down counter. But as the detection logic was optimized and made more reliable the part count increased to highly unmanageable level. At this stage a microcontroller was considered as a possible replacement.
Why 16f628?
Of the two types available the 89C51 and the 16Fxxx series the 16F series was chosen due to the simplicity of its hardware and software implementation. 18 pins (two ports) and 35 instructions it’s a much more elegant solution. However there are two mainly used 16F series ICs are 16f84, 628, and 877. The 877 has more ports (4) than required and was not considered. The 16f84 the erstwhile industry standard PIC though still highly popular was not taken and instead 628 was chosen due to the following reasons.
Thus 16f628 was chosen. Initially the detection algorithm used was a direct equivalent implementation of the hardwired logic design. This caused the decoder to have the same problems as the working hardwired prototypes. We realized that since we were working with a microcontroller a much larger range of options were available to us to decode the input as opposed to what was available with hardwired logic. This entire code was rewritten using a new algorithm.
Applications
The scope of such interface is virtually unlimited. It can be used in almost any situation where control inputs have to provided by hand. Example any panel mounted switch or other control. It can be considered as a direct replacement for a rotary potentiometer or up/down digital tapping controls. It can also be adapted to suit a host of other applications. To showcase the wide variety of application we decided to undertake a volume control as the default application. Other applications have been proposed.
Volume Control
It is a digital 16 levels x 2dB digital attenuating control working on a four bit input. Variable attenuation is achieved by selecting the inputs of a potential divider tapped at the required levels. Two multiplexers are used one operating at 8db steps (based on two MSB) and the other 2db steps (based on two LSB). The two multiplexers are buffered in between to prevent mutual loading by the two resistor network and also at the input and output. A high quality and low noise and distortion dual op-amps NE5532 are used. A led display for the volume level is also integrated to give the user a visual indication of the input volume levels. The Samsung KA2281 dual channel five level LED display driver IC is used for that purpose. Control of this is achieved using a parallel interface. There are two sets of inputs and outputs Using RCA connectors and mini stereo connectors. The mini connectors are given priority (if connection is given to both the mini and RCA connectors input from the mini connectors will be chosen).
A five volt DC output is provided for independent power for the interface.
Other Applications
The implementation of the parallel interface allows for the easy connection to a parallel port. Serial port connectivity is also provided using the inbuilt USART of the 16f628. Thus a variety of options are available to interface for the user. Thus support for all standard LEGACY connectors is provided. Support for more connection standards can be added by using the available converters.
At the PC end the four bit output will be available in the registers associated with the ports. This data can be used to control applications running in the PC. This itself provides a much larger scope for e.g. volume control of programs running in the PC as well as using the interface as a scroll tool.
Alternatively the decoding provided by the microcontroller can be bypassed and the four bit input from the sensors fed directly to the PC for more powerful processing using packages like MATLAB.
We can input binary data into this but at the cost of increased physical and mindless effort.
posted by kickassso, 3:27 AM