To solve one of the problems, I needed to programmatically obtain and process images of a small area of the paper surface from a very close distance. Having not received decent quality using a regular USB camera and already halfway to the store for an electron microscope, I remembered one of the lectures in which we were told how various devices, including a computer mouse, work.
Preparation and a little theory
I will not go into details of the operating principle of a modern optical mouse; it has been written about in great detail (I recommend reading it for general development).After googling information on this topic and disassembling an old PS/2 Logitech mouse, I saw a picture familiar from articles on the Internet.
Not a very complicated design of “first generation mice”, an optical sensor in the center and a PS/2 interface chip slightly higher. The optical sensor I came across is an analogue of the “popular” models ADNS2610/ADNS2620/PAN3101. I think they and their counterparts were mass produced in the same Chinese factory, with different labels on the output. Documentation for it was found very easily, even with various examples code.
The documentation says that this sensor receives an image of a surface measuring 18x18 pixels (400cpi resolution) up to 1500 times per second, stores it and, using image comparison algorithms, calculates the offset in X and Y coordinates relative to the previous position.
Implementation
To “communicate with the sensor” I used the popular computing platform Arduino, and decided to solder directly to the legs of the chip.
We connect 5V and GND to the corresponding Arduino outputs, and the sensor legs SDIO and SCLK to digital pins 8 and 9.
To obtain an offset by coordinates, you need to read the value of the chip register at addresses 0x02 (X) and 0x03 (Y), and to dump the picture you need to first write the value 0x2A at address 0x08, and then read it from there 18x18 times. This will be the last “remembered” value of the image brightness matrix from the optical sensor.
You can see how I implemented this on Arduino here: http://pastebin.com/YpRGbzAS (only ~100 lines of code).
And to receive and display the image, a program was written in Processing.
Result
After a little “finishing” of the program for my project, I was able to receive an image directly from the optical sensor and perform all the necessary calculations on it.
You can notice the texture of the surface (paper) and even individual letters on it. It should be noted that such clear picture quality is obtained due to the fact that the developers of this mouse model added a special glass stand to the design with a small lens directly under the sensor.
If you start to lift the mouse above the surface even a couple of millimeters, the clarity immediately disappears.
If you suddenly want to repeat this at home, to find a mouse with a similar sensor, I recommend looking for old devices with a PS/2 interface.
Conclusion
Although the resulting image is not very large, it was quite enough to solve my problem (barcode scanner). It turned out to be very economical and fast (a mouse for ~100 rubles + Arduino + a couple of days to write the code).I will leave links to materials that were very useful to me for solving this problem. It really wasn’t difficult and was done with great pleasure. Now I'm looking for information about the chips of more expensive models of modern mice to obtain high-quality images with higher resolution. I might even be able to build something like a microscope (the image quality from the current sensor is clearly not suitable for this). Thank you for your attention!
Gaming devices are devices with special characteristics. A gaming mouse should be comfortable when playing, with support for the hand, symmetrical (for right-handed and left-handed people), inexpensive, preferably not wireless, but connected directly to the computer. The sensitivity of the laser or optical sensor is the main characteristic; the smoothness of movement and response speed depend on it.
What is a gaming mouse
With the development of technology, the sale of manipulators for gamers began. Gaming mice for PCs are highly ergonomic. They have hot buttons programmed for given commands. For shooters, gaming mice are equipped with soft scrolling and excellent sensor accuracy to quickly switch between types of weapons, shoot clearly, without jerks or accidental misses.
Rating
Manufacturers regularly develop new products, improving specifications, improving the interface. The best gaming mice are produced by the following brands:
- Razer – specializes in gaming peripherals;
- Logitech – offers models in different price segments;
- A4-Tech is a Chinese manufacturer whose main products are gaming mice for computers;
- SteelSeries is a Danish company that develops gaming controllers;
- Mad Catz is a company that offers universal devices with complex designs.
The best gaming mice
The presence of a manipulator that is ergonomic and functional is mandatory when using not only a desktop computer, but also a laptop. Gamers use the mouse to control their characters in shooters, RPGs, and strategies. In sports simulators, it is more convenient to work with it in the menu, although it is not used in cyberspace.
Professional gaming mice
Premium gaming computer devices are expensive. Choose them correctly based on reviews with photos, promotions, sales and discounts, with free shipping by mail, which will slightly reduce costs:
- name: Razer DeathAdder Chroma;
- price: 6,500 rubles;
- characteristics: warranty - 2 years, declared service life - 4 years, resolution - 10,000 dpi, frequency - 1,000 Hz, response - 1 ms;
- pros: cord length – 2.1 m;
- Cons: high cost, few keys.
Those who want to have a beautiful, functional and durable manipulator should pay attention to this model:
- name: Thermaltake Tt eSPORTS;
- price: 4,000 rubles;
- characteristics: relatively large dimensions - 121x69x41 mm, AVAGO 9500 laser sensor;
- pros: up to 5,700 dpi – resolution, frequency – up to 1,000 Hz, each button is designed for 5 million clicks;
- cons: simple external design.
Laser
Due to the higher sensitivity of the sensor, mice in this category are considered better than optical models:
- name: Mad Catz M.M.O.TE Gaming Mouse;
- price: 7,000 rubles;
- characteristics: LED indicators of mode and resolution, protection against wire kinks, laser sensor with a resolution of up to 8,200 dpi, 20 buttons;
- pros: customizable individual characteristics user;
- cons: not found.
The best gaming mice for personal computers in this segment include:
- name: G. Skill Ripjaws MX780;
- price: up to 6,000 rubles;
- characteristics: on-board memory, 8 buttons;
- pros: adjustable in weight and height;
- cons: keys under thumb can quickly fail.
Optical
When choosing between a laser and LED gaming mouse, you should understand that the first one is more expensive, but is highly sensitive:
- name: DEFENDER Safari MM-675;
- price: 500 rubles;
- characteristics: wireless, 6 keys, sensor resolution 1600 dpi;
- pros: affordable price with good functionality;
- Cons: Suitable for right-handed people only.
The quality of the sensor determines the smoothness of the cursor movement. For large monitors Models with sensitivity from 1000 dpi are recommended:
- name: RAZER Naga 2014;
- price: 3200 rubles;
- characteristics: wired, 19 keys, stylish case;
- pros: high sensor resolution – 8200 dpi, ideal for games;
- cons: not the lowest cost.
Wireless
These USB manipulators are easy to move around the work surface:
- name: A4Tech Bloody Warrior RT7;
- price: 2,200 rubles;
- characteristics: 20 million clicks, sensitivity up to 4,000 dpi;
- pros: microUSB charging;
- cons: for some, the small number of customizable buttons and small battery capacity will be unacceptable.
Such devices exhibit a slight slowdown in response compared to the wired model. This wireless gaming mouse is comfortable and functional:
- name: Logitech G900 Chaos Spectrum;
- price: 10,000 rubles;
- characteristics: sensor sensitivity – 12,000 dpi, symmetry – suitable for left-handers;
- pros: charging via a cable with a rigid fixation, high-quality material;
- cons: high price.
Backlit
The gaming mouse differs from the office version in its bright design:
- name: Zelotes 5500 DPI;
- price: up to 30 dollars;
- characteristics: protrusions on the sides for fixing the brush, illuminated scroll wheel, side panels different colors;
- pros: additional buttons minimize the use of the keyboard, the manipulator supports Microsoft and Mac OS;
- cons: none.
In addition to the unusual shape, patterns, appearance complemented by lighting. Another notable model in this category:
- name: Qcyber Tur 2 GM-104:
- price: you can buy a gaming mouse for 2,600 rubles;
- characteristics: 10 buttons;
- pluses: selection and adjustment of the reference pad, laser sensor with a sensitivity of 5,600 dpi;
- Cons: Doesn't glide smoothly on all surfaces.
Multi-button
Such mice are no less popular among users; even their not the cheapest price does not reduce the demand for the device. For example, this model:
- name: SteelSeris Rival 500;
- price: 6,000 rubles;
- characteristics: sensitivity – up to 16,000 dpi, 14 programmable keys, proprietary software;
- pros: comfortable ergonomics;
- cons: no on-board memory.
- name: Razer Naga Hex V2;
- price: 6,000 rubles;
- characteristics: 7-button thumb panel, 16,000 dpi laser sensor;
- pros: customizable backlight;
- Cons: You need to get used to using the button wheel.
Cheap gaming mouse
Budget versions of gaming devices - models for everyday use office programs, nose hypersensitivity motion sensor.
- name: Corsair Harpoo;
- price: up to 3,000 rubles;
- characteristics: 6 programmable keys;
- pros: the average size, optimal for most gamers, customizable backlight;
- cons: none.
Among the TOP manipulators that the online store in St. Petersburg and Moscow offers to order cheaply is this model:
- name: Logitech G102 Prodigy Gaming Mouse;
- price: up to 3,000 rubles;
- characteristics: sensor sensitivity – up to 6,000 dpi, medium size, weight;
- pros: the settings are programmed in the mouse itself, they do not disappear when connected to another PC;
- cons: loud buttons.
How to choose a gaming mouse
An important selection criterion is ergonomics. Models available on the market different sizes, forms. This is explained by the fact that the age of the average gamer changes every year. Half of the users completely grasp the manipulator. The second one uses a “claw” grip. Try holding the mouse different ways, it is important that the brush does not start to hurt after a while. Pay attention to the symmetry of the model and the presence of removable side panels.
Video
Is a laser or optical mouse better? This question must have worried a lot of people. The operation of an optical mouse is based on LEDs. With their help, the device is able to receive information. After this, it is processed. The built-in processor of a personal computer is responsible for this process. Laser mice do not have any LEDs. All operation of these devices is based on the use of a semiconductor laser. Additionally, they have a special sensor installed. With its help, a personal computer is able to determine the wavelength of the glow. As a result, the exact position of the device becomes clear.
What is better - an optical mouse or a laser one? To make the right choice, you need to learn about all the advantages and disadvantages of these devices. Additionally, you should familiarize yourself with the main manufacturers that produce high-quality laser and optical mice.
Pros and cons of optical mice
The main advantage of all optical mice is their cost. On the market they will cost a person much less than laser devices. Additionally, the optical mouse can boast a small gap with the working surface. As a result, you may not need to use a mouse pad. However, optical devices may not work on some surfaces. This primarily applies to glossy and glass coatings.
You should also take into account the low accuracy of the cursor. Also, the speed indicator compared to laser mice also lags behind. Overall the sensitivity of the device is quite poor. The backlight that an optical mouse has can sometimes be distracting. At the same time, this device consumes a lot of electricity. This is especially noticeable in wireless models.
What are the features of laser mice?
Laser mice can work on any surface. The accuracy rate is quite high. At the same time, the cursor speed is fast. Overall the sensitivity of the laser mouse is good. There is no visible glow in these devices. Power consumption is quite low, even in the wireless version. Additionally, the versatility of laser mice should be highlighted. If we talk about the disadvantages, we should mention the high cost of these devices. The second disadvantage lies in the large gap with the working surface. When using a laser mouse, it is advisable to use a mouse pad.
UFT optical mice
These optical mice stand out for their interesting design. The body of most models is made of bamboo. The optical mouse is connected via a USB cable. The shape of the device is ergonomic, and you can feel it in the palm of your hand. The most popular model is UFT M5. It has two buttons without auxiliary ones. The dimensions of this model are as follows: width - 50 mm, height - 30 mm, and depth - 105 mm. The market price of this mouse is approximately 900 rubles.
What is the difference between Sven optical mice?
The Sven company produces the best optical mice of excellent quality. Many models have a resolution of up to 800 dpi. The cable length of wired devices is 1.5 m. The average weight of the device is around 0.112 kg. In general, the design of optical mice is quite simple. Sven is renowned for its high-speed technology throughout the world. However, many mice are capable of working on almost any surface.
The most popular model is the Sven RX-111. This wireless optical mouse has two buttons and a scroll wheel. It is practically silent in operation. The accuracy of the manipulations is quite high. The shape of this model is completely asymmetrical. In general, it can be described as simple and economical. Its cost on the market is only 300 rubles.
Another interesting model is the Sven CS-306. This optical mouse is very compact. The width of the device is 125 mm, height - 69 mm, depth - 44 mm. The cable of the device has a standard length of 1.5 m. The body of the model is plastic and quite durable. It should also be noted that the design of the device is good. The cost of this optical mouse is 450 rubles.
Optical model "Zalman ZM-M300"
This manufacturer is not considered particularly popular, but this model is in great demand. Basically, the Zalman ZM-M300 optical mouse is famous for its functionality. There are as many as 5 buttons for this. Additionally there is a scroll wheel. The device resolution is 2500 dpi. At the same time, the update rate is at around 4500 fps.
The cable length of this model is 1.5 m. The dimensions of this device are as follows: width - 132 mm, height - 65 mm, and depth - 42 mm. The total mass of the device is 0.078 kg. As owners of the optical mouse note, it is very comfortable due to its ergonomic shape. The wheel of this model is covered with rubber. At the same time, it has relief stripes. Overall, this model is very pleasant to use.
Laser mice from Genius
This company is known in many countries. In general, laser mice of this trademark are able to boast good sensor resolution. There are many expensive as well as economical models for home and office. Additionally, they all differ in design. Considering this, you can always choose the appropriate option. The most popular model is the Genius NS 200. It has two keys and one scroll wheel.
The sensor resolution of this device is 800-1600 dpi. The dimensions of the model are as follows: length - 126 mm, height - 80 mm, and depth - 44 mm. OS A wide variety of options are supported. The price of this model is 450 rubles. Overall, this laser mouse is more suitable for the office. A slight sensitivity will not allow you to play video games at home comfortably. Additionally, the mouse has a low cursor speed indicator.
Genius GX Gaming
The Genius GX Gaming model is considered a more advanced version. This laser optical mouse is ideal for gamers. Manufacturers equipped this model with eleven buttons. The maximum overclocking rate is 8200 dpi. In this case, three areas are illuminated. Additionally, we can note the good functionality of this laser mouse. 72 commands can be assigned to this model. The cursor response time is only 1 ms.
The weight of the laser mouse can be easily adjusted. This happens due to special metal weights that are included in the kit. There are a total of 6 plates weighing 4.5 g each. Taking this into account, this laser mouse can be easily adjusted to your type of game. The standard set of the device also includes a driver for the user interface.
Plus, manufacturers include a special case that allows you to store the metal weights of the device separately. Cable length is a little longer standard size and is 1.8 m. The dimensions of this model are as follows: width - 114 mm, height - 72 mm, depth - 44 mm. The price of the device is 4500 rubles.
Summarizing
Summing up, we can finally answer the question: “Optical mouse or laser mouse - which is better?” Considering all of the above, the second option is considered the best. For home use, laser mice are more comfortable. At the same time, there is a wide range of models, and choosing the right option is not a problem.
The Genius GX Gaming laser mouse is naturally more suitable for gamers, but the Genius NS 200 is a very good choice. In turn, optical devices are much cheaper. Of the models presented above, the company “Sven” can be noted. The Sven RX-111 mouse is quite suitable for home use. She is not particularly sensitive, but most people simply will not notice the difference.
In this article, we will look at the principles of operation of optical mouse sensors, shed light on the history of their technological development, and also debunk some myths associated with optical “rodents”.
Who invented you...
Optical mice that are familiar to us today trace their origins back to 1999, when the first copies of such manipulators from Microsoft, and after some time from other manufacturers, appeared on mass sale. Before the appearance of these mice, and for a long time after that, most of the mass-produced computer “rodents” were optomechanical (the movements of the manipulator were monitored optical system, associated with the mechanical part - two rollers responsible for tracking the movement of the mouse along the × and Y axes; these rollers, in turn, were rotated by a ball that rolled as the user moved the mouse). Although there were also purely optical mouse models that required a special mouse pad for their operation. However, such devices were not encountered often, and the very idea of developing such manipulators gradually faded away.
The “type” of mass-produced optical mice familiar to us today, based on general operating principles, was “developed” in the research laboratories of the world-famous Hewlett-Packard corporation. More precisely, in its division Agilent Technologies, which only relatively recently was completely separated into a separate company within the structure of HP Corporation. Today, Agilent Technologies, Inc. - a monopolist in the market of optical sensors for mice; no other companies develop such sensors, no matter who tells you about the exclusive technologies IntelliEye or MX Optical Engine. However, enterprising Chinese have already learned to “clone” Agilent Technologies sensors, so by buying an inexpensive optical mouse, you may well become the owner of a “left-handed” sensor.
We will find out where the visible differences in the operation of the manipulators come from a little later, but for now let us begin to consider the basic principles of the operation of optical mice, or more precisely, their movement tracking systems.
How computer mice “see”
In this section, we will study the basic principles of operation of optical motion tracking systems that are used in modern mouse-type manipulators.
So, “vision” is optical computer mouse is obtained through the following process. Using an LED and a system of lenses that focus its light, an area of the surface under the mouse is illuminated. The light reflected from this surface, in turn, is collected by another lens and hits the receiving sensor of the microcircuit - the image processor. This chip, in turn, takes pictures of the surface under the mouse at a high frequency (kHz). Moreover, the microcircuit (let's call it an optical sensor) not only takes pictures, but also processes them itself, since it contains two key parts: the Image Acquisition System (IAS) and the integrated DSP image processing processor.
Based on the analysis of a series of consecutive images (representing a square matrix of pixels of different brightness), the integrated DSP processor calculates the resulting indicators indicating the direction of mouse movement along the × and Y axes, and transmits the results of its work externally via the serial port.
If we look at the block diagram of one of the optical sensors, we will see that the chip consists of several blocks, namely:
- the main block is, of course, ImageProcessor- image processing processor (DSP) with built-in light signal receiver (IAS);
- Voltage Regulator And Power Control- voltage regulation and energy consumption control unit (power is supplied to this unit and an additional external voltage filter is connected to it);
- Oscillator- an external signal is supplied to this chip block from a master quartz oscillator, the frequency of the incoming signal is about a couple of tens of MHz;
- Led Control- this is an LED control unit that illuminates the surface under the mouse;
- Serial Port- a block that transmits data about the direction of mouse movement outside the chip.
We will look at some details of the operation of the optical sensor chip a little further, when we get to the most advanced of modern sensors, but for now we will return to the basic principles of operation of optical systems for tracking the movement of manipulators.
It should be clarified that the optical sensor chip does not transmit information about mouse movement via the Serial Port directly to the computer. The data goes to another controller chip installed in the mouse. This second “main” chip in the device is responsible for responding to mouse button presses, scroll wheel rotation, etc. This chip, among other things, directly transmits information about the direction of mouse movement to the PC, converting data coming from the optical sensor into signals transmitted via PS/2 or USB interfaces. And the computer, using the mouse driver, based on the information received through these interfaces, moves the pointer across the monitor screen.
It was precisely because of the presence of this “second” controller microcircuit, or more precisely due to the different types of such microcircuits, that the first models of optical mice differed quite noticeably from each other. If I can’t speak too badly about expensive devices from Microsoft and Logitech (although they were not at all “sinless”), then the mass of inexpensive manipulators that appeared after them did not behave quite adequately. When these mice moved on ordinary rugs, the cursors on the screen made strange somersaults, jumped almost to the floor of the Desktop, and sometimes... sometimes they even went to independent travel across the screen when the user did not touch the mouse at all. It even got to the point that the mouse could easily wake up the computer from standby mode, erroneously registering a movement when no one was actually touching the pointing device.
By the way, if you are still struggling with a similar problem, then it can be solved in one fell swoop like this: select My Computer > Properties > Hardware > Device Manager > select the installed mouse > go to its “Properties” > in the window that appears, go to the “Management” tab power supply" and uncheck the box "Allow the device to wake the computer from standby mode" (Fig. 4). After this, the mouse will no longer be able to wake up the computer from standby mode under any pretext, even if you kick it :)
So, the reason for such a striking difference in the behavior of optical mice was not at all the “bad” or “good” installed sensors, as many still think. Don't believe it, this is nothing more than a myth. Or fantasy, if you prefer :) Mice that behaved completely differently often had exactly the same optical sensor chips installed (fortunately, there were not so many models of these chips, as we will see later). However, thanks to imperfect controller chips installed in optical mice, we had the opportunity to strongly criticize the first generations of optical rodents.
However, we are somewhat distracted from the topic. Let's go back. In general, the mouse optical tracking system, in addition to the sensor chip, includes several more basic elements. The design includes a holder (Clip) in which the LED and the sensor chip itself are installed. This system of elements is mounted on a printed circuit board (PCB), between which and bottom surface mouse (Base Plate), a plastic element (Lens) is attached, containing two lenses (the purpose of which was described above).
When assembled, the optical tracking element looks like the one shown above. The operating diagram of the optics of this system is presented below.
The optimal distance from the Lens element to the reflective surface under the mouse should be in the range from 2.3 to 2.5 mm. These are the recommendations of the sensor manufacturer. Here is the first reason why optical mice don’t feel good when “crawling” on plexiglass on a table, all sorts of “translucent” rugs, etc. And you shouldn’t glue “thick” legs to optical mice when the old ones fall off or wear off. Due to excessive “elevation” above the surface, the mouse can fall into a state of stupor, when “moving” the cursor after the mouse is at rest becomes quite problematic. This is not theoretical speculation, this is personal experience :)
By the way, about the problem of durability of optical mice. I remember that some of their manufacturers claimed that, they say, “they will last forever.” Yes, the reliability of the optical tracking system is high, it cannot be compared with the optomechanical one. At the same time, in optical mice there are many purely mechanical elements that are subject to wear and tear in the same way as under the dominance of the good old “opto-mechanics”. For example, the legs of my old optical mouse were worn out and fell off, the scroll wheel broke (twice, the last time irrevocably :()), the wire in the connecting cable frayed, the housing cover peeled off the manipulator... but the optical sensor works normally, as if nothing was wrong happened. Based on this, we can safely state that rumors about the supposedly impressive durability of optical mice have not been confirmed in practice. And why, pray tell, do optical mice “live” too long? After all, new, longer ones are constantly appearing on the market perfect models created on a new element base. They are obviously more perfect and more convenient to use. Progress, you know, is a continuous thing. What it was like in the field of evolution of the optical sensors that interest us, let’s see now.
From the history of mouse vision
Development engineers at Agilent Technologies, Inc. No wonder they eat their bread. Over the past five years, this company's optical sensors have undergone significant technological improvements and their latest models have very impressive characteristics.
But let's talk about everything in order. Microcircuits became the first mass-produced optical sensors HDNS-2000(Fig. 8). These sensors had a resolution of 400 cpi (counts per inch), that is, dots (pixels) per inch, and were designed for a maximum mouse movement speed of 12 inches/s (about 30 cm/s) with an optical sensor image rate of 1500 frames in a second. Acceptable (while maintaining stable operation of the sensor) acceleration when moving the mouse “in a jerk” for the HDNS-2000 chip is no more than 0.15 g (approximately 1.5 m/s2). 
Then optical sensor chips appeared on the market ADNS-2610 And ADNS-2620. The ADNS-2620 optical sensor already supported a programmable frequency of “capturing” the surface under the mouse, with a frequency of 1500 or 2300 images/s. Each photo was taken with a resolution of 18x18 pixels. For the sensor, the maximum operating speed of movement was still limited to 12 inches per second, but the limit on permissible acceleration increased to 0.25 g, with a frequency of “photographing” the surface of 1500 frames/s. This chip (ADNS-2620) also had only 8 legs, which made it possible to significantly reduce its size compared to the ADNS-2610 chip (16 pins), which was similar in appearance to the HDNS-2000. At Agilent Technologies, Inc. set out to “minimize” their microcircuits, wanting to make them more compact, more energy-efficient, and therefore more convenient for installation in “mobile” and wireless manipulators.
The ADNS-2610 chip, although it was a “large” analogue of the 2620, was deprived of support for the “advanced” mode of 2300 pictures/s. In addition, this option required 5V power, while the ADNS-2620 chip required only 3.3V.
Coming soon chip ADNS-2051 was a much more powerful solution than the HDNS-2000 or ADNS-2610 chips, although it was also similar in appearance (packaging). This sensor already made it possible to programmably control the “resolution” of the optical sensor, changing it from 400 to 800 cpi. The chip version also allowed for adjusting the frequency of surface images, and allowed it to be changed in a very wide range: 500, 1000, 1500, 2000 or 2300 images/s. But the size of these same pictures was only 16x16 pixels. At 1500 shots/s, the maximum permissible acceleration of the mouse during a “jerk” was still 0.15 g, the maximum possible movement speed was 14 inches/s (i.e. 35.5 cm/s). This chip was designed for a supply voltage of 5 V. 
Sensor ADNS-2030 developed for wireless devices, and therefore had low power consumption, requiring only 3.3 V power. The chip also supported energy-saving functions, for example, the function of reducing energy consumption when the mouse is at rest (power conservation mode during times of no movement), switching to sleep mode, including when the mouse is connected via a USB interface, etc. The mouse, however, could not work in power-saving mode: the value “1” in the Sleep bit of one of the chip registers made the sensor “always awake,” and the default value “0” corresponded to the operating mode of the chip, when after one second, if the mouse did not move (more precisely, after receiving 1500 completely identical images of the surface), the sensor, together with the mouse, went into power saving mode. As for the other key characteristics of the sensor, they did not differ from those of the ADNS-2051: the same 16-pin body, movement speed up to 14 inches/s with a maximum acceleration of 0.15 g, programmable resolution 400 and 800 cpi, respectively, picture frequencies could be exactly the same as that of the above-considered version of the microcircuit.
These were the first optical sensors. Unfortunately, they were characterized by shortcomings. Big problem The problem that occurred when moving an optical mouse over surfaces, especially those with a repeating small pattern, was that the image processor sometimes confused individual similar areas of the monochrome image received by the sensor and incorrectly determined the direction of mouse movement.
As a result, the cursor on the screen did not move as required. The pointer on the screen even became capable of impromptu :) - unpredictable movements in any direction. In addition, it is easy to guess that if you move the mouse too quickly, the sensor could completely lose any “connection” between several subsequent images of the surface. Which gave rise to another problem: when the mouse moved too sharply, the cursor either twitched in one place, or even “supernatural” phenomena occurred, for example, with the rapid rotation of the surrounding world in toys. It was absolutely clear that for the human hand, the limitations of 12-14 inches/s on the maximum speed of mouse movement were clearly not enough. There was also no doubt that the 0.24 s (almost a quarter of a second) allocated to accelerate the mouse from 0 to 35.5 cm/s (14 inches/s - maximum speed) is a very long period of time; a person is able to move the hand much faster. And therefore, with sudden movements of the mouse in dynamic gaming applications with an optical manipulator, it can be difficult...
Agilent Technologies also understood this. The developers realized that the characteristics of the sensors needed to be radically improved. In their research, they adhered to a simple but correct axiom: the more pictures per second the sensor takes, the less likely it is that it will lose the “trace” of the mouse movement while the computer user makes sudden body movements :)
Although, as we see from the above, optical sensors have been developing, new solutions are constantly being released, but development in this area can safely be called “very gradual.” By and large, there have been no fundamental changes in the properties of the sensors. But technological progress in any field is sometimes characterized by sharp leaps. There was such a “breakthrough” in the field of creating optical sensors for mice. The advent of the ADNS-3060 optical sensor can be considered truly revolutionary!
Best of
Optical sensor ADNS-3060, in comparison with its “ancestors”, has a truly impressive set of characteristics. The use of this chip, packaged in a 20-pin package, provides optical mice with unprecedented capabilities. Acceptable maximum speed the movement of the manipulator increased to 40 inches/s (that is, almost 3 times!), i.e. reached a “signature” speed of 1 m/s. This is already very good - it is unlikely that at least one user moves the mouse at a speed exceeding this limit so often as to constantly feel discomfort from using the optical manipulator, including gaming applications. The permissible acceleration has increased, scary to say, a hundred times (!), and reached a value of 15 g (almost 150 m/s2). Now the user is given 7 hundredths of a second to accelerate the mouse from 0 to the maximum 1 m/s - I think that very few people will now be able to exceed this limitation, and even then, probably in their dreams :) The programmable speed of taking pictures of the surface with the optical sensor of the new chip model exceeds 6400 fps, i.e. "beats" the previous "record" almost three times. Moreover, the ADNS-3060 chip can itself adjust the frequency of snapshots to achieve the most optimal operating parameters, depending on the surface over which the mouse moves. The “resolution” of the optical sensor can still be 400 or 800 cpi. Let's look at the ADNS-3060 chip as an example. general principles the operation of optical sensor chips.
The general scheme for analyzing mouse movements has not changed compared to more early models- micrographs of the surface under the mouse obtained by the IAS sensor block are then processed by a DSP (processor) integrated in the same chip, which determines the direction and distance of movement of the manipulator. The DSP calculates the relative magnitudes of the × and Y coordinates relative to the mouse's home position. Then the external mouse controller chip (what it is needed for, we said earlier) reads information about the movement of the manipulator from the serial port of the optical sensor chip. Then this external controller translates the received data about the direction and speed of mouse movement into signals transmitted via standard PS/2 or USB interfaces, which are then sent to the computer.
But let’s delve a little deeper into the features of the sensor. The block diagram of the ADNS-3060 chip is shown above. As we can see, its structure has not changed fundamentally, compared to its distant “ancestors”. 3.3 Power is supplied to the sensor through the Voltage Regulator And Power Control block; the same block is charged with voltage filtering functions, for which a connection to an external capacitor is used. The signal coming from an external quartz resonator to the Oscillator block (the nominal frequency of which is 24 MHz; lower frequency master oscillators were used for previous models of microcircuits) serves to synchronize all computational processes occurring inside the optical sensor chip. For example, the frequency of images of an optical sensor is tied to the frequency of this external generator (by the way, the latter is not subject to very strict restrictions on permissible deviations from the nominal frequency - up to +/- 1 MHz). Depending on the value entered at a specific address (register) of the chip’s memory, the following operating frequencies for taking pictures with the ADNS-3060 sensor are possible.
| Register value, hexadecimal | Decimal value | Sensor snapshot rate, frames/s |
| OE7E | 3710 | 6469 |
| 12C0 | 4800 | 5000 |
| 1F40 | 8000 | 3000 |
| 2EE0 | 12000 | 2000 |
| 3E80 | 16000 | 1500 |
| BB80 | 48000 | 500 |
As you might guess, based on the data in the table, the frequency of sensor snapshots is determined using a simple formula: Frame rate = (Setting generator frequency (24 MHz)/Value of the register responsible for the frame rate).
Surface images (frames) taken by the ADNS-3060 sensor have a resolution of 30x30 and represent the same matrix of pixels, the color of each of which is encoded with 8 bits, i.e. one byte (corresponding to 256 shades of gray for each pixel). Thus, each frame (frame) arriving at the DSP processor is a sequence of 900 bytes of data. But the “cunning” processor does not process these 900 bytes of the frame immediately upon arrival; it waits until 1536 bytes of information about pixels are accumulated in the corresponding buffer (memory) (that is, information about another 2/3 of the subsequent frame is added). And only after this the chip begins to analyze information about the movement of the manipulator, by comparing changes in successive images of the surface.
With a resolution of 400 or 800 pixels per inch, their implementation is indicated in the RES bit of the microcontroller memory registers. A zero value of this bit corresponds to 400 cpi, and a logical one in RES sets the sensor to 800 cpi mode.
After the integrated DSP processor processes the image data, it calculates the relative displacement values of the manipulator along the × and Y axes, storing specific data about this in the memory of the ADNS-3060 chip. In turn, the external controller (mouse) chip, via Serial Port, can “draw” this information from the memory of the optical sensor approximately once every millisecond. Note that only an external microcontroller can initiate the transfer of such data; the optical sensor itself never initiates such a transfer. Therefore, the issue of efficiency (frequency) of tracking mouse movement largely lies on the “shoulders” of the external controller chip. Data from the optical sensor is transmitted in 56-bit packets.
Well, the Led Control block with which the sensor is equipped is responsible for controlling the backlight diode - by changing the value of bit 6 (LED_MODE) at address 0x0a, the optosensor microprocessor can switch the LED to two operating modes: logical “0” corresponds to the “diode is always on” state, logical “1” puts the diode into the “on only when necessary” mode. This is important, say, when operating wireless mice, as it allows you to save the power of their autonomous power supplies. In addition, the diode itself can have several brightness modes.
This, in fact, is all about the basic principles of operation of an optical sensor. What else can you add? Recommended working temperature ADNS-3060 chips, as well as all other chips of this kind, - from 0 0C to +40 0C. Although Agilent Technologies guarantees the preservation of the operating properties of its chips in the temperature range from -40 to +85 ° C.
Laser future?
Recently, the Internet was filled with praising articles about the Logitech MX1000 Laser Cordless Mouse, which used an infrared laser to illuminate the surface under the mouse. Almost a revolution in the field of optical mice was promised. Alas, having personally used this mouse, I was convinced that the revolution did not happen. But that's not what this is about.
I haven’t disassembled the Logitech MX1000 mouse (I didn’t have the opportunity), but I’m sure that behind the “new revolutionary laser technology” is our old friend - the ADNS-3060 sensor. Because, according to the information I have, the sensor characteristics of this mouse are no different from those of, say, the Logitech MX510 model. All the “hype” arose around the claim on the Logitech website that using a laser optical tracking system, twenty times (!) more details are detected than using LED technology. On this basis, even some respected sites have published photographs of certain surfaces, they say, how ordinary LED and laser mice see them :) 
Of course, these photos (and thank you for that) were not the multi-colored bright flowers with which the Logitech website tried to convince us of the superiority of the laser illumination of the optical tracking system. No, of course, optical mice did not “see” anything similar to the given color photographs from to varying degrees detail - the sensors still “photograph” nothing more than a square matrix of gray pixels, differing only in different brightness (processing information about the expanded color palette of pixels would place an enormous burden on the DSP).
Let's estimate that to get a 20 times more detailed picture, you need, excuse the tautology, twenty times more details, which can only be conveyed by additional pixels of the image, and nothing else. It is known that the Logitech MX 1000 Laser Cordless Mouse takes pictures of 30x30 pixels and has a maximum resolution of 800 cpi. Consequently, there can be no talk of any twenty-fold increase in the detail of images. Where did the dog go rummaging :), and aren’t such statements generally unfounded? Let's try to figure out what caused this kind of information to appear.
As is known, a laser emits a narrowly directed (with small divergence) beam of light. Consequently, the illumination of the surface under the mouse when using a laser is much better than when using an LED. A laser operating in the infrared range was chosen, probably, so as not to dazzle the eyes due to the possible reflection of light from under the mouse in the visible spectrum. The fact that the optical sensor works normally in the infrared range should not be surprising - from the red range of the spectrum, in which most LED optical mice operate, to the infrared - “at your fingertips”, and it is unlikely that the transition to a new optical range was difficult for the sensor. For example, the Logitech MediaPlay controller uses an LED, but also provides infrared illumination. Current sensors work without problems even with blue light (there are manipulators with such illumination), so the spectrum of the illumination area is not a problem for sensors. So, due to the stronger illumination of the surface under the mouse, we have the right to assume that the difference between the places that absorb radiation (dark) and reflect the rays (light) will be more significant than when using a conventional LED - i.e. the image will be more contrasty.
And indeed, if we look at real photographs of a surface taken by a conventional LED optical system and a system using a laser, we will see that the “laser” version is much more contrasty - the differences between the dark and bright areas of the image are more significant. Of course, this can significantly facilitate the work of the optical sensor and, perhaps, the future lies with mice with a laser backlight system. But such “laser” images can hardly be called twenty times more detailed. So this is another “newborn” myth.
What will the optical sensors of the near future be like? It's hard to say. They will probably switch to laser illumination, and there are already rumors on the Internet about a sensor being developed with a “resolution” of 1600 cpi. We can only wait.
