ماژول تشخیص رنگ TCS3200

این ماژول یکی از بهترین ماژول های تشخیص رنگ بوده که از سنسور TCS3200 استفاده می کند. در واقع این ماژول یک مبدل رنگ به فرکانس می باشد.
جهت تشخیص رنگ بایستی با میکروکنترلر فرکانس  پین خروجی  سنجیده شود.
ویژگی ها:
رزولوشن بالا
تبدیل نور به فرکانس
قابلیت تنظیم خروجی رنگ و محدوده ی خروجی
قابلیت اتصال به میکروکنترلر به صورت مستقیم
تغذیه 2.7 الی 5.5 ولت
خطا 0.2% در فرکانس 50KHz
پایداری ضریب دمایی 200ppm/C
 

The TCS3200 is a programmable color-to-frequency converter from TAOS that integrates a configurable silicon photodiode with a current-frequency converter on a single CMOS circuit while integrating red and green (RGB) on a single chip ) The three filters are the industry's first RGB color sensor with digital compatible interface. The TCS3200 's output signal is digital and can drive standard TTL or CMOS logic inputs, so it can be directly connected to a microprocessor or other logic circuit , It is possible to realize the conversion accuracy of 10 bits or more per color channel, and thus the A / D conversion circuit is no longer required to make the circuit easier .
The TCS3200 is available in an 8-pin SOIC surface mount package with 64 photodiodes integrated on a single chip. These diodes are divided into four types, with 16 photodiodes with a red filter; 16 photodiodes with green Filter; 16 photodiodes with blue filter, and the remaining 16 without any filter, through all the optical information, these photodiodes in the chip is cross-arranged, to minimize the incident light The non-uniformity of the radiation, thereby increasing the accuracy of color recognition; the other hand, the same color of the 16 photodiode is connected in parallel, evenly distributed in the diode array, you can eliminate the color position error. When working, the two filters are used to dynamically select the desired filter. The typical output frequency range of the sensor is from 2Hz to 500kHz. The user can also select 100%, 20% or more by two programmable pins. 2% output scale factor, or power off mode. The output scale factor enables the output of the sensor to accommodate different measuring ranges and improves its adaptability. For example, when a low-speed frequency counter is used, a small calibration value can be selected to match the output frequency of the TCS3200 to the counter.
When the incident light is projected onto the TCS3200, different filters can be selected by different combinations of the photodiode control pins S2, S3. After passing the current to the frequency converter, different square wave (duty cycle is 50%) is output. , Different colors and light intensity corresponding to different frequencies of the square wave; also through the output calibration control pin S0, S1, select a different output scale factor, the output frequency range to adjust to meet the different needs.
The following brief description of TCS3200 chip pin function and some of its combination options. S0, S1 is used to select the output scale factor or power off mode; S2, S3 is used to select the type of filter; OE is the frequency output enable pin, can control the output state, when there are multiple chip pins When the output pin of the microprocessor is also available as a chip select signal, OUT is the frequency output pin, GND is the chip's ground pin, VCC provides the operating voltage for the chip, Table 1 is available for S0, S1 and S2, S3 combination.
                
Three  TCS3200 to identify the principle of color
( 1 ) three primary colors of the sensor principle
The color of the object is usually seen, in fact, the surface of the object absorbs a part of the colored component of the white light (daylight) which is irradiated onto it, and the reflected part of the colored light in the human eye. White is composed of a variety of frequencies of visible light mixed together, that is, white light contains a variety of colors of light (such as red R, yellow Y, green G, green V, blue B, purple P). According to the German physicist Helmholtz (Helinholtz) theory of the three primary colors, we can see that the various colors are different proportions of the three primary colors (red, green, blue) mixed.
(2) TCS3200 to identify the principle of color
By the principle of the three primary colors to know, if you know the composition of the various colors of the three primary colors, you can know the color of the test object. For the TCS3200 , when a color filter is selected, it only allows a particular primary color to pass through, preventing the passage of other primary colors. For example, when a red filter is selected, only red can be passed through the blue, and blue and green are blocked, so that the light intensity of the red light can be obtained. At the same time, when the other filters are selected, blue and green Light intensity. With these three values, you can analyze the color of the light projected onto the TCS3200 sensor.
(3) white balance and color recognition principle
White balance is to tell the system what is white. In theory, white is made up of equal amounts of red, green and blue; but in fact, the three primary colors in white are not exactly equal, and for the TCS3200 's optical sensor, The sensitivity of the color is not the same, resulting in TCS3200 RGB output is not equal, so the white balance adjustment must be made before the test, making the TCS3200 on the detected "white" in the three primary colors are equal. The white balance adjustment is made for subsequent color recognition. In this device, the white balance adjustment of the specific steps and methods are as follows: the empty tube placed in the sensor above the tube above the placement of a white light source, so that the incident light can pass through the test tube on the TCS3200 ; according to the previously described Method, followed by red, green and blue filters, were measured red, green and blue values, and then you can calculate the need for three adjustment parameters.
When the TCS3200 recognizes the color, use the three parameters to adjust the color of the measured R, G and B. There are two ways to calculate the adjustment parameters : 1, followed by three filters, and then the TCS3200 output pulse in order to count. The count is counted when counting to 255, and the time used for each channel is calculated , which corresponds to the time base used by each filter at TCS3200 during the actual test. The number of pulses measured during this period is the corresponding R, G and B values. 2, set the timer for a fixed time (for example, 10ms), and then pass the three colors of the filter, calculate the period of time TCS3200 output pulse count, calculate a scale factor, by this scale factor can be the number of pulses To 255. In the actual test, the same time outside the outdoor count, the measured number of pulses multiplied by the obtained scale factor, and then you can get the corresponding R, G and B values.
1   size: 3CM * 2 .7 CM (length and width)
2  support 3V-5V voltage input;
** The best distance between the TCS3200 and the object to be tested is approximately 1 cm