Detailed Description:
TCS3200 is TAOS company launched the programmable color light-to-frequency converter, which the configurable silicon photodiode and current-frequency converter integrated on a single CMOS circuits, simultaneously on a single chip integrated green and blue (RGB ) of three filters, the industry's first digital-compatible interface with the RGB color sensor, TCS3200 output signal is digital, can drive standard TTL or CMOS logic input, it can be directly to a microprocessor or other logic circuits connected, since the output is digital, and each color channel can be achieved than 10-bit conversion accuracy, eliminating the need for A / D conversion circuit, the circuit becomes simpler.
TCS3200 8-pin SOIC surface-mount package, integrated on a single chip photodiode 64, the diodes are divided into four types, and its 16 photodiode with a red filter; 16 photodiode with a green filter; 16 photodiode with a blue filter, and the remaining 16 without any filter, the optical information through all of these photodiodes are arranged in cross the chip, capable of minimizing the incident light uniformity of radiation, thereby increasing the accuracy of color identification; other hand, the same color photodiodes 16 are connected in parallel, uniformly distributed in the diode array, the position error can be eliminated color.
Work, through two programmable pin to dynamically select the desired filter, the sensor has a typical output frequency range from 2Hz-500kHz, users can also choose two programmable pins to 100%, 20% or 2% of output scale factor, or power shutdown mode. Output scale factor of the sensor output can adapt to different measurement ranges, improved its ability to adapt. For example, when using a low-frequency counter, you can select a small scaling value, the output frequency and the counter TCS3200 match.
When the incident light is projected onto the TCS3200 on, through the control pin photodiode S2, S3 different combinations, you can choose different filters; through the current to frequency converter after the output of different frequency square wave (50% duty cycle) different colors and light intensity corresponding to different frequency square wave; Output Scaling can also control pin S0, S1, select different output scale factor, the output frequency range to be adjusted to accommodate different needs.
The following briefly describes the function of each pin TCS3200 chip and it's some combination of options. S0, S1 is used to select the output scale factor or power shutdown mode; S2, S3 is used to select the type of filter; OE counter is the frequency output enable pin that can control the output of the state, when there are multiple chips are pin-shared microprocessor output pin can also be used as a chip select signal, OUT is the frequency output pin, GND is the chip ground pin, VCC for the chip to provide operating voltage, Table 1 S0, S1 and S2, S3 availablecombinations.
TCS3200 color recognition principle
(1) The induction principle RGB
Color of objects commonly seen, in fact, the surface is irradiated to it absorbed white (daylight) part of the colored components, while reflecting the other part of a colored light in the human eye response. White is a mixture of various frequencies together to form a visible, that contains a variety of white color shade (such as red R, yellow Y, green G, blue V, blue B, purple P). According to the German physicist Helmholtz (Helinholtz) theory shows that the three primary colors, each color is different proportions of the three primary colors (red, green, blue) mixture.
(2) TCS3200 color recognition principle
Induction principle known by the three primary colors, if you know the three primary colors to create various color values, we can know the color of the object being tested. For TCS3200, when selecting a color filter that allows only through a particular color, to prevent the adoption of other colors. For example: When you select the red filter, the incident can be only red, blue and green are blocked, so that you can get the red light intensity; also choose other filters, you can get a blue light and green light intensity. By these three values can be projected onto the TCS3200 analyze the color of light on the sensor.
(3) white balance and color recognition principle
White balance is to tell the system what is white. Theoretically, the same amount of white is the red, green and blue mixture; but in reality, the white is not entirely the same in the three primary colors, and for TCS3200 optical sensors, which of these three basic The sensitivity is not the same color, resulting in the RGB output TCS3200 not equal, so the white balance adjustment must be carried out before the test, so that the detected TCS3200 "white" in the three primary colors are equal.
White balance adjustment is to prepare for the subsequent color recognition.In this apparatus, white balance adjustment, and the specific steps are as follows: the empty tubes placed over the sensor, placed on top of the test tube a white light source, the incident light can pass through the tube irradiated TCS3200; previously described under The method of sequentially gated red, green and blue filters, respectively, the measured red, green and blue values, and can calculate the required adjustment of the three parameters.
When TCS3200 identify colors, use these three parameters on the measured colors R, G and B to adjust. There are two ways to calculate the adjustment parameters: 1, followed by gating three color filters, and then turn on the TCS3200 output pulses are counted. When the count from 255 to stop counting, were calculated for each channel used in time, which corresponds to the actual test, each filter is used TCS3200 time reference measured at this time is the number of pulses corresponding to the R, G and B values. 2, the timer is a fixed time (e.g. 10ms), and three color filters strobe calculated TCS3200 this time the number of output pulses to calculate a scaling factor, the scaling factor by these pulses becomes 255. In the actual test, the outdoor same time for counting the number of pulses measured and multiplied by the scale factor obtained can then be obtained corresponding to the R, G and B values.
Modules Functional Description
1. Baby Size: 3CM * 2.7CM (length and width);
2. Interface Definition: VCC GND supply;
3. SO-S3 E0 OUT Communication Interface;
4. Onboard TCS3200 color sensor;
5. Supports 3V-5V voltage input;
6. Pin chip has all the leads, pin standard 100mil (2.54mm), easy for lattice panels;
7. Module testing a variety of colors exist a certain color, the color demanding test after careful consideration, please purchase;
8. TCS3200 the object to be tested with the best distance of about 1cm.
