LED Strip

 Cartesian coordinate conversion algorithm to the circle as follows [ 9 ] :

void ConCoor (int x, int y, int * rad, int * angle) {  LED Downlight

double r, a;

2.2 TLC5947 chip timing

TLC5947 sequence shown in Figure 3 , the chip has four main control pin [ 10 ] : a data input terminal SIN, the external clock input terminal SCLK, the grayscale register control terminal and an output control terminal XLAT BLANK. Through the data input port of the SIN gradation data required to end , and then control the clock signal SCLK to write data to the chip shift register, the gradation data ,

LED Strip 

and then by controlling the gradation register the control terminal of the high and low XLAT transform chip TLC5947 internal gradation data update. When XLAT pin level changes resulting from a rising edge , TLC5947 internal grayscale data will be updated once, in Figure 3, Grayscale LatchData be re- written. Chip data output in two parts , one part is the serial data output and data output constant current source . Serial data output is connected to the grayscale data shift register,

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 when the full 256-bit data register , you can change according to SCLK clock via a DQ flip-flop data from the serial data port SOUT terminal output , the port is mainly is a chip after chip cascade data input ; rather constant current source data output OUT0 ~ OUT23 is through output control port BLANK and chip clock Oscillator Clock comes to joint control , in which the output current through the chip size can be VREF pin external resistor to ground to control , according to the external LED 's self -limiting parameters to ensure LED work . The system uses a 3.2 kΩ resistor , so the chip control is mainly 4 pin port control, the operation is relatively simple and convenient.