LED lanterns have been widely used due to their rich lighting color, low cost and simple control. It has become fashionable to decorate streets and urban buildings with lanterns. This blog will share with you how to use the DragonBoard 410c development board to control the LED lights.
The programmable lanterns used in this design are shown in Figure 1:
figure 1
Basic parameters:
Color: full color
Waterproof rating: IP20 (not waterproof) / IP65 (Epoxy waterproof) / IP67 (casing waterproof) / IP68 (waterproof waterproof)
Wavelength: 620-630 (λ) 520-525 (λ) 465-470 (λ)
Light intensity: 500-600 (mcd) 900-1200 (mcd) 250-310 (mcd)
Luminous flux: 1.68 (lm) 3.2 (lm) 0.84 (lm)
Dimensions: 5000*12mm
Weight / volume: 300g
Angle of illumination: 120°
Working voltage: DC5V
Power: 10W/M
Number of LEDs/meter: 32LED/M IC Model: WS2801 Number of ICs per meter: 32 ICs
SPI control mode, data line, clock line has CLK, DAT
Control principle:An IC controls one LED to form a loop (a group), and the controller controls the circuit inside the FPCB through the control IC, thereby controlling different effects of the LED strip changes; such as blinking, chasing, jumping, clockwise, reverse When the clock is running, you can write your own code as needed.
The WS2801 has a local signal regeneration function. After receiving the rising edge signal, SCLKI ​​will internally generate a high-level pulse of 300ns, and use this pulse as the clock signal for signal transmission. At 2MHz signal frequency, 2048 points can be cascaded. At the same time, the frame rate reaches 30 Hz or more.
The WS2801 grayscale data structure is shown in Figure 2:
figure 2
The WS2801 data transmission timing is shown in Figure 3:
image 3
Since the voltage of the GPIO port of the DragonBoard 410c development board is 1.8V, and the voltage required by the WS2801 is 3.3V, a voltage conversion chip is required between the 410c board and the strip. The connection diagram of the DragonBoard 410c development board and the light strip is shown in Figure 4:
Figure 4
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