44 lines
1.1 KiB
Lua
44 lines
1.1 KiB
Lua
--
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-- Light sensor on ADC(0), RGB LED connected to gpio12(6) Green, gpio13(7) Blue & gpio15(8) Red.
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-- This works out of the box on the typical ESP8266 evaluation boards with Battery Holder
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--
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-- It uses the input from the sensor to drive a "rainbow" effect on the RGB LED
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-- Includes a very "pseudoSin" function
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--
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function led(r,Sg,b)
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pwm.setduty(8,r)
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pwm.setduty(6,g)
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pwm.setduty(7,b)
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end
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-- this is perhaps the lightest weight sin function in existance
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-- Given an integer from 0..128, 0..512 appximating 256 + 256 * sin(idx*Pi/256)
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-- This is first order square approximation of sin, it's accurate around 0 and any multiple of 128 (Pi/2),
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-- 92% accurate at 64 (Pi/4).
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function pseudoSin (idx)
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idx = idx % 128
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lookUp = 32 - idx % 64
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val = 256 - (lookUp * lookUp) / 4
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if (idx > 64) then
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val = - val;
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end
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return 256+val
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end
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pwm.setup(6,500,512)
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pwm.setup(7,500,512)
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pwm.setup(8,500,512)
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pwm.start(6)
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pwm.start(7)
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pwm.start(8)
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tmr.alarm(1,20,1,function()
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idx = 3 * adc.read(0) / 2
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r = pseudoSin(idx)
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g = pseudoSin(idx + 43)
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b = pseudoSin(idx + 85)
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led(r,g,b)
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idx = (idx + 1) % 128
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end)
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