55 lines
1.2 KiB
Lua
55 lines
1.2 KiB
Lua
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-- ***************************************************************************
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-- BH1750 module for ESP8266 with nodeMCU
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-- BH1750 compatible tested 2015-1-22
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--
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-- Written by xiaohu
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--
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-- MIT license, http://opensource.org/licenses/MIT
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-- ***************************************************************************
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local moduleName = ...
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local M = {}
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_G[moduleName] = M
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--I2C slave address of GY-30
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local GY_30_address = 0X23
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-- i2c interface ID
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local id = 0
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--LUX
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local l
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--CMD
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local CMD = 0x10
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local init = false
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function M.init(sda, scl)
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i2c.setup(id, sda, scl, i2c.SLOW)
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--print("i2c ok..")
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init = true
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end
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local function read_data(ADDR, commands, length)
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i2c.start(id)
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i2c.address(id, ADDR, i2c.TRANSMITTER)
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i2c.write(id, commands)
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i2c.stop(id)
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i2c.start(id)
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i2c.address(id, ADDR,i2c.RECEIVER)
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tmr.delay(200000)
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c = i2c.read(id, length)
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i2c.stop(id)
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return c
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end
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local function read_lux()
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dataT = read_data(GY_30_address, CMD, 2)
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UT = string.byte(dataT, 1) * 256 + string.byte(dataT, 2)
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l = (UT*1000/12)
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return(l)
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end
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function M.read()
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if (not init) then
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print("init() must be called before read.")
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else
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read_lux()
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end
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end
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function M.getlux()
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return l
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end
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return M
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