nodemcu-firmware/lua_modules/tsl2561/tsl2561.lua

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-- ***************************************************************************
-- tsl2561.lua
-- Module for ESP8266 with nodeMCU
-- Ported from github.com/Seeed-Studio/Grove_Digital_Light_Sensor
--
-- Copyright (c) 2012 seeed technology inc.
-- Website : www.seeed.cc
-- Author : zhangkun
-- Create Time:
-- Change Log : 2015-07-21: Ported original code to Lua
-- by Marius Schmeding (skybus.io)
--
-- MIT License, http://opensource.org/licenses/MIT
-- ***************************************************************************
local TSL2561_Control = 0x80
local TSL2561_Timing = 0x81
local TSL2561_Interrupt = 0x86
local TSL2561_Channel0L = 0x8C
local TSL2561_Channel0H = 0x8D
local TSL2561_Channel1L = 0x8E
local TSL2561_Channel1H = 0x8F
local TSL2561_Address = 0x29 -- device address
local LUX_SCALE = 14 -- scale by 2^14
local RATIO_SCALE = 9 -- scale ratio by 2^9
local CH_SCALE = 10 -- scale channel values by 2^10
local CHSCALE_TINT0 = 0x7517 -- 322/11 * 2^CH_SCALE
local CHSCALE_TINT1 = 0x0fe7 -- 322/81 * 2^CH_SCALE
-- Scale table
local S = {}
S.K1T = 0x0040 -- 0.125 * 2^RATIO_SCALE
S.B1T = 0x01f2 -- 0.0304 * 2^LUX_SCALE
S.M1T = 0x01be -- 0.0272 * 2^LUX_SCALE
S.K2T = 0x0080 -- 0.250 * 2^RATIO_SCA
S.B2T = 0x0214 -- 0.0325 * 2^LUX_SCALE
S.M2T = 0x02d1 -- 0.0440 * 2^LUX_SCALE
S.K3T = 0x00c0 -- 0.375 * 2^RATIO_SCALE
S.B3T = 0x023f -- 0.0351 * 2^LUX_SCALE
S.M3T = 0x037b -- 0.0544 * 2^LUX_SCALE
S.K4T = 0x0100 -- 0.50 * 2^RATIO_SCALE
S.B4T = 0x0270 -- 0.0381 * 2^LUX_SCALE
S.M4T = 0x03fe -- 0.0624 * 2^LUX_SCALE
S.K5T = 0x0138 -- 0.61 * 2^RATIO_SCALE
S.B5T = 0x016f -- 0.0224 * 2^LUX_SCALE
S.M5T = 0x01fc -- 0.0310 * 2^LUX_SCALE
S.K6T = 0x019a -- 0.80 * 2^RATIO_SCALE
S.B6T = 0x00d2 -- 0.0128 * 2^LUX_SCALE
S.M6T = 0x00fb -- 0.0153 * 2^LUX_SCALE
S.K7T = 0x029a -- 1.3 * 2^RATIO_SCALE
S.B7T = 0x0018 -- 0.00146 * 2^LUX_SCALE
S.M7T = 0x0012 -- 0.00112 * 2^LUX_SCALE
S.K8T = 0x029a -- 1.3 * 2^RATIO_SCALE
S.B8T = 0x0000 -- 0.000 * 2^LUX_SCALE
S.M8T = 0x0000 -- 0.000 * 2^LUX_SCALE
S.K1C = 0x0043 -- 0.130 * 2^RATIO_SCALE
S.B1C = 0x0204 -- 0.0315 * 2^LUX_SCALE
S.M1C = 0x01ad -- 0.0262 * 2^LUX_SCALE
S.K2C = 0x0085 -- 0.260 * 2^RATIO_SCALE
S.B2C = 0x0228 -- 0.0337 * 2^LUX_SCALE
S.M2C = 0x02c1 -- 0.0430 * 2^LUX_SCALE
S.K3C = 0x00c8 -- 0.390 * 2^RATIO_SCALE
S.B3C = 0x0253 -- 0.0363 * 2^LUX_SCALE
S.M3C = 0x0363 -- 0.0529 * 2^LUX_SCALE
S.K4C = 0x010a -- 0.520 * 2^RATIO_SCALE
S.B4C = 0x0282 -- 0.0392 * 2^LUX_SCALE
S.M4C = 0x03df -- 0.0605 * 2^LUX_SCALE
S.K5C = 0x014d -- 0.65 * 2^RATIO_SCALE
S.B5C = 0x0177 -- 0.0229 * 2^LUX_SCALE
S.M5C = 0x01dd -- 0.0291 * 2^LUX_SCALE
S.K6C = 0x019a -- 0.80 * 2^RATIO_SCALE
S.B6C = 0x0101 -- 0.0157 * 2^LUX_SCALE
S.M6C = 0x0127 -- 0.0180 * 2^LUX_SCALE
S.K7C = 0x029a -- 1.3 * 2^RATIO_SCALE
S.B7C = 0x0037 -- 0.00338 * 2^LUX_SCALE
S.M7C = 0x002b -- 0.00260 * 2^LUX_SCALE
S.K8C = 0x029a -- 1.3 * 2^RATIO_SCALE
S.B8C = 0x0000 -- 0.000 * 2^LUX_SCALE
S.M8C = 0x0000 -- 0.000 * 2^LUX_SCALE
local moduleName = ...
local M = {}
_G[moduleName] = M
-- i2c interface ID
local id = 0
-- local vars
local ch0,ch1,chScale,channel1,channel0,ratio1,b,m,temp,lux = 0
-- Wrapping I2C functions to retain original calls
local Wire = {}
function Wire.beginTransmission(ADDR)
i2c.start(id)
i2c.address(id, ADDR, i2c.TRANSMITTER)
end
function Wire.write(commands)
i2c.write(id, commands)
end
function Wire.endTransmission()
i2c.stop(id)
end
function Wire.requestFrom(ADDR, length)
i2c.start(id)
i2c.address(id, ADDR,i2c.RECEIVER)
c = i2c.read(id, length)
i2c.stop(id)
return string.byte(c)
end
local function readRegister(deviceAddress, address)
Wire.beginTransmission(deviceAddress)
Wire.write(address) -- register to read
Wire.endTransmission()
value = Wire.requestFrom(deviceAddress, 1) -- read a byte
return value
end
local function writeRegister(deviceAddress, address, val)
Wire.beginTransmission(deviceAddress) -- start transmission to device
Wire.write(address) -- send register address
Wire.write(val) -- send value to write
Wire.endTransmission() -- end transmission
end
function M.getLux()
local CH0_LOW=readRegister(TSL2561_Address,TSL2561_Channel0L)
local CH0_HIGH=readRegister(TSL2561_Address,TSL2561_Channel0H)
--read two bytes from registers 0x0E and 0x0F
local CH1_LOW=readRegister(TSL2561_Address,TSL2561_Channel1L)
local CH1_HIGH=readRegister(TSL2561_Address,TSL2561_Channel1H)
ch0 = bit.bor(bit.lshift(CH0_HIGH,8),CH0_LOW)
ch1 = bit.bor(bit.lshift(CH1_HIGH,8),CH1_LOW)
end
function M.init(sda, scl)
i2c.setup(id, sda, scl, i2c.SLOW)
writeRegister(TSL2561_Address,TSL2561_Control,0x03) -- POWER UP
writeRegister(TSL2561_Address,TSL2561_Timing,0x00) --No High Gain (1x), integration time of 13ms
writeRegister(TSL2561_Address,TSL2561_Interrupt,0x00)
writeRegister(TSL2561_Address,TSL2561_Control,0x00) -- POWER Down
end
function M.readVisibleLux()
writeRegister(TSL2561_Address,TSL2561_Control,0x03) -- POWER UP
tmr.delay(14000)
M.getLux()
writeRegister(TSL2561_Address,TSL2561_Control,0x00) -- POWER Down
if(ch0/ch1 < 2 and ch0 > 4900) then
return -1 -- ch0 out of range, but ch1 not. the lux is not valid in this situation.
end
return M.calculateLux(0, 0, 0) -- T package, no gain, 13ms
end
function M.calculateLux(iGain, tInt, iType)
if tInt == 0 then -- 13.7 msec
chScale = CHSCALE_TINT0
elseif tInt == 1 then -- 101 msec
chScale = CHSCALE_TINT1
else -- assume no scaling
chScale = bit.lshift(1,CH_SCALE)
end
if (not iGain) then chScale = bit.lshift(chScale,4) end -- scale 1X to 16X
-- scale the channel values
channel0 = bit.rshift((ch0 * chScale),CH_SCALE)
channel1 = bit.rshift((ch1 * chScale),CH_SCALE)
ratio1 = 0
if channel0 ~= 0 then ratio1 = bit.lshift(channel1,(RATIO_SCALE+1))/channel0 end
-- round the ratio value
ratio = bit.rshift((ratio1 + 1),1)
if iType == 0 then -- T package
if ratio >= 0 and ratio <= S.K1T then
b=S.B1T
m=S.M1T
elseif ratio <= S.K2T then
b=S.B2T
m=S.M2T
elseif ratio <= S.K3T then
b=S.B3T
m=S.M3T
elseif ratio <= S.K4T then
b=S.B4T
m=S.M4T
elseif ratio <= S.K5T then
b=S.B5T
m=S.M5T
elseif ratio <= S.K6T then
b=S.B6T
m=S.M6T
elseif ratio <= S.K7T then
b=S.B7T
m=S.M7T
elseif ratio > S.K8T then
b=S.B8T
m=S.M8T
end
elseif iType == 1 then -- CS package
if ratio >= 0 and ratio <= S.K1C then
b=S.B1C
m=S.M1C
elseif ratio <= S.K2C then
b=S.B2C
m=S.M2C
elseif ratio <= S.K3C then
b=S.B3C
m=S.M3C
elseif ratio <= S.K4C then
b=S.B4C
m=S.M4C
elseif ratio <= S.K5C then
b=S.B5C
m=S.M5C
elseif ratio <= S.K6C then
b=S.B6C
m=S.M6C
elseif ratio <= S.K7C then
b=S.B7C
m=S.M7C
end
end
temp=((channel0*b)-(channel1*m))
if temp<0 then temp=0 end
temp = temp + bit.lshift(1,(LUX_SCALE-1))
-- strip off fractional portion
lux = bit.rshift(temp,LUX_SCALE)
return lux
end
return M