74 lines
1.4 KiB
Markdown
74 lines
1.4 KiB
Markdown
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# BH1750 Module
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| Since | Origin / Contributor | Maintainer | Source |
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| :----- | :-------------------- | :---------- | :------ |
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| 2015-01-30 | [Martin Han](https://github.com/MarsTechHAN) | [Martin Han](https://github.com/MarsTechHAN) | [bh1750.lua](../../lua_modules/bh1750/bh1750.lua) |
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This Lua module provides access to [BH1750](https://www.mouser.com/ds/2/348/bh1750fvi-e-186247.pdf) I²C ambient light sensor.
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!!! note
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This module requires `i2c` C module built into firmware.
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### Require
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```lua
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bh1750 = require("bh1750")
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```
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### Release
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```lua
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bh1750 = nil
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package.loaded["bh1750"] = nil
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```
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## bh1750.init()
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Initializes the module and sets up I²C with hardcoded device address.
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#### Syntax
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`bh1750.init(sda, scl)`
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#### Parameters
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- `sda` SDA pin number.
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- `scl` SCL pin number.
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#### Returns
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`nil`
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## bh1750.read()
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Reads lux value from the sensor.
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#### Syntax
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`bh1750.read()`
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#### Parameters
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None
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#### Returns
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Lux value.
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## bh1750.getlux()
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Function used to return last read lux value.
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#### Syntax
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`bh1750.getlux()`
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#### Parameters
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None
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#### Returns
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Last known lux value.
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#### Example
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```lua
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SDA_PIN = 6 -- sda pin, GPIO12
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SCL_PIN = 5 -- scl pin, GPIO14
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bh1750 = require("bh1750")
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bh1750.init(SDA_PIN, SCL_PIN)
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bh1750.read()
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l = bh1750.getlux()
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print("lux: "..(l / 100).."."..(l % 100).." lx")
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-- release module
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bh1750 = nil
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package.loaded["bh1750"] = nil
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```
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