nodemcu-firmware/docs/lua-modules/lm92.md

LM92 Module

Since	Origin / Contributor	Maintainer	Source
2015-05-17	Levente Tamas	Levente Tamas	lm92.lua

This Lua module provides access to LM92 I²C ±0.33C 12bit+sign temperature sensor.

!!! note This module requires i2c C module built into firmware.

Require

lm92 = require("lm92")

Release

lm92 = nil
package.loaded["lm92"] = nil

lm92.setup()

Function used to setup the address for lm92.

Syntax

lm92.setup(address)

Parameters

• address: I²C address used by LM92. Depends on the connection of A0 and A1 pins. Can be either 0x48, 0x49, 0x4a or 0x4b according to page 9 of LM92 datasheet

Returns

nil

Example

lm92 = require("lm92")
sda = 3 -- GPIO 0
scl = 4 -- GPIO 2
addr = 0x48
i2c.setup(0, sda, scl, i2c.SLOW)  -- call i2c.setup() only once
lm92.setup(addr)

lm92.getTemperature()

Returns the temperature register's content.

Syntax

lm92.getTemperature()

Parameters

None

Returns

Temperature in degree Celsius.

lm92.shutdown()

Makes the chip enter the low power shutdown mode.

Syntax

lm92.shutdown()

Parameters

None

Returns

nil

lm92.wakeup()

Makes the chip exit the low power shutdown mode.

Syntax

lm92.wakeup()

Parameters

None

Returns

nil

lm92.setThyst()

Set hysteresis Temperature.

Syntax

lm92.setThyst(htemp)

Parameters

• htemp: Hysteresis temperature from 130 to -55 in ºC

Returns

nil

lm92.setTcrit()

Set Critical Temperature.

Syntax

lm92.setTcrit(ctemp)

Parameters

ctemp: Critical temperature from 130 to -55 in ºC

Returns

nil

lm92.setTlow()

Set Low Window Temperature.

Syntax

lm92.setTlow(lwtemp)

####Parameters

• lwtemp: Low window temperature from 130 to -55 in ºC

Returns

nil

lm92.setThigh()

Set High Window Temperature.

Syntax

lm92.setThigh(hwtemp)

Parameters

• hwtemp: High window temperature from 130 to -55 in ºC

Returns

nil

lm92.getThyst()

Get hysteresis Temperature.

Syntax

lm92.getThyst()

Parameters

None

Returns

Hysteresis Temperature in degree Celsius.

lm92.getTcrit()

Get Critical Temperature.

Syntax

lm92.getTcrit()

Parameters

None

Returns

Critical Temperature in degree Celsius.

lm92.getTlow()

Get Low Window Temperature.

Syntax

lm92.getTlow()

Parameters

None

Returns

Low Window Temperature in degree Celsius.

lm92.getThigh()

Get High Window Temperature.

Syntax

lm92.getThigh()

Parameters

None

Returns

High Window Temperature in degree Celsius.

Example

--node.compile("lm92.lua")
lm92 = require("lm92")
sda = 3 -- GPIO 0
scl = 4 -- GPIO 2
addr = 0x48
i2c.setup(0, sda, scl, i2c.SLOW)  -- call i2c.setup() only once
lm92.setup(addr)
 
t = lm92.getTemperature()
print("Got temperature: "..t.." C")

--Seting comparison temperatures
lm92.setThyst(3)
lm92.setTcrit(40.75)
lm92.setTlow(28.5)
lm92.setThigh(31.625)

t = lm92.getThyst()
print("Got hyster: "..t.." C")
t = lm92.getTcrit()
print("Got Crit: "..t.." C")
t = lm92.getTlow()
print("Got Low: "..t.." C")
t = lm92.getThigh()
print("Got High: "..t.." C")

TODO:

• add full support of the features, including interrupt and critical alert support