nodemcu-firmware/docs/lua-modules/hdc1000.md

HDC1000 Module

Since	Origin / Contributor	Maintainer	Source
2015-03-07	Francesco Truzzi	Francesco Truzzi	hdc1000.lua

This Lua module provides access to HDC1000 I²C digital humidity and temperature sensor. It should also work with HDC1008 sensor bout this haven't been tested.

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

Require

HDC1000 = require("HDC1000")

Release

HDC1000 = nil
package.loaded["HDC1000"] = nil

HDC1000.setup()

Function to setup the HDC1000 sensor.

Syntax

HDC1000.setup(drdyn)

Parameters

• drdyn: DRDYn pin number. If set to false, this feature will not be used and after each read request a 20ms delay will be added.

Returns

nil

Example

local sda, scl = 3, 4 -- Pins 3 and 4 will be used
local drdyn = 6 -- Pin 6 will be used to connect with DRDYn pin
i2c.setup(0, sda, scl, i2c.SLOW)  -- call i2c.setup() only once
HDC1000.setup(drdyn)

HDC1000.config()

Function to configure various options of HDC1000 sensor.

Syntax

HDC1000.config(address, resolution, heater)

Parameters

• address: I²C sensor address. Default value is 0x40.
• resolution: Temperature and humidity sensor resolution. Can be set to 14 bits for both temperature and humidity (0x00), 11 bits for temperature (0x40), 11 bits for humidity (0x01) or 8 bits for humidity (0x20). Default value is 0x00.
• heater: Heater setting. 0x20 to enable and 0x00 to disable. Default value is 0x20.

Returns

nil

HDC1000.getTemp()

Reads the temperature from HDC1000 sensor.

Syntax

HDC1000.getTemp()

Parameters

None

Returns

Temperature in Celsius degrees.

HDC1000.getHumi()

Reads the humidity value from HDC1000 sensor.

Syntax

HDC1000.getHumi()

Parameters

None

Returns

Humidity in percents.

HDC1000.batteryDead()

Function that checks if voltage of sensor power supply is bellow or above 2.8V.

Syntax

HDC1000.batteryDead()

Parameters

None

Returns

true if battery voltage is bellow 2.8V, false otherwise.

Example

HDC1000 = require("HDC1000")

sda = 1
scl = 2
drdyn = false

i2c.setup(0, sda, scl, i2c.SLOW)  -- call i2c.setup() only once
HDC1000.setup(drdyn)
HDC1000.config() -- default values are used if called with no arguments. prototype is config(address, resolution, heater)

print(string.format("Temperature: %.2f °C\nHumidity: %.2f %%", HDC1000.getTemp(), HDC1000.getHumi()))

HDC1000 = nil
package.loaded["HDC1000"] = nil