Temperature and Humidity sensor (DHT11/DHT22) ¶

Software ¶

You can download the Arduino sketch here:
http://code.mios.com/trac/mios_arduino-sensor/browser/trunk/Arduino/HumiditySensor

This sensor sleeps most of the time. You can change the sleep interval by updating SLEEP_TIME define at the top of the file.

Wire things up ¶

Follow the instructions in ConnectingRadioModule to connect radio module.

To connect the DHT22 sensor to the Arduino board follow these instructions:
Pin1. Connect VCC of the DHT22 sensor to +5V
Pin2. Connect Data to digital pin 3 of the Arduino board
Pin3. Not used.
Pin4. Connect to Ground

Use also need a pull up resistor between +5V and Data. See picture below.

Hardware - Purchase guide ¶

To build this sensor you'll need one arduino + radio specified in the base kit found here:
http://code.mios.com/trac/mios_arduino-sensor/wiki/WikiStart#Buyingguide
With the following additional parts:

1x DHT22 Temperature and Humidity sensor (there also exist a cheaper humidity sensor called DHT11 that is less accurate but half the price).
​http://www.aliexpress.com/item/1pcs-DHT22-digital-temperature-and-humidity-sensor-Temperature-and-humidity-module-AM2302-replace-SHT11-SHT15-Free/1031321543.html

TOTAL SENSOR PRICE: $7,6 (arduino + radio) + $4,99 (DHT22) = $12,6