Dallas Temperature Sensor

Software

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

Before downloading the sketch to the Arduino you need to select a unique RADIO_ID (see top of sketch source code). The RADIO_ID must be unique in your radio network and is also used on the Vera side to distinguish between different sensors. After updating RADIO_ID and downloading the code you should be ready to go.

Wire things up

Follow the instructions in ConnectingRadioModule to connect radio module.

You can connect many DS18b20 in parallel if you want to collect several temperatures (they will be presented as separate devices in Vera). In the sketch provided I've used digital pin 2 for input.

You need connect a pull-up resistor like the picture show.

If you're still confused on how to wire up multiple DS18B20 please check out this page:
​http://klinkfamilyadventures.blogspot.se/2012/06/solar-hot-water-temperature-monitoring.html

Hardware - Purchase guide

This is the stuff you need to purchase to build the DallasTemperatureSensor. Note that I've provided links to the things I bought during the development. You might find it cheaper somewhere else. Also note that you might need to buy like 10x of some items to get the price specified.

1x Cheap Arduino Nano without serial interface and usb connector
​http://www.aliexpress.com/item/16Pcs-Lot-Pro-Mini-Module-Atmega328-5V-16M-For-Arduino-Compatible-Nano/710613095.html

8x Dupont cable Female->Female (you might need 3 extra depending on how your DS18b20 is hooked up)
​http://www.aliexpress.com/item/New-Female-To-Female-40-pcs-Wire-Cable-Line-1p-1p-Pin-Connector-20cm-2-54mm/1045212486.html

1x NRF24L01+ wireless data transmission module 2.4Ghz
​http://www.aliexpress.com/item/Free-shipping-NRF24L01-wireless-data-transmission-module-2-4G-the-NRF24L01-5PCS-LOT-upgrade-version-New/603756080.html

1x Waterproof DS18b20 temperature sensor
​http://www.aliexpress.com/item/5pcs-lot-Waterproof-DS18b20-temperature-probe-temperature-sensor-Stainless-steel-package-100cm-wire/520592929.html

1x Pull up resistor (4k7)
​http://www.aliexpress.com/item/300pcs-Resistors-4-7K-4K7-Ohm-1-4W-5-Carbon-Film-Free-Shipping/579559008.html

(You might later need some housing and transformer or battery compartment as well)

TOTAL SENSOR PRICE: $3,99 + $0.93 + $0,6 + $1.66 +$0.02 = $7,2

To download code to the cheapest Arduino Nano sensors (that is missing the serial USB port) you need to buy one of following as well. It is only attached while downloading code and can be reused between sensors.

1x Serial to USB adapter to download code to cheap Arduino Nanos
​http://www.aliexpress.com/item/Free-Shipping-FT232RL-USB-To-Serial-Adapter-Module-USB-TO-232-For-Arduino-Download-Cable/827218126.html