Any ideas on how making a good DHT11 sensor network? ( Arduino + XBee )

Question

I'm just starting out some studies with XBee S2 and Arduino and I'm not sure if I'm doing what I actually planned.

My idea was to use just one Arduino with one XBee (Coordinator) that would receive the DHT11 data from just Router XBee (without another arduino to process the DHT data) and save the Coordinator temperature and humidity in a database. Searching for some results I found out that XBee is unable to send DHT11 Sensor signal to another XBee ( thought I could send the DHT data through some router XBee Pin).

So do you guys have any ideas on how I could fix this? Because using another arduino into my Router XBee would be a waste of battery, losing the purpose of a sensor network right? Do you guys recommend me to change the sensor or what?

Besides I'm using Arduino Uno, Libellium XBee Shield, XBee S2 and of course DHT11.

Answer 1

Based on the DHT11 Adafruit page , I'd say you'll need an extra processor to read the data:

...and spits out a digital signal on the data pin (no analog input pins needed). Its fairly simple to use, but requires careful timing to grab data.

You may want to consider one of Digi's Programmable XBee products, which includes an additional 8-bit Freescale processor on the radio module, which you could program to read the DHT11 and relay its data to your coordinator. Certainly a less-expensive solution than having an Arduino make that conversion.

Or, switch to a humidity sensor with an analog output that doesn't require digital conversion. SparkFun has a Honeywell HIH-4030 Breakout board that looks appropriate.

If your goal is to just have a remote humidity sensor, one last option would be to purchase a standalone, battery-powered sensor from Digi. They have a light/temperature/humidity sensor (here's the datasheet ) with an XBee inside that should be easy to interface to your Arduino. It's been designed to run efficiently on batteries for an extended period of time. My understanding is that it uses the analog inputs of the XBee to relay the sensor readings.