I am thinking of making fan coil thermostats, and one idea is to use the XBee for the purpose. The XBees would gather room teperature, heating fluid temperature, set temperature and then transmit that information to an Arduino. The Arduino would make a judgement and send back a command to activate two or three relays that actully represent the 2-3 speeds of the fan.
To cut the price, I was thinking to have XBee only solution (if possible) without having additional Arduino at the thermostat itself, only one central "decision making" arduino :
Seems though that the XBee doesn't have PWM, or at least this is what I read in the book "Building Wireless Sensor Networks: With ZigBee, XBee, Arduino, and Processing"
Quote: "On the Series 2 radios, there are currently no user-configurable analog or pulse-width modulated (PWM) outputs"
However, on http://www.makingthings.com/forum/devices/739804816 I read "After a quick look, it appears there are AT commands that control the PWM. After configuring the appropriate output as a PWM output, you can send the M0 or M1 AT commands with a value from 0-1023 to set the PWM duty of either PWM0 or PWM1 respectively.
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Anyone has experience with the matter?
