Arduino+XBee Dual-stage Temp Controller

[Chuginator]

That's not bad at all! I like it!

 

[hgmatt]

I was still having the same problem using the 3.3V option as well.

I suspect my problem is the frequency of readings per cycle, I was merely taking one per second or one per minute and it seems that the averaging of multiple per second would give better averages. I'll give it a shot, hopefully tonight.

As for shielding, I've read that you can install a 0.1uF ceramic capacitor across the TMP36 to reduce radio interference (look up the TMP35/36/37 datasheet).

 

[Chuginator]

Thanks for the tip!

 

[hgmatt]

New question, if you're logging the temperature, are you logging based on a date and time? Since the arduino does not have a "clock," are you time stamping the readings on the computer side instead of the arduino?

Lastly, do the xbee's act as a wireless usb cable?

 

[Chuginator]

Hi Matt,

Yes, the date/time is computer-side. When the packet comes in from the XBee, the PHP script just takes the current time and sticks it in the database along with the data.

XBees plug into your PC via a USB cable (FTDI cable), and appear to your OS as a serial port. So, think more like a modem.

I'd highly recommend "Wireless Sensor Networks" by O'Reilly/Robert Faludi. He really takes you by the hand and guides you through the nitty gritty of XBees.

 

[Chuginator]

I'm fermenting an EdWort IPA and realized that I could use SQL to compute how much I'm spending on energy for the heat tape. 53 cents so far! By the time it's finished, I might have a dollar in it.