Tweet-a-Watt XBee-Wifi

[mjrollins]

Hi there,

I was searching around and couldn't find an answer to this question...

I would like to build a tweet-a-watt; however, instead of using the regular XBee RF (which would require a receiver hooked up to a computer), I'd like to use WiFi.

Is it possible to swap out the existing XBee RF module for the XBee Wifi module (http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/point-multipoint-rfmodules/xbee-wi-fi#overview) to build a tweet-a-watt? Has anyone done this?

Thanks,
MJ

[adafruit_support_bill]

One possible issue would be the power requirements of the WiFi module. The Tweet-A-Watt is scavenging power from a supply just barely big enough to run the Kill-A-Watt. Sometimes it is even necessary to decrease the reporting frequency to avoid starving the Kill-A-Watt of power.

[mjrollins]

One possible issue would be the power requirements of the WiFi module. The Tweet-A-Watt is scavenging power from a supply just barely big enough to run the Kill-A-Watt. Sometimes it is even necessary to decrease the reporting frequency to avoid starving the Kill-A-Watt of power.

Thank you very much for your reply. Would it be practical to power the module externally (e.g. via a wall-wart or some similar power source)? Lowering the reporting frequency is quite acceptable, but I was just wondering what would make the project a bit easier to put together.

Thanks!

[adafruit_support_bill]

Would it be practical to power the module externally (e.g. via a wall-wart or some similar power source)?

Due to the design of the Kill-A-Watt, that could actually be quite dangerous. The 'ground' in the Kill-a-watt power supply is not an earth ground & connecting external circuitry could expose potentially lethal voltages outside of the case. If you search these forums, one user made an optically isolated circuit to safely transmit serial data outside the case. From there you could connect to your WiFi module.

[mjrollins]

Would it be practical to power the module externally (e.g. via a wall-wart or some similar power source)?

Due to the design of the Kill-A-Watt, that could actually be quite dangerous. The 'ground' in the Kill-a-watt power supply is not an earth ground & connecting external circuitry could expose potentially lethal voltages outside of the case. If you search these forums, one user made an optically isolated circuit to safely transmit serial data outside the case. From there you could connect to your WiFi module.

I had seen that post, and was hoping to avoid having to do that. I guess I could experiment with timings to see how long I should go between waking up the WiFi module. I'd honestly be more than satisfied with reading granularity on the order of 1-5 min

[faludi]

You could also consider using something like the ConnectPort X2 as a gateway, if you want a permanent installation that connects an XBee network to the Internet. It's dedicated hardware gateway from ZigBee to Ethernet, which is a good next step from using a full computer and wouldn't require changing anything on the Tweet-a-Watt. More info here on this option:
http://www.digi.com/products/wireless-r ... x2gateways
http://store.digi.com/index.cfm?fuseact ... ct_ID=2403

[mjrollins]

You could also consider using something like the ConnectPort X2 as a gateway, if you want a permanent installation that connects an XBee network to the Internet. It's dedicated hardware gateway from ZigBee to Ethernet, which is a good next step from using a full computer and wouldn't require changing anything on the Tweet-a-Watt. More info here on this option:
http://www.digi.com/products/wireless-r ... x2gateways
http://store.digi.com/index.cfm?fuseact ... ct_ID=2403

Snazzy. I know I should (and will) RTFM, but to understand this on a simple level, the ConnectPort will route the XBee traffic to a given IP address and port?

Thanks - this looks very promising in the short run though I'm still hoping to put together an all-in-one solution for this - but this is great.

[faludi]

Yes, and check out the XBee Internet Gateway http://faludi.com/xigfor a very easy way to post sampled I/O data to either iDigi Device Cloud http://idigi.com or any other online database of your choosing.