Live sensor data feed from a WiSense node

You can see temperature and voltage reported by a WiSense node in real time here – https://xively.com/feeds/84250669.

The sensor node is located on the terrace.  It is operating in reduced functionality mode (RFD) and reporting the ambient temperature and the battery voltage. The temperature sensor is on board the MSP430G2955. The battery is a lithium coin cell (CR2032 from Maxell). The node is reporting both values every 5 seconds and it is two hops away from the network coordinator (located in my home office). The latter is connected to a Linux laptop through a USB to serial converter. The sensor data is being sent to the coordinator which forwards it over the serial port connected to the Linux laptop. A simple Linux app is reading the data from the serial port and posting to Xively using a “C” library API provided by Xively. You can download the library (libxively) here –  https://github.com/xively/libxively.

Xively is really easy to use. I was sending data to Xively within an hour of signing up for a developer account.

I created one device (Terrace_1). Every device has exactly one “feed” associated with it. A feed is a collection of channels (data streams) and associated metadata. This device “Terrace_1” has two channels. One channel reports the ambient temperature. This channel’s id is the string “TempSnsr_msp430”. The other channel reports the battery voltage. This channel’s id is the string “battVoltage”.

 

WiSense RFD  (source of temperature and voltage data)

rfd_terrace_pic

 

 

 

 

 

 

 

 

Router node (also on the terrace) relaying data between the RFD and the coordinator

router_terrace_pic

Posted on December 28, 2013, in Uncategorized. Bookmark the permalink. Leave a comment.

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