Create blank Arduino project for sensor node firmware.
Start testing by borrowing code from AdaFruit's DHTtester sketch
Add code to read from the light-dependant resistor.
Add code to drive the alarm beeper.

(Currently hard-coded to off, but testable by editing `is_alarming = 0`
 and recompiling.)
Hook is_alarming up to a simple approximation of the dewpoint formula.

This allows each node to have a direct, robust means to warn of conditions
that produce condensation and promote the growth of mould.

(Source: https://en.wikipedia.org/wiki/Dewpoint#Simple_approximation)
Switch output format to JSON in preparation for machine consumption.
Switch to more helpful variable names
Forgot pin 11 was used by the SPI bus. Move alarm to pin 10.
Add a blog post with pictures and Fritzing diagram for sensor nodes.