With the winter months not far off, [Ben Brooks] was looking for a way to help circulate the heat from his wood-burning fireplace throughout his home. Rather than go with a commercial solution, he decided to come up with his own automated air circulation system powered by the mesh networking capabilities of one of his favorite pieces of tech, the Particle Photon.
The idea here is pretty simple: use a remote temperature sensor to tell a fan located behind the fireplace when it’s time to kick on and start sharing some of that warmth with the rest of the house. But as usual, it ended up being a bit trickier than anticipated. For one, when [Ben] took a close look at the Vornado 660 fan he planned on using, he realized that its speed controller was “smart” enough that simply putting a relay on the AC line wouldn’t allow him to turn it on and off.
So he had to do some reverse engineering to figure out how the Sonix SN8P2501B microcontroller on the board was controlling the fan, and then wire the Photon directly to the pins on the chip that corresponded with the various physical controls. This allows the Photon to not only “push” the buttons to trigger the different speeds, but also read the controls to see if a human is trying to override the current setting.
For the remote side [Ben] is using a Particle Xenon, which is specifically designed for Internet of Things endpoints and sensor applications. Combined with a TMP36 temperature sensor and 3.7 V 500 mAh battery, this allowed him to easily put together a wireless remote thermometer that will publish the current temperature to the Photon’s mesh network at regular intervals.
This isn’t the first time we’ve seen the Particle Photon used to augment an unassuming piece of hardware. We’ve previously seen one get grafted into a coffee maker, and if you can believe it, somebody even stuck one inside an umbrella to create a mobile weather station.