ESP8266 Powered Propane Poofer
Nick Poole 
Wire it up
If the propane bottles are the heart of this operation then the ESP8266 Thing is definitely the brains. The Thing board will allow us to connect to the flame cannon and fire it from a safe distance. Because the Thing can't source anywhere near the voltage or current necessary to fire the solenoid valves or light the igniter, we'll switch them using our Beefcake Relay kits. Our 12VDC power source needs to be portable, rechargable and capable of supplying a decent amount of current so I used a sealed lead-acid battery for a home alarm system. You can pick these up at most home improvement stores.
Here's what the whole project looks like once it's wired up:
For this project, an SLA battery was used as the power supply for the entire rig. However, the ESP8266 Thing Dev Board has a VIN tolerance of 3.3V and 6V. I DO NOT recommend powering your Thing Dev Board with the unregulated 12V. A 5V source was needed to properly power the Thing Dev Board as well as fire the relays. I sloppily wired in a 5V regulator which provided plenty of power at 5V to effectively switch the Beefcake Relays. Each relay's signal line was connected to a GPIO pin on the Thing, I chose 4, 0 and 13 only because they're side-by-side. Finally, the high side of the 12V line is switched by each relay before reaching the igniter and the two solenoid valves.
In order to recharge the SLA battery, I just throw it on my bench supply at about 14V until it stops drawing current. There are fancier ways to do this, but I'm happy with my system. I didn't find an external antenna necessary for the Thing to work at significant range thanks to the on-board trace antenna. If you want extra range, however, you can cut the antenna trace, add a U.fl to RP-SMA pigtail and screw on one of our big rubber duck antennas.
To keep the electronics safe and dry, I put them in a plastic ammunition box that I picked up at the hardware store. A bundle of cables comes through a hole in the side of the box and connects to the cannon. The whole unit doesn't weigh too much, and you can lean the cannon against the box to stabilize it.