My friend Matt came to me with an interesting idea. He had built a fireworks launcher with manual push-button controls, but he wanted to find a way to trigger the fireworks from a safer distance.
When the BBB received the ignite command, it changed the state of a particular GPIO pin that then triggered a relay to switch on a 12V current for a short period of time. That 12V current went to a small piece of nichrome wire that got red hot and ignited the fuse. It was important that the current stay on just long enough to ignite but not so long that it destroyed the wire.
The “patron” of the project had welded metal tubes to hold the fireworks. The launcher had four banks of 36 tubes each that held individual charges, with fuses running to the nichrome wire. All of this was on a metal trailer.
I had originally set the BBB up as a wifi access point using a small plug-in USB adapter. However, that didn’t give me enough range. Instead, I used a 12V router to create a wireless network. When the time came to set off the fireworks, I connected my tablet to the network and launched the web page, which I nicknamed “Beagle Blast.” As I tapped each button, the signals went to the fireworks and the buttons deactivated to help keep track of what had been launched.
The whole thing was powered by two car batteries: one for ignition and one for control, including 12V to power the relay boards and a 5V voltage regular that powered the BeagleBone Black.