Happy 4th of July - PyroPro WebControlled Fireworks Board

thingiverse

This is a standalone board used to detonate fireworks safely from any web-enabled device. Simply stage your fireworks on the board, connect one of the premade ignitors to a channel output and the fuse of the firework, connect your smart device to the internal wireless router, pull up the control website, and fire each firework by remote web control. This is the safest way I've ever seen for an amateur to set off larger fireworks. It also has the added benefit of turning simple/cheaper fireworks into a small backyard show. Instead of lighting them off one at a time, you can sequence 8 different fireworks when and how you want. I normally start by setting off a fountain at the base of the board as a background, fire a Roman candle from one of the steel tubes for some upward amusement, mix in some sky rockets and artillery shells or two, and keep it going. It always seems to be a crowd pleaser. About 10 years ago, I moved from a state with almost no fireworks to one where I could get just about anything. When lighting off certain types of large fireworks like artillery shells and sky rockets, there was an apparent need to have the tubes and launch supports mounted to a solid structure. So, the idea for an actual board and some 2 ½ steel tubes (for stick-launched fireworks) mounted to the board was born. A few years later, we started experiencing boredom with having to hand-light each of the fireworks. I decided to pursue electronic detonation as a result. The first issue was the igniters. The most common ones used for model rockets were very pricey and hard to find in bulk. I did some research online and found a couple of people having success with pencil graphite, so I started experimenting using an 18V drill battery as my power source. I ended up perfecting the igniters a year later. The process is pretty straightforward and only requires super glue, Cat5e solid wire, and cheap No.2 pencils. The graphite is carefully removed from the pencil using wire dykes and a razor blade and then broken into ½” sections. From there, the Cat5e wire is stripped about 1” and either strand wrapped around the opposite side of the graphite. A small dab of super glue is used on each side of the wrapped wire. I can currently hand-make about 20 igniters in 10 minutes. Note that I noticed the cheaper the pencil, the better the ignition. This is because the cheaper pencil graphite pieces are less dense and not only heat up under current but crackle, which assists in lighting the firework fuses. Once the ignitors were figured out, an electronic detonation system was developed. I originally started with 6 channels and used a small 2-gang outlet box to house all of the relays. The detonator consisted of a small plastic box with an arm switch, arm light, and 6 PCB buttons. I used RJ45 jacks on both the board-mounted control box and the actual detonator. A 100’ spool of Cat5e patch cable was used to connect the detonator to the control box and to keep me out of harm's way. Two years ago, I decided to cut the cord and develop the wireless detonation system that was used this year. I wanted not only to be wireless but also to control the unit securely using my smartphone, tablet, or laptop. I used an Arduino Uno, Ethernet shield, some 74HC595 shift registers, 5V relays, and a WRT500G router to accomplish this task. The battery router, voltage regulators, and Arduino parts were laid out, and a design for custom control box was made. I fabbed the box out of 20-gauge sheet metal to act as a shroud from sparks and power. I finished the box off with high-temperature engine paint to try and protect from oxidation. A custom circuit board was made to fit, and then the programming started. I wanted to make use of AJAX feedback for this project so I could tell which state each of the control channels was in at any time. I wrote a simple HTML site loaded on a 2GB SD card for temp readout, master arm button, and firing channels. Each of the firing channels is on a 3-second delay so once the channel has fired, it turns off automatically to prevent any shorts. I wanted this to be a really safe control system as I would be putting my face next to each of the tubes while loading. So, joining to the wireless network is WPA2 password protected, there is a main power switch on the control box, the software has a master arm button, and the controller starts by grounding all pins. So, there is absolutely no power going to any of the firing channels unless everything is connected and switched to armed.