The next step in making my autonomous Arduino Nerf sentry gun is to move the relay circuit from the temporary breadboard onto something more durable and permanent, yet easy to connect. Wires from the Arduino and the trigger switch jack will need to connect through the relay board.
I soldered the relay, diode and some screw terminal connectors onto a piece of perfboard. I connected the appropriate leads using small bits of wire I’d snipped off of some LEDs for a previous project. One hilarious/awful bit of troubleshooting I had to do was due to a hidden connection between every three pads on my original perfboard. Once I realized what was going on, I re-soldered things onto a more appropriate board.
Finally, I wired up the relay coil terminals to open and close from a timed test sketch on an Arduino. When the coils were energized, my multimeter beeped to indicate the closing of the switch. This is exactly what will need to happen to fire the Nerf gun.
In the Maker Shed: