Over the past several months, I’ve found myself manually building the same circuit for my last two projects - the arcade and my internet connected mouse trap which hasn’t been released yet due to DHCP bugs. For the arcade, I needed to connect external buttons & joystick (Hydra Kiosk Kit) to the Hydra and for the mouse trap, I need to detect a break in a wire. These are basically the same problem and I didn’t want to ever have to take the time to throw it together again so I created the TripWire Module.
It allows for seven external switches or any other device that simply needs to detect an on/off state. There are LEDs for every switch that light when they are grounded. Four of the pins are made to allow male spade terminals for easy connection to the Kiosk kit or other external devices. All pins have ESD protection and should supply sufficient protection against devices connected via longer wires (such as is needed for mouse traps…).
These pictures are of my latest revision which is fully functional but still has few things that need fixing - primarily silk screen related. It seems that I was a beta tester for a new process at DFRobot… Also, I designed the circuit so that the LEDs could be enabled/disabled via solder junction to save power if needed (especially useful if you would be using it in a normally on state). Unfortunately, it seems that they aren’t disabled by default. I’m going to start looking over the board for defects but please look at my schematic and see if I did something dumb also.
I’ll probably do one more revision just because I want it perfect. Let me know if there’s anything you would change about it and I’ll incorporate it in. If anyone is in need of one of these now and can’t wait for the final revision, let me know. I have 50 of these… I’m hoping DFRobot is going to at least discount the next run since it seems it’s their fault that the keep away circles didn’t print.
The second photo is of the tiny ESD protection diode array. The part is at the tip of the toothpick. The pad is just below it.