Particle-Driven LED Pumpkin Patch

How it started

We got talking at lunch about carving pumpkins, which turned into talking about lighting them up, which turned into getting very excited about using Particle devices to let people change the colors with their smartphones.

We’ve done loads of work with Particle devices the past year and have several kicking around, so they were the natural choice as a WiFi-connected micro-controller.

Get to work

Taylor wired up a prototype pretty quickly, and with a bit of code written for both the device and a web server. We used Porter to test things out.

That worked, so we started coding the mobile web page. We could have used Porter in this case as well, with the Share Interface feature, but we wanted to provide more of a Halloween specific experience.

Beyond the prototype, we soldered together five mini-boards with the Particle and LED, to be powered by a USB cable that would run into the back of the pumpkin.

Troubleshooting!

With everything set up we ran into a tricky problem: the devices kept losing their WiFi connection with no real pattern we could see. We tried moving the router, keeping the lids off the pumpkins, and even thinning the back wall of the pumpkins, but nothing helped.

Frustrated, we set up events on the devices to monitor when connection was lost. Since Porter stores events, we could look back at the overnight data and saw, to our horror, the devices were able to stay connected only for a few minutes before having to re-find their connection.

Porter's stored events showed us a lot of disconnection happening overnight. Dealbreaker territory! First thing in the morning, we rejigged our WiFi setup and lo, the devices connected solidly. Whew!

The extra step

This installation will only really work well at night and over this weekend when we’re away. We wanted to know if people used it, so we added one more event for color changes.

Once again, Porter filled in a gap: we made a custom action that watches for color events, and emails the pumpkin owner when their specific pumpkin is interacted with.

After the weekend, we’ll download all the stored events and see which pumpkins got the most love, and which colors people chose.

Lesson 1: WiFi is fickle

We all know this at some level, but it’s easy to forget. This is a part that we expected to ‘just work’ and it was one of the most time-consuming pieces to solve. We ended up building feedback into the UI just in case a color change fails to complete because of this.

Lesson 2: Fruit flies love pumpkins

These things are crazy. We’ve implemented an apple cider vinegar trap, and solemnly condemn these little guys to a drunken death.

You can skip the web stuff

Hey, if you're happy with some pumpkins that cycle through colors, you can do that with this project and skip all the web stuff. Not as interactive, but you'll still have one of the funnest pumpkin patches around. Good luck!