Guest post: Building my “Simon Says” smart cache

This guest post, detailing how to build an awesome Simon Says type gadget cache, is by Hyliston, a Geocacher from Massachusetts. It originally appeared on his own Geocaching blog, on April 29th, 2016. You can read more about him at his nicely done profile.

I actually built this cache last summer, but still get tons of requests for instructions on how to make it. I didn’t document everything as I went, but this should help people who are interested in building something similar.

Inside Simon Says

The cache page for GC5PTYV: Simon Says can be found here.

The Cache Container

I did not take many photos of the container as I was building it.  Sorry.  But here a few things I kept in mind as I figured out the final dimension:

  • I needed the main panel to fit the four buttons and a 3 AA battery holder
  • I wanted to use a metal Pokémon tin as the cache container, so I had to make sure the cache compartment was big enough to hold it
  • I wanted the cache door to open on its own, so I had to leave space for a latching mechanism

I knew I wanted to try to make the outer container as a birdhouse.  So, the main button panel and the cache container determined the width and total height of the birdhouse, while the depth of the Pokémon tin determined the depth of the birdhouse.  It actually ended up being pretty close to the dimensions for a bluebird house.

I ended up building the birdhouse out of red oak, which was a mistake: it is HEAVY!  I was concerned about the steel pole holding it up properly, but it seems to be doing a good job, along with the tree behind it at the final location.  Because people will be pressing the buttons, I’d recommend some kind of object behind you final cache, so that they don’t push the whole thing over.

Simon Says Open by marcipanek
Simon Says Open by marcipanek
Simon Says Latching Mechanism
Simon Says Latching Mechanism

You can see the steel pipe and tree behind the cache in the left photo.  In the right photo, you can see the latching mechanism in more detail.  The bolt with the spring around it is slightly compressed when the door is closed, and pushes the door open when the latch releases.  Above the bolt, you can see a bent piece of metal with an orange wire tied around it.  It acts as the latch. A small hole is drilled for the wire to go through, which connects to the servo in the chamber above, which is where all the electronics are.  When the servo spins, it pulls on the orange wire, lifting the latch and allowing the springed-bolt to push open the door.

The Circuitry

For the circuit, I thought through what I wanted: an Arduino microcontroller, 4 different colored lights (preferable the same as the classic Simon game), 4 buttons, a speaker for sound, a way to power the cache, and a way to open the cache door.  Ideally, the 4 lights and 4 buttons should be the same object – that is, the buttons themselves should light up different colors.

The Prototype

Based on this, I decided to try and build a mock-up using parts I already had from Maker Shed’s Ultimate Arduino Microcontroller Pack, which my wife had gotten me for Christmas the previous year.

I made a video of the prototype in action:


You’ll notice a few compromises: all of the colors were red, the buttons and the lights were separate, and the power supply was coming straight from my computer over a USB cord.  This was just a proof of concept, and I was satisfied I could scale it up.  If you’d like to copy it, here is a circuit diagram of the prototype (minus the servo) from Sparkfun:

Simon Says Prototype Fritzing Diagram
Simon Says Prototype Fritzing Diagram

The Final Circuit

Here is a parts list for the final version (remember, I used small parts from a kit to prototype it), along with a rough cost in USD.  I have no affiliation with Adafruit.

You’ll also need a bunch of M-M jumper wires.  The servo can pull over 600 mA of current, which is why I went with Adafruit’s PowerBoost 1000 as my voltage converter.  When I tried a lesser step-up converter or a 9V battery connected directly to the Arduino, the circuit would brown out and fail when a signal was sent to the servo.  Short of plugging the whole thing into the wall, I never found another good solution for supplying power.  I also went with a slightly more expensive servo with metal gears.  I figure this will keep the gears from getting stripped.

Between the wood, hinges, electronics, etc., this cache is likely to cost you $100.  Keep that in mind when you determine if you want to build it and where you want to place it.  I ended up putting mine in a somewhat out-of-the-way location and making it a multi so that it takes a bit of work to find.

You don’t have to, but I also swapped out the LEDs and diodes that came with the arcade buttons with ultra-bright LEDs.  You can read more about my LED experiments here.

The Program

While I’m sure this would have been great fun to code from scratch, I started with some “Simon” code from a guide on  This code does way more than I need to it, including a head-to-head memory battle.

So, I started by stripping out anything that wasn’t for the one-player game.  I am playing a song, but not the entire Bee Gee’s Stayin’ Alive, so I also got rid of a bunch of musical note definitions that piezo buzzer wouldn’t use.  I also dropped the requirement to win from 13 to 10.  You’re welcome.   If you want to be a real bastard, feel free to increase that number (line 87) and the speed at which the buttons light up (line 170).

If you look at the top image of this post, which is the inside of my Simon Says cache, you may notice that there isn’t an Arduino UNO board in the picture.  I wasn’t willing to leave the $25 micro-controller in my cache, so I just used the main integrated circuit, an ATMEGA-328P.  It’s the long black rectangular thing in the middle-bottom.  I attached a timing crystal and two capacitors and it acts like a stripped-down Arduino.  All just to save $20.   I did a lot of reading to figure out how to do that, and unless you do too, your cache will look different than mine (because you’ll have a full Arduino inside yours).  Fair warning.

If I had to do it again, I’d probably just get an Arduino Nano and leave it in the breadboard, just like my Shave and a Haircut cache.  If you were to do that, your circuit diagram would look something like this:

Simon Says Wiring Diagram
Simon Says Wiring Diagram

The Final Result

Here is the cache in my shop.  The blue light is a bit dim, but it is much better in person.  This video is in the Hint for the cache.


If you decide to put a “Simon” cache out in the wild, please let me know!  I’d love to follow it and see the reactions of geocachers in your neck of the woods.  Thanks and good luck!

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An interview with Geocaching Vlogger Geohnny Cache

Above is the YouTube trailer video from Geocaching Vlogger Geohnny Cache AKA Ron, username I’m Geohnny Cache (note the spaces). You may remember him one of the winners of some of our 5th Anniversary Pathtags that we gave away in a contest in February. We knew of him from him being very well connected in the Geocaching Twittersphere at the time, and when we announced we were going to start getting back into news and interview blogging at the OCNA blog, he was the first person we thought of. He graciously agreed to do the interview.

OCNA Blog: Where are you from?

Ron: I am from Detroit, Michigan, I grew up on the Eastside of Detroit. After meeting my wife, we lived in a suburb of Detroit and about 7 years ago moved our family to St. Clair in the lower “thumb” of Michigan.

OCNA Blog: Many people have interesting stories how they heard about Geocaching, but yours is especially interesting as a Little Free Library owner. When did you install your LFL, and how did the whole thing happen with you first hearing about Geocaching as an LFL owner?

Ron: My Little Free Library/Geocaching story begins on Twitter, where I like to follow a few of my favorite authors. One day a picture was posted on an author’s account of a Little Free Library that contained one of his books. I thought, “Little Free Library, what the heck is that?” At first I was bewildered because I had never seen a LFL before and I immediately became intrigued and excited to learn more. Once I saw what the LFL movement was all about and the amount and variety of libraries around the world, I had to have one! I began to make plans and do more research.

My planning began in early Spring of 2014. By June, I had acquired a used wooden bookshelf that was perfect for building a library. With my Dad’s help we repurposed the shelf into a LFL.

It was through an online community of LFL Stewards that I had another “What the heck is that” moment. This time it was Geocaching. A fellow Steward asked if anyone had a Geocache in their LFL. Again, I was intrigued and excited to learn about something new. I did some researching and started by hiding a geocache in my LFL. (Although, I would recommend that a new geocacher spend more time finding and experiencing caches before hiding their own). Then I began geocaching myself and that’s when I became hooked! Networking is always a great way to learn and interact with people, so I started a Facebook page, Twitter, Instagram and a Youtube channel dedicated to sharing my geocaching adventures. I would also encourage new cachers to meet other cachers at Meet N Greets or other events. It’s a great way to learn and share stories.

OCNA Blog: After you started Geocaching, how long did it take before you found out there were many Geocaching Vloggers out there on YouTube, and that you would like to join their ranks? Had you made YouTube videos on any other topic before hearing about Geocaching?

Ron: Youtube was one of the first places I went to learn about Geocaching. The first videos I watched were by The Geocaching Vlogger, The GCDoc, and Geocaching with Darick. Their enthusiasm was contagious! I was intrigued by vlogging and knew this was what I wanted to do as a Youtuber. I have always enjoyed video making and editing for other personal or work projects but had never created my own channel. I followed the example. I watched in their videos and gave it a try. Of course the first few videos are rough as I got used to holding and talking to a camera and then actually finding the geocache. I have made 34 videos since that first one just over a year ago. I strive to make a video that is entertaining while showing the journey. Because after all, geocaching is about the journey not necessarily the cache itself. I tend to do less talking and let the scenery and music tell the story.

Soon after starting my channel, I joined The Geocaching Network. The GCNW is a hub for collecting youtube channels with the goal of promoting geocaching videos in a centralized location.

There are many other vloggers that I enjoy watching and we interact by commenting on each other’s videos. I would love to mention them all but would leave someone out my mistake. I am inspired by all of the vloggers on Youtube.

OCNA Blog: What gear do you use to make your videos?

Ron: My video making equipment is extremely simple. I use a point and shoot Sony Cyber-shot. I discovered that this still photo camera took way better video that my handheld video camera did. I attach it to a small handheld tripod. Recently though I upgraded my tripod to a VariZoom Stealthy. It can be configured into multiple setups and works great in the field.

My editing is done on a Macbook Pro with iMovie. I find that iMovie is simple yet really effective for editing.

I also carry a Geobag  that contains tools of the trade and swag.

OCNA Blog: Geohnny Cache is quite clever, Or would you have preferred Johnny Cache if that was available? How did you come up with that name?

Ron: I knew that Johnny Cache would have long been used so I came up with the alternate spelling of Geohnny and was excited to use it. For my geocaching user name I added “I’m” to the front to call myself “I’m Geohnny Cache”. That kind of reminds me of the beginning of the live Folsom Prison Blues when Johnny Cash says, “Hello, I’m Johnny Cash” (My Pathtag actually says that: “Hello, I’m Geohnny Cache”). On all social media I shortened the name to Geohnny Cache.

I’m a musician, so to have that caching name was pretty cool to me. I play guitar and mandolin professionally (I still have a day job) in a duo cover band called Smith & Tucker. I also play music with my dad and brother in a band called Runyons Branch. Music has always been a part of my family heritage, Classical on my Mom’s side and Bluegrass on my Dad’s.

OCNA Blog: We understand you’re one of the 5 rotating hosts of U.S. Geocaching Hour on Twitter.  Can you tell us a little bit about what that is, and how it works?

Ron: The #USGeocachingHour is a Tweetchat that occurs every Monday night at 9:00 ET, 8:00 CT, and is hosted by @USGeocaching. I was a regular participant and last December became one of the rotating hosts along with @geocachingVlogs, @GeoDarick, @myruggy89, and @geojosh13.

The tweetchat is a lot of fun and gives geocachers from all parts the opportunity to get together. The hour works like this; The host will run the show and ask geocaching related questions from the @USGeocaching account. Typically there will be 7 or 8 questions throughout the hour. Participants can answer/discuss the questions and/or have side chats. As long as everyone puts  #USGeocachingHour in their posts, all the participants can follow under the same feed.

I’ve enjoyed being a part of this team and especially collaborating on a Holiday Video we made together. (See below).

OCNA Blog:
Smartphone app, or handheld GPS? Which app do you prefer?

Ron: I started Geocaching with a Garmin 450. Last summer I upgraded my phone to a smartphone and now use an app. I am currently using Cachly a lot and I also use the original paid app from

OCNA Blog: Here’s a good one for a guy from Michigan. What are your Geocaching Temperature extremes? Coldest temperature in which you found a cache, and the hottest?

Ron: Michigan winters can be very extreme. I have been out in temps of single digits Fahrenheit with wind chills of ??. Winter caching can be especially challenging with  several inches or feet of snow on the ground. Because I started caching in Winter, I was determined to get out there. I kind of enjoy the stillness and beauty of a snow covered trail. One of my recent videos shows the beauty of a snowy trail as I went after a First to Find.

Michigan summers can reach 95 degrees with high humidity, so both times of year require good common sense and proper clothing and extras like hand warmers in winter, sun screen / water in summer.

OCNA Blog: Favorite Cache(s) so far?

Ron: I think one of my favorite caches was one called “What’s Worse than Thorns?” This cache was an ammo can hidden is a thick brush if thorny trees. The ammo can was filled with glitter and Red Herring containers. So after bushwacking to GZ, I had to dig through the glitter, open several containers to find the log.

Another favorite was a photo booth cache that my dad and I found in Kentucky. One of my Cachin’ in Coal Country videos show us dressing up and having some fun.The Hatfield and McCoy Geotrail was also one of my favorites because my dad grew up in that area of Kentucky/West Virginia. There is a lot of history there.

There are so many other caches that could be favorites, not necessarily because of the cache itself but because of the location or the time spent with family and friends.

OCNA Blog: It seems like the smartphone app Periscope is becoming popular with geocachers, including yourself. Can you tell us a little bit about that app, and how you have used it?

Ron: Periscope is an app where you can broadcast what you’re doing live and anyone that follows you can get a notification that you are “on” and watch your streaming video. When people watch your broadcast they can send messages on screen and you can verbally interact with them. It’s a great way to share a quick geocaching find and build an audience. The videos are available to view for 24 hours afterward. It’s also integrated with Twitter so your broadcast can be posted.

I have used it a couple of times for a geocache find. I have also used it on another account to share my son’s Marching Band shows with other band parents.

Geocaching with Periscope can be tricky if you are using the same Smartphone for both. I would recommend using a GPS as well or go with a friend.

Thanks to Ron for that great interview. Very informative For someone who is a “newer” Geocacher, we’d have to say he’s a natural! Here are some links, check them out!


To learn more about Little Free Libraries visit:

Visit Ron on Social Media:

Smith & Tucker:


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State of the Blog address

kc8nd7BEiThis blog will be three years old on Sunday, March 13th, 2016. We started out enthusiastically trying to be a general interest news and interview blog, of interest to all Geocachers, whether or not they used, or even gave a hoot about our website. Just trying to get our name out there, so to speak, while hopefully providing some fresh content, and making a few geo-friends in the process (the interviewees themselves). You may have noticed we’ve lost sight of that goal for the past year or so; although the blog is far from abandoned, we’ve only talked about/promoted ourselves. The last interview was in October, 2015, and could easily be considered “self promotion” about some Geocaching events listed on our site by Rob, AKA obxgeek, from Northern Virginia. Our last general interest Geocaching interview was with the then brand new Geocaching Vlogger Geocaching Kaity in late March 2015. We did have a little flurry of guest content (by our standards) on the blog in May and June2015, however.

A very little known fact is the WordPress installation that powers this blog was, in technical terms, “pretty messed up” the last few months! Those issues have been 100% fixed by our new web hosting company,! They did an outstanding job on our entire site, by the way. Hats off to them; highly recommended. So with that, why don’t we resolve to celebrate our 3rd birthday by “getting back into it a little”, and start aggressively pursuing some guest content, and bring you some Geocaching news and/or interviews (hopefully at least once a month). Because hey, with the It’s Not About The Numbers Blog having gone essentially silent (5 posts since May, 2014), someone has to do it! :-)

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OCNA 5th Anniversary Pathtag winners announced!

clipart-winnerAll three winners in our 5th Anniversary Pathtag contest have responded and claimed their prizes! We won’t disclose the number, but we had the most entrants of any contest we have ever held on this blog. This was surely due to sharing the blog post on Reddit, more specifically, the /r/geocaching sub-reddit, for those who know what we’re talking about there. The first prize winner of 5 of our Pathtags was Josh AKA radioguy949, a cacher from Idaho Falls, Idaho. The second prize winner of 3 of our Pathtags was  Ron AKA GeohnnyCache, a cacher from St. Clair, Michigan. He is also probably our most famous winner, as he is a Geocaching Vlogger, and you can check out, and subscribe to his YouTube channel here. The third prize winner, of a paltry 2 of our Pathtags was Constance AKA a member of the Jeepguyonline team, a cacher from Hesperia, California. Also, although we didn’t get permission to post his name, City and Geonick, we sent a consolation prize of 1 Pathtag to a “winner” who didn’t respond to the initial email in time according to the rules of the contest, but did respond to the “sorry, too late” email. Aren’t we nice? And we’ll prove it by duplicating this contest, and giving away 10 more to 3 winners in the Spring or early Summer, stay tuned. And remember, you can always buy your own OCNA 5th Anniversary Pathtags, still shown as the latest item for sale at

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Win some OpenCaching NA 5th Anniversary Pathtags!

frontAfter many delays, The OpenCaching North America 5th Anniversay Pathtag has finally been manufactured, and is on sale now! They can be purchased in lots of 20 for $20 from under a “club fundraiser” program. You’ll note the page for our tag on their website references us receiving $5 for every 20 pack sold. However, that applies only to registered non-profit LLC’s, one of which we are not (although we have, and still are considering, that legal status), so that $5 is payable only in Pathtag cash. The OCNA team will of course use this Pathtag cash to buy more of our own tags, which we will generously distribute to promote the website.

We will give you an example of that generosity right now. How about we give away 10 of them? Not to one person though, lets spread them around a little bit. We will have three separate winners. The 1st prize winner will receive 5 of our Pathtags; the 2nd prize winner will receive 3 of our Pathtags; and the 3rd prize winner will receive a paltry 2 of our Pathtags. These tags feature the OCNA Mascot Hank The Hawk, and were designed by Nancy of Deadliest Cachers, who also is the designer of Hank himself. They also feature the “free” OCNA Pathtag back that anyone can use for their tags (approved by October, 2105), which, you guessed it, was designed by Nancy. We are very happy they have finally been produced. If you don’t win any, you can always buy some. And remember, people love to trade for Pathtags, and “traders” who don’t even use our site, have bought packs of both this 5th Anniversary tag, and our 1st Edition tag from 2013.

To enter the Pathtag giveaway, fill out the form below with your name (as it says, “Geonick” is fine), and a valid email address. Entering as “Geonick” is indeed funny, but someone did it for one of our contests already, so it would be less funny this time. We will never use your email address, and the Google Document storing all the entries will be deleted after the contest. There are rules, of course, which appear below, in italicized text above the entry form.

Rules: To enter, provide your name and email address in the form below. One entry per person, and one entry per email address. There are no Geographical restrictions, contest is open to anyone in the world. The contest begins upon publication of this blog post on Friday, February 12th, 2016, and ends at 7:00 PM Eastern Standard Time on Sunday, February 21st, 2016. Three winners will be chosen at random from the entries received, shortly after the end time of the contest, using the services of the website Winners will be notified via email, notification being sent from the email address opencachingnorthamerica at (be sure to check your spam folders!), and must respond within 48 hours, or the prize will be forfeited, and another winner will be chosen. Once the prize is accepted, you must provide a valid mailing address, and the prize will be sent out via the U.S. Postal Service .

 Contest ended, entry form removed!

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