MP3 Sequence Caller

Seems as though I have a bad memory when it comes to memorizing a flying sequence or someone's name! Sad but true and it makes it pretty hard to practice a sequence when no one is around to call for you!

I usually fly at our club when there are only a hand full of members present at our field. I hate to impose on other members free time by asking them to stand out and call for me when I know they are not interested or would rather just relax. What is a person to do? How about record the sequence with a small tape recorder and play it back as I fly?   Great idea but how would I ever time the maneuvers to the flight?

One day my wife walked into my office with a small MP3 player and said "can you use this for something?" Being a gadget junky I said sure! The small MP3 player will hold up to 125 megabites of information in flash memory. I played around with it for a while and copied some music into the player and tossed it in my truck.

One day while relaxing at our club I was listening to the music on the MP3 player and watching the planes fly when I had a brain storm! Why not record each each maneuver in the sequence as its own MP3 file! Then I could advance to the next track each time I wanted a maneuvers called out to me! That would solve the timing issue during the flight, but then I need a way to advance the tracks while flying.

What I needed was a way to advance the tracks on the player with a remote switch. I decided to open up the MP3 player and see if I could connect a remote switch to the inside of the unit. I would only need the forward button for flying so that is what I looked for inside. After a couple of hours of trial and error I had the remote switch working! I decided to add a plug to the side of the unit so I could remove the remote switch if needed.

  

The remote switch was made from 2 small pieces of brass plate with a thin strip of plastic glued in between. Velcro holds the switch in place under my finger on the back side of my radio.

  

I fashioned a mount for the MP3 player out of styrene and used velcro to attach the mount to my radio. While flying all I have to do is push the button under my finger and the player advances to the next track or MP3.

  

My search led me to this text converter that works great.

I typed up the text of each maneuver exactly how I wanted it read to me and then pasted it into the link above. I saved each maneuver as a .WAV file on my computer. Using a free music editor to add in 30 seconds of silence after each maneuver and saved them as MP3 files. The 30 second delay gives me time to listen to the maneuver, fly it, then set up for the next maneuver. I can press the button any time during the 30 second delay to move forward to the next maneuver.

Here is a sample. This MP3 is for a Humpty Bump

So far this simple system works great. I have made some improvements to the second version. I will post details and pictures of the internal modification some time in the future.

My first version worked great but I wanted a way to change sequences at the field. Since these types of MP3 players will not allow you to divide music or MP3's into sub directories my only choice was to find a player that used a memory card.

I found this one for $24.00. It looked like it might work so I ordered it, It was perfect! It is held together by a couple of screws and once apart the switches where right on top and easy to get to.

The modification is really quite simple but a little delicate. You will need a small 15 watt soldering iron and a sharp tip. I use one from Radio Shack.

In the picture below I have pointed out the small tabs that you will need to solder to. This is the hardest part of the entire project. You will want to solder your wires to the "forward" button on your player.

For the plug I used some jumper pins off a old computer card I had laying around. I un-soldered them and attached it to the plastic case of the MP3 player with a little epoxy. You could use a servo plug, mini deans connector, or whatever you have laying around in place of the jumper pins.

Now run your wires to the remote switch plug, solder and you are finished.

Put everything back together and test it out.

I will post some pictures of my radio mount in a few days when I have time. I hope you enjoy your new sequence caller as much as I do!

Disclaimer: Please read

The plans, instructions, parts list, drawings or any of it's parts are not to be used for monetary gain. You must have written permission for submittal to any form of magazine or publication and proper credit must be given to it's author.

You may print or electronically duplicate the files for your personal use only.

Although all due care is taken, no responsibility is accepted by Kelly Regan for any wrongful information, omissions, or any other irregularities regarding any plan set or build article. This project is to be undertaken at the user's own risk. Kelly Regan accepts no responsibility for any injury to any person occurring while using or undertaking this project or any other related project, either directly or indirectly.