I've been working on this project for a while and I'm finally ready to share it with the control line community.  Don't get your hopes up, it's not a fancy, sensor laden, super fantastic CLPA timer.  (Although it's a good starting point.)  The target user is a new or returning control line flyer that wants to get started with electric power.  It should be sufficient for the average sport flyer as well.

The availability and cost of a good basic timer has sometimes been a challenge.  A while back I converted a Flite Test Mighty Mini to use as a control line trainer and was surprised to find the timer was the single most expensive item on the BOM.  When I researched the electronics hobbyist sites I was amazed at the variety of new and powerful micro-controller development boards and sensors available.  So, I bought a few and started experimenting.  I'm definitely not an senior embedded system engineer nor a crack programmer.  I'm just a techy OG with a desire to make a better mouse trap.  My code may be a bit of a brute force attempt, no fancy OOP here, the bottom line is, it works!

I call it the Touch_and_Go timer and I hope a lot of flyers try it out.  The program code is a free download and yours to modify as you see fit.  The hardware costs $8.95US and is distributed all over the world and is available from numerous local online vendors.  No expensive shipping and duties to worry about.  There is a bit of soldering of pins involved to complete the assembly.  The manufacturer of the board has made it super easy to program.  If you can copy and paste a file, you can program the board.  No other complicated software to download and install.  Simple code changes can be done using a text editor already on your computer.

I tried to include as many features as possible.  It's small and lightweight, field programmable (without any additional tools, boards, boxes or laptops) and usable with inexpensive ESC's.  While there is no direct RPM feedback, it does boost the RPM to compensate for decreasing battery voltage over the course of the flight.  One of the pins is set-up as a capacitive touch sensor which is used for operator input.  A multi-colour LED is used as output, indicating the status of the timer.

I put a lot of effort into making it as easy as possible for anyone to make their own.  Please make one of these 'do-it-yourself' timers and let me know how you make out and tell me what you think.  I set it up as a GitHub project, if you are familiar with that (not a requirement). 

All of the details can be found on my webpage: https://circuitflyer.com  At the bottom of the page is a link to a PDF file for the complete instructions (I've also attached it here).  The program code can be dowloaded from a button at the top of the webpage.

There you go, folks.  Take it from here and see where this open source project leads.  I hope it promotes at least a few new electric control line flyers.

Paul

  I would love to try one of these, just for the sake of making one because I like to tinker with this stuff. Can the program be modified to use a better ESC such as a Castle that I can set up in Governor mode or in set RPM mode? I think this would require doing away with the compensation setting and making it one setting across the whole flight time.(Would this be a complicated programming mod?)  Hopefully I explained this right as I know nothing about programming and I'm not an engineer, just a hobbyist that's not afraid to tinker and learn. I also have a few castle ESC's and would prefer to use what I already have and use it in Governor mode. I also have no interest in the "cheaper esc's" that are available. Like I've written many times before on here and in other places, used and NIP  Castle ESC's  can often be found on eBay and rc forums for a fraction of their original cost and many times for less than the cost of the so called "cheap ESC's".

I've used a KR timer on a Castle ESC . I've also used the castle ESC extensively with Hubin timers and tried it with Fieoretti timers and even a z tron timer,so I know it works with all of those. 

No, only the M0 will work.  It has a lot more memory and is faster.  Checking online, both digikey.ca and mouser.ca have over 500 of the M0 Trinkets in stock.

Paul

Wiliam all ESC will work with the RC stile signal. The incompatibility part is in the way they are armed. Some want full throttle then idle to arm others like any throttle set then idle for some time to arm etc. If you know what you have and how it arms then check the "sketch" and adjust a little.

Glad to hear things went well.  I've heard back from a few people that have assembled and flown the timer.  All are quite happy with it and haven't had any issues. 

It is tiny.  With my old eyes I have to make sure I don't burn my nose with the soldering iron.

Paul

Got one a few weeks ago, less than 10 beer tokens delivered, 10 minutes to solder, 10 minutes to learn how to operate it.

First flights yesterday, worked perfectly. Set 30 seconds pause (reduced to 20) with 1 minute run time to do some trimming flights. Three flights, zero problems, does exactly what it says on the can cheap and easy.

Paul

Dwayne,

Haha, my secret cyber identity.  Ya, I beat you in old time with my rectric ringmaster, remember?

Paul

Yeah I remember, hey Paul...lol

Hi Paul,

I have been flying ic control line planes since 1960 and now I am going to electric flight. I have an E-flight 25 and two 1.8 Turnigy 1800 mah 3 cell 11.1v Li-po Batteries. I intend to build a plane that was for a .25 engine. Now I need a timer to start and stop the motor. Where/how do I get your timer?

Thanks for your help,

Roger

Please please please start a new thread with this question, in this section.  I really want to help you out, but I really don't want to participate in a thread hijacking.

I think CircuitFlyer's idea for this timer is that you do it yourself from readily available parts.

If you want to just buy a timer that'll work well for you at this stage of your development in electric, I'd suggest either a KR timer from Brodak, or a Hubin timer, for which I think you need to apply to Will Hubin -- but you can search the member list for "Hubin" and send him a PM (or someone here knows where you can get Hubin timers and will correct me).

Hi Paul,

I went to Adafruit.com and I have no idea what to ask for. I want to make your timer but I need more information. Does the circuit board have a part number or something to identify the exact one to make the timer?

Thanks,

Roger

Roger:

The photo for the Teensy 3500 certainly implies that you get a strip of header pins with it -- Paul can confirm that, though.

The Adafruit name for these is "0.1 inch male headers".  If the 3500 doesn't come with that strip that they show, then you want these, from Adafruit: https://www.adafruit.com/product/400.

Paul:

Any time I find someone confused by my directions, I edit them and post an updated version.  And yes, that's a hint.

I ordered my board today and inspected the code.  I usually do my microcontroller work using Atmel Studio  and WinAVR in C ... but the Python stuff looks easy enough to learn if I decide I want to re-program it.

Paul,

Does Adafruite industries have a board that will work as an ESC?

Thanks,
Roger