This Arduino based DIY is for everyone who would wants to run aeroplane ESCs with a surface radios. It goes in between the ESC and RX. Although, there is already an adapter called Pistix available in the market for the same purpose, I coundn't find any schematics or instructions about it to build one myself. With some help, I came up with something similar.

How the adapter works: An aeroplane ESC needs 0% throttle indication at startup, but since a surface radio throttle is set at about 25% by default, it makes the ESC beep as a warning to set the throttle to 0%. For the aeroplane ESC to work, you can either mechanically modify the Tx by setting the default position of the throttle to 0% or if that is not possible, you can do it the software way; the adapter takes the 25% signal coming from the Rx and remaps it to 0%, as an indication of 'no throttle' to the ESC.

Materials required:
1) ATmega8 or equivalent microcontroller- 1 nos
2) 16MHz crystal- 1 nos
3) 22pF ceramic capacitors- 2 nos
4) Servo extender- 1 nos
5) PCB

Additionally, you'll need an programmer to burn the code on to the ATmega8.
I used an Arduino UNO board for the same.

The Arduino code and the schematic can be downloaded from here-- https://www.dropbox.com/sh/anvf4ibo4hesyj1/0zflxkuvDT?m

Tested the adapter on my air boat, works flawlessly!
 
I used an ATmega8-16PU microcontroller for this project, couldn't get the code to run on an surface-mount ATtiny45-20PU, if some electronics genius on here can do that, it can physically reduce the size of the adapter to less than half.

I couldn't have done this project without help from lastrites (RCI member) and PeterH (Arduino forum)

 

After doing this, is it working 50% front and 50% reverse?

No, the ''reverse'' range on the throttle trigger is effectively eliminated by this circuit. Nothing happens when you throttle into reverse.

Thank you for the mention Anjan I agree the atmega8 is overkill for this application but the arduino is so darn easy to use

Hey Anjan try one thing. Use the arduino bootloader in this page: http://todbot.com/blog/2009/05/26/minimal-arduino-with-atmega8/
You will be able to get rid of the crystal and capacitors.

Sure, I'll try that.

I'm looking into miniaturizing it, ATtiny45 seems to have the most suitable specifications for the application, I managed to get a SMD type, but i'm having trouble with the code, I get too many errors on compilation and I don't know why?

Off topic but I could not resist Why "Why buy something when you can make it with half the features and twice the cost? DIY!! ". I have always found it out to be the other way round

No offence meant, however, after having used dozens of 'aeroplane' ESC's on my boats and hovercraft and not facing any trouble in operations/controls - I fail to  grasp and appreciate the utility of this mod/add on.

Oooopsie! I  now notice that you are talking about a Surface Radio with an Aeroplane ESC. I don't possess the former and therefore have no knowledge of its pre set throttle settings. I've been using the Air to Air combo (!) on my boats and craft, which in this case is makes my earlier post unnecessary.

Post no. 7 is now redundant. However, let it remain as a Boo Boo on my part.

Sorry!

Good for you, lastrites.

VC bhai, I thought boat modelers had a lot of patience and never overlooked the smallest details.

True, however, that depends on the time of day (or night!).