DIY – xESC Adapter [Ver2.0 w/ATtiny45]

Back in October 2013, I made an Arduino based adapter that allows unidirectional aeroplane ESCs to work with surface/pistol radios for RC cars and boats. I used a ATmega8 microcontroller in that adapter and honestly, that by itself was the size of an average ESC, I couldn’t really put it anywhere conveniently on my car due to space constraints and weight concerns (If I can cut down on 5g, believe me, I will).

Even back then, I was trying to make the code work on an ATtiny45 and I wasn’t sure what was going wrong until, Justblair pointed out in the comments that the Tiny45  doesn’t have 16-bit timers, only 8-bit ones and my code was based on the Arduino servo library which utilized 16-bit timers. He also suggested a solution to get my code working on a Tiny45 and that fix is the Servo8Bit library.

DIY- xESC Adapter [Ver1.0 w/ATmega8]

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 couldn’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 a 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 Trishit Ghatak and PeterH (Arduino forum)