The RapidESC initiative was started to give an honest source of information regarding pre-made and re-flashed ESCs that are modified for extremely high performance on MultiCopters.
The OpenPilot Team and developers such as Simon Kirby have been working hard to create Open Source firmware that offers the Rapid ESC response performance which greatly enhances multirotor performance.
What is RapidESC?
So, what exactly is RapidESC and why do I need it?
Standard ESCs are actually not designed for multirotor applications. They are programmed to increase and decrease the throttle command towards the motor in a gentle way. The reason for this is quite obvious. Imagine a motor accelerating and decelerating so abruptly in a helicopter or car... it would damage the gears and reductions in no time. In a multirotor application, we really want just the opposite. The goal is to change the motor speed, and thus the thrust, as fast as possible to achieve a perfectly stable platform.
While the current ESCs used in most multrotor applications work considerably well, there is a lot of room for improvement. Using the same ESC, but loading it with dedicated optimized software, will increase the handling and stability of your multirotor greatly.
We call this RapidESC: converting your regular lazy ESC into a high speed capable speed controller at no extra cost, ready for multirotor applications.
In the below movie you can clearly see the advantage of a RapidESC vs an ESC with stock firmware.
How is it done?
The process is popularly called flashing. It's actually quite similar to the firmware update from the OpenPilot product through the USB cable and the Ground Control Software.
The ESC must be connected to the computer via an interface adapter. Afterwards, new software is installed onto the ESC via your computer. Unfortunately, the ESC is not equipped with a standard USB connection port. nor was it intended to be upgraded by the user, so a few little tricks are needed to upgrade the software. This document will illustrate how to successfully upgrade your ESC.
Please note that there is always a possibility you will damage your ESC. Loading the wrong firmware may damage your ESC permanently.
The upgrade should be done at your own risk.
The first step is to check whether your ESC can actually be upgraded. At the time of ths writing, only ESCs with an ATMEL micro controller can be upgraded. ESCs equipped with a SiLabs micro controller, which are mainly recent HobbyWing ESCs, cannot currently be upgraded.
Close up from a Hobbyking 18A ESC with a Atmel micro controller.
An ESC with this version of MCU can normally be upgraded.
Close up from a Hobbywing 6A ESC with a SiLabs micro controller.
An ESC with this version of MCU is typically accompanied with 4 contacts or programming points and cannot be upgraded.
Please note that the latest Hobbywing ESCs are no longer sold with an Atmega microprocessor. While earlier versions of these ESCs are equipped with an Atmga MCU and can be upgraded, newer versions cannot be upgraded. The only way of knowing if you have an Atmel processor on your ESC is removing the protective heat shrink and verifying the MCU type. If the MCU is an Atmel like in the above noted picture, then it should be possible to upgrade the ESC.
Check your ESC
The only way to check whether your ESC is compatible and flash new firmware is to remove the protection. Caution here... you can damage the components on the ESC if you are not careful. In the following slideshow an X-acto knife is used to cut the protective shrink tube. Carefully cut along the side of the PCB and do not damage the components.
The micro controller should be an Atmel controller, it is regularly accompanied with 6 contact points, but this is not necessarily a requirement.