This fork switches on all nFETs when the motor is idle (zero throttle). This is useful for gliders/planes to stop the prop from spinning with the airflow. See the following issue for more information :
This tree contains the BLHeli assembly code for sensorless brushless motor electronic speed control (ESC) boards. It was initially designed for use with Eflite mCP X, but is well suited for other copters/planes.
There is one version of the software for Silabs MCU based ESCs, and another for Atmel MCU based ESCs. Both versions are now at the same revision.
To view and use the files, click the "Download ZIP" button on this page and download the repository to your computer.
For flashing and configuration, download the BLHeliSuite PC software: https://www.mediafire.com/folder/dx6kfaasyo24l/BLHeliSuite
For more information, check out these threads:
http://www.helifreak.com/showthread.php?t=390517 (for SiLabs MCU based ESCs) http://www.rcgroups.com/forums/showthread.php?t=2136895
April 2012, Steffen Skaug