User Manual

Software and Updates

If desired, the firmware may be upgraded and/or customized to enable or disable various features

such as complementary PWM, brake, RC-Car mode, or adjust default settings such as endpoints

and motor timing. The firmware can be updated using similar procedures as for the KK(2) and

other projects based on ATmega hardware. For source code, binaries, and other information, see

http://github.com/sim-/tgy/ and http://0x.ca/tgy/.

The easiest way of updating is with the Afro USB Linker from HobbyKing attached to the regular

PWM input cable. Only the signal and ground connections are required. The boot loader speaks

STK500v2 at 9600 baud using the half duplex protocol implemented by the Afro USB Linker. Other

linkers (such as USB serial linkers) will not work at this time.

The KKmulticopter Flash Tool or any general AVR ISP software may be used with any of the above

options. See the above URLs for links and more information.

Default Settings

Input control is available through PWM, or through I

C (MK) or UART with additional wiring (auto-

detected).

For PWM input, motor stop / arm below 1060µs, full power at 1860µs.

For I

C input, motor stop / arm at 0, start at 1, full power at 247. BL-Ctrl V2 reverse supported.

For UART input, motor stop / arm at 0, start at 1, full power at 200.

Low-voltage cut-off (input voltage checking) and temperature limiting are not enabled, as reacting

to such conditions on a multi-rotor will likely be worse than ignoring them. Always use a LiPo

battery alarm or telemetry to avoid over-discharging LiPo batteries!

General Operation

Once an input signal is received that is low enough to reach the “neutral” or power-off area, the

ESC will arm (long beep), and the green LED will light. Once the signal enters the motor start

range, the ESC will attempt to start or run the motor, and continue to do so as long as input signal

is above the neutral position. The amount of power used for starting is not fixed, just based on the

power requested, limited and ramped at first to increase the chances of a successful start.

In general, the power handling should be as smooth as possible, but not limited or filtered once

running. The default PWM frequency is 18kHz with 800 distinct steps, but may be adjusted to any

frequency. During starting, the PWM frequency is halved both to assist starting of some difficult

motors and as an audible indication of this state.

There is no latching of stopped or start states, as doing so could make acrobatic manoeuvres

unsafe. It should not ever be required to re-arm the ESC unless some signal, power, or hardware

fault occurs. In the event that an object (such as a tree) is struck by a moving propeller, the motor

will limit the power output until timing is regained, but not require re-arming. In the event that the

propeller is workable, this may permit a safer landing.

If a commutation time-out or long demagnetization period is detected, the red LED will light. This

should not occur in normal operation. Very brief flashes during rapid acceleration indicate that the

demagnetization period exceeded the expected zero-crossing point and that countermeasures

have been taken to avoid loss of synchronization. The green LED will remain off once running until

the power is turned off and the motor stops.

Throttle Range Calibration