Copyright © Parallax Inc.
ELEV-8 Flight Controller (#80204)
v1.2 1/4/2017 Page 5 of 10
ESC / Auxiliary Headers
The ESC and AUX headers have 0.1” pin spacing, oriented vertically. There are 6 ports, each with 5 V
power, GND, and bi-directional communication (see the Propeller I/O Pin Assignments on page 9). These
are typically connected to a standard ESC (Electronic Speed Controller) such as the Parallax xRotor 20A
ESC (#750-90015) included in the ELEV-8 v3 Quadcopter Kit.
The ESC ports could also be used to drive standard servos (such as a camera gimbal), provided that the
total current requirements of the servo motor are considered, and these external loads do not exceed the
maximum available on the Flight Controller (maximum 1.5 A total).
When configured for input, each I/O port is 5 V tolerant—equipped with a 10 k-ohm series resistor and
Schottky diode—and will typically sense high when the input voltage reaches 1.65 V. In output mode,
each I/O port can provide (source) up to 6 mA of current, and will typically be 3.3 V when high, and 0 V
when low.
The Parallax xRotor 20A ESC (#750-90015) is a non-BEC type (Non-Battery Eliminator Circuit), meaning it
does not contain a voltage regulator to provide 5 V power supply to the Flight Controller. This is fine,
because the Parallax Flight Controller has its own onboard 5 V power regulator.
The ESC and AUX ports signal (IO) pins are open. The Flight Controller does not have pullup or pulldown
resistors at these pins, so the user application is completely flexible to configure these pins as required.
The ESC and AUX headers can be re-assigned by editing the open-source Flight Controller firmware,
should you wish to interface with a gimbal, camera or proximity detector.
Piezospeaker
The piezospeaker is used to provide audible feedback of important events, such as arming, disarming and
low-battery conditions. Note that when the Flight Controller is powered only via a USB connection, the
piezospeaker may not be audible.
WARNING! The sound output from the piezospeaker is 60–80 dBA at
10 cm. Take appropriate precautions (such as using headphones or
ear plugs) when using the Flight Controller in close proximity, such as
during development or setup.
Power Input
The Power Input header, marked VIN, has 0.1” pin spacing, oriented horizontally. The board can be
powered from a voltage in the 6–18 VDC range. This voltage range is compatible with standard battery
packs comprised of 2, 3, 4, or 5 cells, and is compatible with lithium polymer batteries available from
Parallax (3300 mAh, #752-00010 and 5300 mAh, #752-00017).
