Low-profile Mavic Pro Electronic Bait Drop

Description

This is a bait/payload release device for Mavic Pro, using the same LED-triggered electronics as Willem Jordaan's DJI Mavic Bait Drop: https://www.thingiverse.com/thing:3437969 (On the Mavic remote the C2 button can be programmed on the Mavic to turn the front LED's on/off, or if you start recording it will also turn the front LED's on. This is what triggers the release.) My lower-profile design requires no extensions to the drone legs (if launched from a flat surface), and can be printed without supports. There are 2 versions, depending on your battery size (9V or a 2S LiPo). The finished device simply clips onto the bottom of the drone and hooks over Mavic's battery retaining buttons - a rubber band or wire is still recommended on top for safety to keep it from coming off during flight. The photocell cover clips over the Mavic's front right LED and should be printed with 100% infill using opaque black filament (this cover might be useful even if you prefer Jorda04's original mechanism design). The main mechanism body can be printed with 10% infill to reduce weight. Electronic parts required are as follows (see original design): 1) Arduino Nano (or clone) with customized program to detect Mavic LED and turn servo (example program attached). 2) Photocell (mine was from an automatic nightlight). 3) 50K-100K ohm resistor. 4) Micro servo such as the Tower Pro SG90, with servo clevis link and a metal release pin (I used a snipped-off drapery pin). 5) Battery, wires, & connector. A 9V works, or use a small 2S 7.4V LiPo battery such as the Turnigy Nano-Tech 300mAh to save weight. 6) 7805 Voltage Regulator (or some diodes in series) for the servo (see note below). NOTE that the Arduino Nano's 5V regulator may have too much voltage drop to power the servo. An external voltage regulator is recommended for the servo only, otherwise the processor may lock up and/or cause the servo to jump to an unexpected position, especially if your input voltage is less than 9V. (If you use an external regulator, remember that you'll need to supply battery voltage to the servo during bench testing) You may want to modify the Arduino .ino code to configure the INPUT_VOLTAGE_HOLD/RELEASE values (depending on your photocell), and the SERVO_POSITION_HOLD/RELEASE values (depending on your servo and horn position). See comments in the .ino file. I was dissatisfied with the performance of the various wiggle-til-it-drops mechanisms and other mechanical payload release devices such as my own Mechanical Accelerometer Bait Drop https://www.thingiverse.com/thing:4332137. I created this using OpenSCAD. UPDATE 7/3/20: Added a circuit diagram for clarification.

Statistics

Category

Tags