Remote Autonomous Droid or R.A.D. is a fully functional, 3D printed, DIY robot, based off of the Tri-Track SCAD version (https://www.thingiverse.com/thing:2832658). Light up 2 button controls allow for 4 base functions including 2.4ghz digital RC control, Autonomous roaming with Ultrasonic Object avoidance/audio investigative tracking, motor/sensor standby, and diagnostic serial readout. As an added feature I programmed in an RC override in the autonomous mode so at any time a user can take full control to prevent any accidents.
After I came across all of the Tri-Track style robot chassis on Thingiverse.com I had a strong desire to build a small robot platform based off of these designs. I started with the Tri-Track SCAD Version and TT Motor as I preferred the single part chassis as well as the cheaper hobby motor option. I imported these parts into Fusion 360 and started designing my own mounting parts to attach various common Arduino sensor modules.
As with any robot design the primary parts you need to factor into the rest of the design are always the drive system, motors, and power source. In this case I selected a T-1228A 12V 8000mAh rechargeable Lithium Ion battery pack as it had the correct amperage and fit snuggly in between the SCAD motor mounts. I drew up a power regulator mount for a standard LM2596S DC 3A step-down and then ended up using a second regulator to feed the motor controller directly.
There is a custom 3D printed circuit board (https://www.thingiverse.com/thing:3190898) that interfaces the Arduino I/O pins, power connections, headers for sensor connections, RC receiver, resistors for LEDs, Capacitors for motor filters, and an LM298N micro motor controller. These connections were hand soldered using 22G cat5E solid wire and a tight loop solder method. The object avoidance is handled by a single HC-SR04 Ultrasonic Sensor which is programmed to start an avoid function when an object is detected within 25cm of the robot’s forward path.
I wanted this little Bot to have some human interaction functions, so I integrated in 2 MAX9814 Microphone amplifier modules. Within the autonomous function (which I call Terminate Mode) the bot stops every few seconds and compares sound levels on either side of the head. Whichever side has the highest level of sound the robot starts driving towards.
My first design used a Foscam FI8909W for wireless video transmission from the bot. A Servo mount, servo arm and faceplate were designed to attach all sensors to the camera. I later designed a new head, servo mount, and servo arm for all sensors to all allow for easier build without requiring the camera. The new head design also allows the RC Receiver Board to be concealed within the head box.
R/C control is handled by a 2.4Ghz wireless receiver scrapped from a RC rover toy purchased at Walmart for $19.88 (New Bright RC Dune Tracker Stunt Buggy). This particular RC vehicle was selected because of its tank style steering and 2.5ghz digital controls. It is really exciting to see cheap RC toys from New Bright being sold with digital remote systems and the price is still pretty cheap. Make great hobby control setups with really good range.
I have included all .stl files created by me, a wiring diagram, and my latest version of the full Arduino .ino robot OS.
Hope you enjoy,