DIY 6-DOF Robotic Arm with Bluetooth: Build & Program Guide

Description

Bluetooth robotic arm (OmArm Zero)

This is the Bluetooth version of the 6-DOF robotic arm. Same mechanical design, but now you can move every joint from your phone over an HC-05 Bluetooth module.

The arm has 5 rotational axes and a gripper, powered by MG996R and SG90 servo motors. A PCA9685 servo driver handles all the PWM signals, and an Arduino Uno runs the show. The HC-05 connects to the Uno’s serial pins and listens for movement commands sent from a Bluetooth terminal app on your phone.

How does the Bluetooth control work?

The Arduino code reads incoming serial data from the HC-05 and maps it to servo positions. You send a simple command string like “S1:90” to move servo 1 to 90 degrees. It is that straightforward. Any Bluetooth serial terminal app works. I tested with Serial Bluetooth Terminal on Android.

You can also hard code movement sequences in the Arduino sketch if you want the arm to run a routine without phone input. The code is commented, so editing it for your own use should not be a headache.

What is different from the basic version?

Mechanically, the arm is identical to the non-Bluetooth version. The difference is the added HC-05 module and the updated Arduino code. If you already built the basic arm, adding Bluetooth is a matter of wiring the HC-05 and uploading the new sketch. Takes about 20 minutes.

Printing and assembly

Same PLA settings as the basic arm: 0.2 mm layer height, 30% infill for structural parts. Total print time is around 15 to 20 hours. Assembly uses M3 hardware and does not require glue.

What’s included

• STL files for all printed parts
• Arduino code with Bluetooth serial control
• Wiring diagram and full parts list

Full tutorial: DIY 6-DOF Robotic Arm with Bluetooth Control