Build a 5-DOF ESP32 Servo Robot Arm for Under $25

What This ESP32 Servo Robot Arm Project Is

An ESP32 servo robot arm project is a low-cost, WiFi-enabled microcontroller robotics build that combines a mobile rover base with a 5-DOF servo arm so students and hobbyists can explore embedded systems, motor control, and basic programming through direct, browser-based control of multiple servos and a simple block-style sequencer. In this guide, you will build a DIY robot arm using an ESP32 DevKit, three MG996 servos, and four SG90 servos mounted on a small rover chassis. According to the project author on Hackster.io, “The estimated cost is around $25,” which helps keep this a budget robotics project that classrooms can afford. The ESP32 servo robot creates its own WiFi network, serves a web interface, and drives seven servos without extra hardware, making it an ideal platform for teaching microcontroller robotics fundamentals.

Parts, Cost and Why ESP32 Is Ideal

To build this 5-DOF servo arm rover, you need seven servos: three MG996 units and four SG90 micro servos. The ESP32 DevKit controls all servos with PWM and also provides integrated WiFi and Bluetooth, so no external communication module is needed. The original build lists approximate costs of USD 9 (approx. RM41.40) for three MG996 servos, USD 4 (approx. RM18.40) for four SG90 servos, and USD 3 (approx. RM13.80) for the ESP32 DevKit, with the full robot coming in “around $25” (approx. RM115) including power electronics and small hardware. A 2-cell 3.7 V battery pack in series or a single 18650 cell with a TP4056 charger powers a 6 V boost converter for the servo rail. With WiFi and a built-in web server, the ESP32 servo robot can be driven from any phone or laptop without installing an app, which suits crowded classrooms and workshops.

Mechanical Assembly of the Rover and 5-DOF Servo Arm

Begin your DIY robot arm by assembling the drivetrain. Mount two MG996 servos on the rear sides of the 3D printed base with M3 screws and nuts; these act as left and right drive motors. At the front, support a 3D printed wheel axis rod with a pair of 608 bearings and a bearing cover to form a simple three-wheel rover layout. Prepare all servo horns before final assembly, tapping SG90 horns with M2 screws and locking MG996 horns with M3 screws so the joints stay tight. Build the arm base next: mount the yaw servo in its bracket, back it up with two 608 bearings, then add the MG996 base pitch servo with a bearing on the opposite side for support. Attach the first arm section to this joint, then stack SG90 servos for shoulder, elbow, and wrist, ending with a claw servo and gripper. Test each joint by hand to confirm smooth, bind-free 5-DOF motion.

Wiring, Power and Flashing the ESP32

Place the ESP32 DevKit on the robot base with double-sided tape and position the battery, TP4056 charger module, and 6 V boost converter where they fit securely. Wire the battery to the boost input, then run the boost output as the 6 V servo rail. Connect every ground together: battery, boost converter, servo grounds, and ESP32 ground must share a common reference. Route the seven servo signal wires to the ESP32 GPIO pins used in the firmware: GPIO18 and GPIO19 for the left and right drivetrain, GPIO21 for the heavy arm joint, and GPIO22, GPIO23, GPIO25, and GPIO26 for the remaining arm joints. Do not power servos from the ESP32’s 3.3 V pin; use the boosted 6 V line to avoid brownouts. Flash the prebuilt firmware with esptool or build it using ESP-IDF, then power up the board to complete the ESP32 servo robot setup.

Controlling and Programming Your Budget Robotics Project

Once powered, the ESP32 creates an access point named ESP32-Robot-Arm. Connect to it from any phone or laptop, open http://192.168.4.1 in a browser, and you will see an interface for the rover and 5-DOF servo arm. One joystick controls the drivetrain, while the other and several sliders move the arm joints and claw, providing immediate feedback for students learning servo control and PWM. The “Program Your Robot” mode turns this ESP32 servo robot into a teaching tool for sequencing and logic: learners stack simple drive blocks to move the base and arm blocks to set servo angles, then press Go to execute the list. The design is open and forgiving, so frames can be printed, cut from cardboard, or made from scrap material, making microcontroller robotics accessible and low-risk for classrooms, makerspaces, and first-time builders.