PySTEM Mini Bot Assembly Guide

Step by step instructions to build your own robot

Required Tools

Required Parts

Assembly Steps

1. Install Magnetic Bead as Omni Wheel

Use a 30mm screw to go through the ball mount.

Insert screw into ball mount

Press fit the magnetic bead into the ball mount

Press fit magnetic bead

Secure the ball mount on the chassis

Secure ball mount

2. Mount MPU-6050 Module

Fasten 2 12mm screws on the servo cover to mount the MPU-6050.

Insert mounting screws

Place the MPU-6050 with 1.8mm spacers to protect the resistor when fastening.

Place MPU-6050 with spacers

Fasten the MPU-6050 on the servo cover

Fasten MPU-6050

Connect the 4-pin dupont wire to MPU-6050, following the color coding exactly.

Connect MPU-6050 wires

3. Install Continuous Servos and Wheels

Insert 3 20mm screws through the holes on one side of the chassis

Insert chassis screws

Attach the wheel cover with nuts, keeping them loose for easy wheel installation later.

Attach wheel cover

Snap the wheels onto the continuous servo and fasten the screws.

Attach wheels to servo

Attach the speed encoder mount to the wheels and place the encoder disk on the mount.

Install encoder disk

Assemble the continuous servo with wheel and encoder disk onto the chassis, then tighten the wheel cover screws.

Install servo assembly

Repeat these steps to install the second continuous servo and wheel on the other side.

Second servo installation

4. Install Line Sensors

Put the servo cover on and fasten with 20mm screws.

Install servo cover

Install sensors and switch

Use 30mm screws to fasten speed encoders. Connect dupont wire following the colored order.

Install speed encoders

Use a 25mm screw to fasten the IR reflective sensor. Connect dupont wire following the colored order.

Install IR reflective sensor

Route all wires through the middle hole to the flat side of the chassis.

Route wires through chassis

Snap the button switch onto the chassis top. Use a thin stripe of tape to make sure it fits tightly. Connect the dupont wire following the colored order.

Install button switch

5. Install ESP32 Board

Insert 3 12mm screws from the bottom of the chassis through to the top. Add 3.5mm spacers to raise the board.

Install board mounting screws

Place the ESP32 board and secure it with nuts

Secure ESP32 board

6. Connect Wires

Connect the servo wires:

  • Top servo wire to pin 16
  • Bottom servo wire to pin 17

Be sure to follow the color coding exactly.

Connect servo wires

Connect the encoder wires:

  • Top encoder wire to pin 13
  • Bottom encoder wire to pin 14

Ensure proper color coding.

Connect encoder wires

Connect the remaining components:

  • MPU-6050 wire to pin H13
  • IR reflective sensor wire to pin 32
  • Button switch wire to pin 26

Follow the color coding exactly for all connections.

Connect remaining components

7. Install Top Covers

Insert 4 45mm screws through the top cover holes. Two of these screws will also secure the battery cover.

Insert cover screws

Secure the top cover to the chassis

Attach top cover

Use two 10mm screws to secure the remaining holes of the battery cover

Secure battery cover

Install the battery box and connect the power plug to the ESP32 board. Do not turn on the power yet.

Install battery box

8. Final Inspection and Testing

  1. Double check that all screws are properly fastened
  2. Verify all wire connections and color coding
  3. Place the robot car on the ground
  4. Turn on the power
  5. Press the button switch

Success Criteria

The robot car should move in a straight line. If it doesn't:

  1. Turn off the power immediately
  2. Check all wire connections
  3. Verify color coding of all connections
  4. Ensure all components are properly mounted