Petoi Bittle Manual

5 🔌 Connect Wires

"Everything is connected." 🤝

5.1 Servo wiring


Connect the wires of servos to the NyBoard servo pins as below. They follow a circular symmetry. Notice the skipped indexes between the head and leg servos (1~7). They are reserved for our future robots with more joints.
Observe the wiring pattern on the board
The index number of the joint servo has no corresponding relationship with the PWM pin number on the main board. You don't even need to read the pin numbers on the PCB board.
The black wire (GND wire) should be closer to the board.
Bottom view:
Inserts the infrared receiver under the back plate so that the sensor can expose to the outside.
Make sure that the wires go into the body, bypass the columns, then plug into the servo pins. Arrange the wires so they don't get in between the servo plugs and the body frame. NyBoard should be leveled on the four standoffs. Use four M2x8 self-tapping screws to fix the NyBoard.


Although the BiBoard has only 12 pins, the joint index numbers are configured in the same order as the NyBoard. The connection between the joint servo and the pin is shown in the figure below:

5.2 Prepare for calibration

When calibrating, you need to install the head and leg components on the gear of the output shaft of the servo. No screws are needed, but you must enter the calibration mode before installation.
There are five methods to enter the calibration state:
  • long-press the battery and boot up the robot with one side up. It will enter the calibration state automatically. The picture below shows the upper legs and lower legs installed after the robot enters the calibration state.
  • Use the mobile app Petoi to enter the calibration panel.
  • Use Joint Calibrator in Petoi Desktop App :
    • If you have already connected the robot and computer with a serial port, It will enter the calibration state automatically when you click the " Joint Calibrator" button
    • Click the "Calibrate" button in the calibrator interface
  • In the serial monitor of Arduino IDE, enter the serial command "c"
  • Press the calibrating button
    (3,3 - the 3rd row and 3rd column) on the infrared remote.

Install the head

In the calibrated neutral state, place the head as close to the central axis as possible and insert its servo shaft into the servo arm of the neck.
Press down on the head so it is firmly attached to the neck.

Install the legs

Install upper leg and lower leg components to the output teeth of the servos when the Bittle is powered on and in the calibrated neutral position. Please keep the torso, upper leg, and lower leg installed vertically as much as possible, and do not install the lower leg backward, as shown in the picture.
Measurement and installation can be carried out with the aid of a triangle ruler or the L-shaped ruler included in the kit.