Robot Arm

Bittle can be equipped with a robotic arm, which we will call it Bittle X+Arm. This robotic arm gripper has more functions than Bittle and can perform more complex skills, such as grabbing objects for display or moving them to different places.

When the robot arm is in motion, please do not put your hands between the robot claws to avoid being pinched.

Installation

You must use the neck part with a J-hook (as pictured below) to use this robot arm.

This robot arm is already fully assembled. You need to install the servo with the neck structure in the servo slot with two M2*5 self-tapping screws.

Upload the firmware

In the Petoi Desktop App, choose the model Bittle X+Arm, then click the Firmware Uploader button to upload the firmware for the robot with an arm.

Joint Calibration

The robot arm must be finely calibrated to make it more precise when performing actions and to prevent the robot claw from jamming and overheating.

You can use the Petoi Desktop App to calibrate it.

Prepare for calibration

You must connect the motherboard to the computer via a USB data cable or Bluetooth wireless.

Then, install the battery and long-press the button on the battery to power the robot.

Enter the calibration state

After the robot is powered on, there are two methods to enter the calibration state:

• It will enter the calibration state automatically when you click the Joint Calibrator button.

  
• Click the Calibrate button in the calibrator interface.

BiBoard_V1_*

BiBoard_V0_*

The servo slider is not available in the interface's light yellow background area.

Fine calibration

Click the corresponding slider track of the robot arm and adjust the robot arm by calibrating the posture as shown below：

The joint index corresponding to the claw is 2. It can be auto-calibrated by pressing the Auto button or inputting the serial command "c-2" on the serial monitor of Arduino IDE. You can also manually click the corresponding slider track and adjust the gear on the servo output shaft to the position shown in the figure above.

How to use

Voice command

The robot program defaults to voice mode. Before controlling the robotic arm with voice commands, you must say "Start learning" to activate the custom voice command mode. Then, follow the voice prompts to record your voice commands in the following order to call predefined skill actions:

1. "Learn skill"

2. "Play skill"

3. "Follow"

4. "Pick up"

5. "Put it down"

6. "Hunt"

7. "Show off the object"

8. "Put away"

9. "Throw away"

10. "Shoot"

Once you have finished recording your voice commands, say "Stop learning" to exit the custom voice command mode.

The meaning of the voice commands:

"Learn skill": This command de-energizes the robot servos, enabling continuous manipulation of the robot's body pose for skill motion capture.

"Play skill": This command allows for the playback of the captured skill motion.

"Follow": This command de-energizes the robot servos, enabling you to manipulate any leg, with the other legs copying its motion.

"Pick up": To pick up the object.

"Put it down": To put the object down.

"Hunt": To grab the object quickly.

"Show off the object": To show off the object.

"Put away": To put away the object.

"Throw away": To throw the object aside.

"Shoot": To throw the object forward.

Mind+

You can use the Perform robot arm skill block in the Petoi Coding Blocks to do some pre-defined skills.

For example:

Serial command

After connecting the motherboard to the computer via a USB data cable or Bluetooth wireless, you can use the following commands in the Arduino IDE serial monitor.

  "kpickD",      // Pick up the object under the robotic arm.
  "kpickF",      // Pick up the object in front of the robotic arm.
  "kpickL",      // Pick up the object to the left of the robotic arm.
  "kpickR",      // Pick up the object to the right of the robotic arm.
  "kputD",       // Place the grasped object under the robotic arm.
  "kputF",       // Place the grasped object in front of the robotic arm.
  "kputL",       // Place the grasped object to the left of the robotic arm.
  "kputR",       // Place the grasped object to the right of the robotic arm.
  "klaunch",     // Launch the grasped object forward.
  "ktossF",      // Throw the grasped object forward.
  "ktossL",      // Throw the grasped object to the left.
  "ktossR",      // Throw the grasped object to the right.
  "khunt",       // Quickly grasp the object in front.
  "kshowOff",    // Show the grasped object.
  "kclap",       // Make a clapping motion with the robotic gripper.

Skill and directional combinations

Skill Name	Front	Left	Right	Down
pick	pickF	pickL	pickR	pickD
drop	dropF	dropL	dropR	dropD
put	putF	putL	putR	putD
toss	tossF	tossL	tossR	tossD = launch
hunt
showOff
clap

Note: When using the serial port commands in the table, you need to prepend a lowercase English letter "k", for example, "kpick", "kpickF". When using serial port commands that do not end with a directional character ("F", "L", "R", "D"), such as "kpick", the robot will randomly execute any one of the four directional actions corresponding to this skill.

Advanced Usage

Create new skill

You can use the Skill Composer in the Petoi Desktop App to create new skills for the robot arm and export them to the mobile app, the Mind+ program, or the source code.

Extensional application

This robot arm can be used in combination with other sensors. The installation method is shown in the figure below. e.g., adding the Grove Vision AI V2 module:

The source code also needs to be modified. The sample demo code is being written, so stay tuned.