Gripper Test Script

Hardware Setup

• Set the cyber:bot board’s power (PWR) switch to Position 0.
• Make sure the battery holder is loaded with 5 AA batteries.
• Make sure the battery holder’s barrel plug is firmly plugged into the cyber:bot board’s barrel jack. 
• Connect your micro:bit module to your computer with a USB cable.

Software Setup

• In a Google Chrome or Microsoft Edge browser, go to python.microbit.org to open the micro:bit Python Editor.
• Right-click the test_gripper_angles_buttons.hex link below, choose Save As, and then save the file to your computer.

• test_gripper_angles_buttons.hex

• Open the saved test_gripper_angles_buttons file with the micro:bit Python Editor editor.

Note: The script was created by entering the python script below and adding the cyberbot.py module to the Project Files as shown in Add modules to your micro:bit.  The project name was set to test_gripper_angles_buttons before saving it as a .hex file as shown in Save & Edit Scripts.

Script: test_gripper_angles_buttons

The script will turn the Gripper’s standard servo to its 30° position. This will make the Gripper close and lift its paddles. Then it will turn the standard servo to its 150° position to make the Gripper paddles lower and open.  If your Gripper does not properly complete both motions, the troubleshooting section on the next page has a script you can run while making mechanical adjustments.    

• Make sure that you have completed the Hardware Setup and Software Setup tasks.
• Click Send to micro:bit.  
  (See Flash Scripts with Python Editor.)

# test_gripper_angles_buttons

from cyberbot import *

display.show(Image.ARROW_E)

while True:
    if button_b.was_pressed():
        bot(16).servo_angle(30)     # close gripper & lift
        display.show(Image.ARROW_W)
    elif button_a.was_pressed():
        bot(16).servo_angle(150)    # Lower gripper & open
        display.show(Image.ARROW_E)    

Tests

The main purpose of these tests is to verify that the script makes the Gripper complete both the close/lift and lower/open motions.  If it doesn’t do both correctly, try the Troubleshooting section on the next page.

• Set the PWR switch to 2.
• Press/release the micro:bit module’s B button and verify that the Gripper closes and lifts its paddles.

• Press/release the micro:bit module’s A button and verify that the Gripper lowers and opens its paddles.

• If the Gripper does not complete both the close-lift and the lower-open maneuvers, check the Troubleshooting section on the next page.
• When you are done, set the cyber:bot board’s PWR switch to 0.  To extend battery life, make sure to do this whenever the cyber:bot with Gripper is not in use.