Gripper Test Script

Script

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.    

  • 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

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 Script Name was set to test_gripper_angles_buttons before saving it as a .hex file as shown in How to Save and Reopen a Script in Python Editor v2.

  • Plug the battery pack’s barrel plug into the cyber:bot board’s barrel jack.
  • Set the cyber:bot board’s PWR switch to 1.
  • Click Connect, then Flash.
  • Set the PWR switch to 0.
  • Disconnect the USB from the cyber:bot robot’s micro:bit module.

Test Script: # test_gripper_angles_buttons

# 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.