SunFounder PiArm, Manual, Page: 133 / 163

Piarm, Release 1.0
(continued from previous page)
print (manual)
while True :
key = readchar() . lower()
control(key)
if key == chr ( 27 ):
break
In this code, the
control()
function is created to control the PiArm by reading the key values on the keyboard.
•
alpha
,
beta
and
gamma
refer to the angles of the 3 servos on the arm respectively, refer to: Angle Mode .
• Press the
w
key on the keyboard, the
alpha
increases and the Arm will extend forward.
• Press the
s
key on the keyboard, the
alpha
decreases and the Arm will retract backward.
• Press the
a
key on the keyboard, the
gamma
increases and the Arm will turn left.
• Press the d key on the keyboard, the gamma decreases and the Arm will turn right.
• Press the i key on the keyboard, the beta increases and the Arm will raise up.
• Press the
k
key on the keyboard, the
beta
decreases and the Arm will lower down.
• Finally, use the
k
and
l
keys to control the ON and OFF of the Electromagnet respectively.
4.6 Coordinate Mode
PiArm’s arm has 2 control modes: Angle Mode and Coordinate Mode .
• Angle Mode : Write a certain angle to the 3 servos of the arm to make the arm reach a specific position.
• Coordinate Mode : Create a spatial coordinate system for the arm, set a control point, and write 3D coordinates
to this control point to make the arm reach a specific position.
The Coordinate Mode is used in this project.
This project sets 2 coordinate points by coordinate mode, and let the PiArm clip the rubber duck on the left to the bowl
on the right. But you need to mount
Hanging Clip to the PiArm first.
4.6. Coordinate Mode 129