Photo 3. Close-up of the interface and DIN socket.
140. This produces the proper timing between frames. The
busy line is then sent high to indicate that the device is busy
and cannot receive data.
The buddy line is sent low for 500 microseconds and
high for a minimum of 365 microseconds. The remaining
high time is generated based on the channel data received
from the computer. The code then loops for every channel.
Figures 8A & B. Form for PC to R/C.
This tutorial provides the building blocks for much more
complex actions. By editing and adding on to the computer
GUI, much more complicated tasks — such as joystick control
and automation — can be achieved. Good luck and happy
78 SERVO 07.2004
for(c=0; c<numch; c++)
for(pwm_cnt=0; pwm_cnt<ch[c]; pwm_cnt++)
About the Authors
Keith Sevcik is an Undergraduate Student in Drexel
University's Mechanical Engineering Department in
Philadelphia, PA. He can be reached at firstname.lastname@example.org
Dr. Paul Oh is a Robotics Professor at Drexel University's
Mechanical Engineering Department. He can be
reached at email@example.com