closed loop. Size of a BASIC Stamp
board. Programs in C using free
Code Warrior compiler. There is no
USB or RS-232 on the chip.
Programming requires chip to be
connected to a development board,
then placed on the final circuit card
that will fit in the robot. The
alternative in-circuit programming
requires additional hardware, and I
would buy that if I were to work
with this chip more. I liked the
compiler and the chip is powerful.
3. DigiMix3 from Firmtronics;
made analog closed loop. This looks
like a real small mixer with R/C
cables for input and output. There is
no soldering iron required for this
one. It comes with three R/C input
cables and two output headers
(pins) for standard R/C connection.
One of the inputs can be used for
analog input. It has preprogrammed
standard mixer functions that can be
downloaded with the provided
program adapter and software. It is
also customizable; I made it a true
closed loop. It is an Atmel AVR
processor. The programming is C
using the free Programmer’s
Notepad — a component of the AVR
4. Arduino Nano; made into a
digital up/down limit and closed
loop. Size of a BASIC Stamp board.
Drives a Victor 883. Again, an AVR
microcontroller. Programmed in C
with the free Arduino
compiler/downloader. The USB
driver chips are on the Nano. I cut
up a piece of prototype board,
soldered R/C cables, and trim pots.
In an hour, I was downloading and
Photo 3. Single-turn
potentiometer on output shaft.
The next few are controllers
with included motor drivers,
replacing the Victor 883.
Photo 4. Multi-turn
potentiometer mounted to motor.
5. MotionMind from Solutions
Cubed. It does not require
programming. I configured it closed
loop with the provided software.
The motion of the stick is followed
by the motor. Connected to the
throttle, it will stay where you put it.
It works very well but it is much
smaller current capacity, compared
to the Victor. I was not able to drive
a HF 18V with it. Would be a good
fit to a beetle or some other smaller
6. AX1500 from RobotEQ. Equal
in capacity to a Victor when the two
channels are slaved together.
Configured with supplied software
to various programmed options; I
picked closed loop. At power up, the
lifter moves some before settling
down. This makes passing safety a
problem. I added a RCE210 relay to
the motor output’s connected gear
channel. This way, failsafe and
power-on is done with the gear
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