Your robotic problems solved here.
shown in red on the bottom of the program window.
Carefully examine the cables that run to the servos noted
by the program. Let me know how it comes out.
Q. I have a Bioloid Premium robot that I built into the “Type A” walker that uses 18 servos. I built it with the gyro installed; my kit uses the CM530
controller. This robot has been working for months, but
recently started doing strange things. Sometimes when I
turn it on, it repeats a three-note sequence over and over.
It will not respond to commands in this mode. Sometimes
it starts up normally, but the legs turn pigeon toed and
the arms are in the wrong place. It will then tie itself into
knots if I try to give it any move commands. Sometimes it
starts sounding a low note, repeating it in time to LEDs
blinking on the hip servos. I’ve looked at all my cables
and even restored the firmware and motion files.
However, I can’t get the task file to download anymore.
I’m am super confused! Help me!
A. I thought that my Google-foo would answer this question quickly. Eh, not so much. Rather, it did eventually help me
find the answer, but I had to contact Bioloid
technical support and get help from some
online retailers that sell the Bioloid. Regardless,
I found the answer! Our first step is to consult
the CM530 guide which can be found at
This by itself doesn’t help us much, but it allows
us to see that the CM530 is a lot like the CM510, whose
Premium e-manual page is at http://support.robotis.com
This e-manual shows the
various types of robot you can build
with the Premium kit. More
importantly, about two-thirds of the
way down the “page” there are
some troubleshooting hints. Your
issue is almost certainly this one:
“The robot type and melody do not
match.” (“Huh?”) Look at the Type
A row and the Do Re Mi column
where it says “Check cables for
ID7-8.” You said that your robot
got pigeon toed on startup. These
two servos control the hip action
that turns the legs. The Bioloid
support team suggested that I use
the Dynamixel Wizard to look for
bad connections to the CM530.
In the July 2013 Mr. Roboto
column, I wrote about an Arduino library I created to use
Dynamixel servos. In that, I created an interface board
(Figure 3) that connects to the Bioloid USB2Dynamixel
device. Remember, you need to
power the servos from an external
battery; see that article for details.
To use the USB2Dynamixel, you
connect your three-pin connector
(with the V+ wire removed) to the
connector on the side of the
USB2Dynamixel unit. Don’t
connect your battery yet. On the
other side, move the slide-switch to
the TTL position (see Figure 4).
Disconnect one side of your “legs”
cable from the CM530 as shown in
Figure 5. You do this so that you
don’t power your CM530 up from
the external battery through the
Now, find an open servo port
on one of your servos as I did in
the ankle shown in Figure 6. What
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