Mini maestro and animatronics

Hello Folks, I am a physics teacher with a small charter high school on Marco Island FL. We has a Christmas Parade and we 3d printed little circular discs to hold a ginger bread house together with 4 LEDs embedded in each disc. We then programmed the lights to blink in time with Christmas music. It worked, however it was very dim. I powered the maestro independently by using a 12v source. The maestro dropped the voltage to 5v output and the LEDs were really dim. (All LEDs were wired in parallel). I ended up using a VEX battery pack with a buck converter to drop the output to 3.75 V and brightly light the same LEDs.

Is there a better recommendation to mass animate servos and LEDs?

It sounds like you are using the Maestro’s channels as digital outputs (which are 5V) to control your LEDs. The signals lines on the Maestro cannot provide much current, so there is no good way to increase the brightness of any LEDs controlled by them. You might consider adding MOSFETs for each digital output channel you are using, which would allow you to turn on and off external power to the LEDs, like from your 12V source. Alternatively, you could change the Mode of the channels you are using to control LEDs from Output to Servo and use something like this RC switch to accomplish the same thing.


Jonathan, so the servo output could be sent to the RC switch so that I can
use the low control voltage to control a higher voltage that would be sent
to the LEDs. Wouldn’t this be a binary solution? Only on or off, no
dimming? Could I also use a Pololu G2 High-Power Motor Driver 18v25. Or
something smaller driven from the pwm pins on the maestro?

And, I have another problem that this might solve. I have a team of
students building an underwater ROV. I have several very nice RC Motor
Controllers that are waterproof. They are high voltage/high power units
but I cannot talk to them using an Arduino. Would this give me the ability
to send my PWM output from the arduino to control my brushed dc motors. My
current solution is to use one Pololu G2 High-Power Motor Driver 18v25 per
motor. What I have WORKS, but it is not waterproof. Could I use one of
these RC switches to talk to the RC ESC?

Frank Wood
Instructor Chemistry, Physics, and Engineering

Coach Ray-Bots Underwater Robotics
Sponsor STEM Club
2255 San Marco Rd., Marco Island, FL 34145 (239) 393-5133

Yes, the RC switch I mentioned is only appropriate for turning an LED off and on; it is not appropriate for dimming an LED. However, you can use motor drivers like the G2 18v25 to do that. Like you suggested, you could configure a PWM output channel on your Mini Maestro and connect that to the PWM input on the motor driver.

As for your other question, none of our boards (including the RC switches) are waterproof.