SVP-1284 + Power HD High-Torque Servo 1501MG =

Hi, this is my first time working with an Orangutan microcontroller and i’ve been thoroughly impressed with the functionality of the SVP-1284.

I’m working on a robotics project for university that involves interfacing with 2 ultrasonic sensors, controlling 2 motors, and controlling 2 servos.

The motors im using are these:
Key specs at 12 V: 350 RPM and 300 mA free-run, 110 oz-in (8 kg-cm) and 5 A stall.

The ultrasonic sensors i’m using are these:
Key Specs at 5V: 15 mA current consumption.

The servos i’m using are again from this website:
Key Specs: Unfortunately i wasnt able to find any information about current draw online

The whole setup is currently being powered from a 12V DC, 1.3Ah Lead-Acid (Rechargable) Battery.

On friday night I had one of the servos plugged in doing some tests under a heavy load. The setup was:
Fully charged battery powering the orangutan, which was controlling the servo (plugged into Servo 0 in the correct manner). No motors were plugged in and the controller was in an insulated box. A jumper connected Vcc to the positive power pins from Servo 0 - 3. It is my understanding that Vcc is regulated and capable of supplying up to 3 A.

I was running simple code telling the servo to change speed and move to various positions. Several times the servo would stall, and when trying to reset the controller, or turn it off, i had some problems, infact it seemed the power button wasnt responding!?

I finally managed to turn it off, but when i turned it on again the servo didnt move (as it had before) and instead after a short time the Toshiba Motor Controller IC closest to the blue power/motor terminal, the right one, flashed with a blue flame and emitted a strong smelling smoke.

What on earth is going on here? It has become apparently the motor driver has completely blown, which causes troubles when the robot is designed to have a differential drive (2 individually controlled motors).

How could a servo cause the motor controller to blow, and, was it even related to that?

Your help would really be appreciated!

Hi Max,

I’m sorry you have had trouble with our Orangutan robot controller. Your connections all sound good, and nothing immediately comes to mind that would explain what happened (and I haven’t heard of anything like this happening before). If the motor driver caught fire, it sounds like something was probably shorted somewhere in that area, though. Since you likely at least want the motor driver replaced, I think the next step would be for you to send it back to us to take a look at. Please email me at ben at pololu dot com (and include your original order number if you have it) and I will set you up with an RMA number.

- Ben