Servos won't move

[FTC9387]

Hello, we are trying to program the servos, and they won't move. We are programming with the MIT App Inventor and are using the Matrix motor and servo controller. The motors run fine, but we can't get the servos to move. We are using the exact code that is in the FIRST training for servos. We have tried several different servos. Nothing. Does anyone know what could be wrong?

[eharwood6311]

Team FTC9387


Good morning. Here is our example of working servo control. We are using 2 servo's for a robotic gripper function.


If the driver presses the A button:
Right.servo.position = 1 , right servo will close
Left.servo.position = 0, left servo will close


If the driver presses the X button:
Right.servo.position = 0 ; right servo will open
Left.servo.position = 1 ; left servo will open.


To achieve these values, our team first worked on one servo, say the right servo, to understand what the values were for open/close. They repeated the process for the left servo motor. They were able to create the above table of position values to get their gripper to work properly.


Here is the code our team is using:

https://drive.google.com/file/d/0ByWH7P37ddH7eHBnSEtDNUpvWHc/view?usp=sharing

Hope it helps..

Eric
Team# FTC9977

[skatefriday]

Hello, we are trying to program the servos, and they won't move. We are programming with the MIT App Inventor and are using the Matrix motor and servo controller. The motors run fine, but we can't get the servos to move. We are using the exact code that is in the FIRST training for servos. We have tried several different servos. Nothing. Does anyone know what could be wrong?

I don't have any experience with App Inventor, but you must enable
the servos prior to using them, as they default in the pwmDisable state.

In java this would be calling the pwmEnable() method on the ServoController.

[Comrade 17]

In App Inventor, the FtcServoController component has a PwmEnable block.

[BSV]

Another possibility is a bad control module. We've had two DOA controllers. One of them lit up and could be seen by the phone, but didn't output a signal to control anything.

You can download the Core Device Discovery program to make sure it's not an electronics problem:

http://modernroboticsinc.com/coredevicediscovery

[bassamali01]

Another possibility is a bad control module. We've had two DOA controllers. One of them lit up and could be seen by the phone, but didn't output a signal to control anything.

You can download the Core Device Discovery program to make sure it's not an electronics problem:

http://modernroboticsinc.com/coredevicediscovery

Ooh.. I never knew about that!

[schaferbw]

Another possibility is a bad control module. We've had two DOA controllers. One of them lit up and could be seen by the phone, but didn't output a signal to control anything.

You can download the Core Device Discovery program to make sure it's not an electronics problem:

http://modernroboticsinc.com/coredevicediscovery

I downloaded the users guide and Windows app from this page. Norton was suspicious of the app because it found the number of Norton users with the file low given that the file was two months old so it quarantined the file. I overrode the quarantine and invoked the application on my Windows 7 laptop. I cabled the Core Power Distribution Module to one of the USB ports on my laptop and turned on the robot's power via the switch on the Distribution Module. It took a very long time to install the driver but eventually did so successfully. The application seems to be working fine and should be quite useful.