Get the Encoder Data from NI Robotics Starter Kit 1.0

[Mashfique]

I want to make a perfect 90 degree turn using the encoder Data from Robotics Starter Kit 1.0. Now I am doing it giving the angular velocity and controlling the time. But, the problem is, it's not perfect all the time. It is not repeatable. So, I want to use the encoder Data to turn it 90 degrees perfectly. So, How could I get the Quadrate Encoder Data from the motors (What VI should be used?). 

[Philosophe]

Do you have any hardware hooked up to your system?

[Mashfique]

Hi Philosphe,

I am using NI Robotics Starterkit 1.0.It has a sbRIO 9631 with it and  a sonar sensor attached with it. There is no other hardware that is connected to my system. 

Thank you.

[RyanPoPo]

Hey Mashfique,

Rather than using angular velocity and time, it may be a better approach to just read the angular position and increment and decrement the rotation to reach 90 degrees. You can read the angular position using the Maxon Encoder Read located in Functions >> Robotics >> Sensors and Actuators > Device I/O >> Encoders >> Maxon Encoder >> Data >> Read.

Regards,

Ryan

[Mashfique]

Hello Ryan,

Thank you for the suggestion. I have tried it. But currently I don't know which pins are connected to the encoders. Is there any way that I could figure it out without checking the signal manually ?. I am using NI Robotics Starterkit 1.0 and my software version is 2013.

I have another thing to ask. In Robotics Project the Project is in FPGA Interface Mode but there is no VI under FPGA. Only one VI under the sbRIO. So, how actually they are accessing the I/O ? I have tried to drag and drop the I/Os but it shows BROKEN VI with an error showing "not supported in this Target" .

Best,

Kazi Mashfique Hossain 

[RyanPoPo]

Hey Mashfique,

Sorry for the delayed response. I believe that with the Robotics Starter Kit 1.0 you aren't actually suppose to worry about which of the FPGA I/O correspond to which sensor because the Robotics VIs abstract that for you by design. Here's a link that you might find interesting that describes how to communicate with the FPGA to steer a robot using either the Servo's angular position or velocity:

http://zone.ni.com/reference/en-XX/help/372983D-01/lvrobogsm/robo_skit_programming/#skit_steering

In the above link for example, they mention using the Write Sensor Servo Angle VI to set the angle that you want to rotate the Servo to.

Regards,

Ryan