sbrio

[suzane.b]

i m doing my final year project with sbrio, in my project m using a simple path planning algorithm in which the sbrio has to reach the target avoiding the obstacle, while the sbrio travel the co-ordinates needs to be check n updating the co-ordinates is required so i will be using gps, i will b testing the project in a room only, can you please help me in finding out which gps module wil b feasible with sbrio 9631

[Lewis_G]

Hey,

I'm using an sbRIO for my third year project too.  Im building a fixed wing plane that will stable itself hopefully.  I'm using an xsens MTi-G that plugs straight into the sbRIO via RS232.  If you had budget for the MTi-G I could give you some code so you could get GPS data within minutes.  I would imagine the MTi-G is overkill for you though.

I would advise looking for a serial RS232 gps module for its plug and play nature.  The other options would be to communicate with a GPS module via the FPGA using I2C or SPI which would be harder.

This may help if you chose I2C.

Heads up, GPS does not work very well indoors and even if you do get a good signal, GPS is accurate to meters.  You would probably be better off using a over head camera if you want to track your robot in doors.

Hope this helps.

[Adesolmi]

Hey,

I am very late but I'm working in project with an sbRIO and a MTi-G so I am very interested in your code!

Thanks for your help!

PS : It is for my third year project as well!

[Lewis_G]

I have finished a driver for the xsens MTi-G which you can download here

[fredlepiv]

Thanks a lot!

I'll try asap.

[syafiq]

Hi Lewis,

I have tried out your MTI-g driver code and it works fine for my MTx IMU. I managed to get the Euler angles reading from the IMU using 'Read Single Data' function in a single While loop execution. Then, I used this piece of code together with other Timed while loops that implement the control calculation , FPGA execution (servo PWM read and control) and ANN (no training) model estimation. All of the Timed while loops run at much lower frequency (50Hz). The data transfer from the IMU loop was done through the use of RT variable (array of double).

When I start to run and deploy the whole program into my sbRIO NI9605, I only get the the proper Euler angles reading momentarily before finally arriving at the following VISA error message: (−1073807252) An overrun error occurred during transfer. A character was not read from the hardware before the next character arrived. Do you know how to resolve the problem?

Thanks,

Syafiq

[Lewis_G]

I think this is because you are not reading bytes from the serial port on the sbRIO quick enough; The MT spitting out data faster than you are reading it.

I would say either increase the rate you read from the serial port (loop rate) or set the output frequency of the MT to lower.  When I use the MT, I have a loop dedicated to reading sensor data and then a local variable for my control loop to read the latest angles whenever it needs too.

Search google for "visa 1073807252" and you will find lots of people having the same problem.

[syafiq]

Hi Lewis,

I have tried both of your suggestions but still receiving the same overrun error.