April 2010 Archives
2010-04-26
Angular rate driver work finished
Last week I finished the contract work for the angular rate drivers I mentioned in my last post.
During the final meeting we also verified that the output of the sensors are what we expect them to be. While coding them I was able to check that I'm using the right registers, values are changing when I turn the device, but I had no test equipment to see if the measurement is really correct.
At the DLR we could use an angular rate table for this. The device itself was mounted on the rotating table with power and data connection on sliding contacts. Some pictures of the setup can be found here.
From the measurement point the MLX90609 and the SAR100 variant we used are quite different. The MLX is capable of 300 degree per second while the SAR100 was able to measure 1500. In our test we even had good results with 1800. During this testing we found a bit different offsets as described in the data sheets but still pretty close to what we expected.
I'm really looking forward to the launch of the rocket to hear about the results the sensors produced and how it compares to the big money equipment that it used for the flight control of the rocket. Once the rocket is back and the data is analyzed I also should be able to get a board back and do my part on getting the drivers into mainline. For now I have posted them as demo to the openmoko kernel list.