Update to MultiWii 2.1

I recently updated the MultiWii code running on my quadrotor and computer to MultiWii version 2.1. It bosts several new features such as more GPS support. Unfortunately I am unable to take advantage of this because my GPS uses serial to communicate with the controller. This causes a problem because my CRIUS SE board only has one serial port meaning that I can run the GPS or Bluetooth module but not both at the same time. Although I am relatively confident in the MultiWii GPS code, I’m not comfortable running any autonomous routines without being able to test it first. Testing would require watching the configuration GUI to observe the motor outputs while moving the quad around by hand (with the props off for safety reasons), but while the GPS is attached I will not be able to use the Bluetooth module, thus cutting off my telemetry data.

As for flight performance I didn’t notice much difference. The quadrotor appears to be slightly more stable, although this could just be my imagination. The main improvement is in the configuration GUI. Here a screenshot:

Also, I discovered that there is an Android application that allows for tuning via Bluetooth. Here are some screenshots:

Second scorpion MRI

On Friday (August 3) I was contacted by Rohini Vidya Shankar (a PhD student who works at the MR at Saint Josephs hospital). She asked if I could bring in another scorpion to the lab to image. I could, and I brought the scorpion in as requested. It went the same as previously (see MR imaging) except this time we did not have anyone who knew how to run the anesthetics so I had to kill the scorpion while it was awake. We also used a slightly different technique when putting the scorpion in the 50mL vial. Originally we simply inserted the scorpion, filled the vial with the perfluorinated fluid, and screwed on the cap, but this always resulted in a small bubble (which can create an artifact by distorting the magnetic signal). This time however, instead of using only the vial cap, we stretched several layers of parafilm (like super plastic wrap) over the top of the vial and pushed the bubbles out. We then screwed the cap over the parafilm, eliminating the bubble and creating a tightly sealed container.

Here are some pictures of the lab: