Redshift Project Depot

FRC 2016 (Stronghold) => Robot Hardware => Topic started by: Louis L on February 04, 2016, 08:49:33 PM

Title: hardware group, please account for and install Camera and Sonar
Post by: Louis L on February 04, 2016, 08:49:33 PM
Camera: After comparing the video output of the Axis and Microsoft camera, we have decided to stick to the tried and true Axis camera. So hardware folks - please figure out where to mount this camera. Ideally it should be in the line of sight of the shooter (down the middle if possible!).

Sonar: We would also like to have 2 sonars mounted to the front of the chassis, pointing forwards. We still need to figure out how far back they need to be mounted so that we meet their minimum distance requirements - consider this a heads-up.

tkx!
-lou
Title: Re: hardware group, please account for and install Camera and Sonar
Post by: Louis L on February 05, 2016, 10:47:56 AM
We've received a Maxbotix sonar each year so we should have 5 of them. Last night we noticed that they can be rather difficult to identify (at least the 2 we were holding) so we'll have to do some testing if this proves true for the others as well.

Anway, I looked over my records and found that I ordered these:
2012 - ?
2013 - MB1023 HRLV
2014 - MB1023 HRLV
2015 - MB1240 XL
2016 - MB1220 XL

Since we want 2 similar units we should use the MB1023.

The next issue is how to use 2 of them. I looked at the LabVIEW library and it seems the default library uses them in continuous mode - it gets turned on and stays on. I haven't looked at the Java or C++ libraries. Maxbotix has a web page that discusses how to use multiple units together.
http://www.maxbotix.com/articles/031.htm (http://www.maxbotix.com/articles/031.htm)

We can connect these in a continuous loop. This will work but isn't the most friendly in terms of spraying the field with ultrasonic pings. Another option is to use an DOUT pin to selectively activate the pings. If we have spare DIO pins this would be the nice way to do it. We could update the existing sonar libraries or just add declare an additional DIO pin on the side.

Here's the web page for the MB-1023:
http://www.maxbotix.com/Ultrasonic_Sensors/MB1023.htm (http://www.maxbotix.com/Ultrasonic_Sensors/MB1023.htm)
and the datasheet:
http://maxbotix.com/documents/HRLV-MaxSonar-EZ_Datasheet.pdf (http://maxbotix.com/documents/HRLV-MaxSonar-EZ_Datasheet.pdf)
Title: Re: hardware group, please account for and install Camera and Sonar
Post by: Louis L on February 06, 2016, 10:45:27 AM
FYI - the minimum distance for the MB-1023 sonars is 11.8 inches (30cm). So they need to be mounted at least that far from the front of the robot (including the bumpers).