Hey Guys,
It’s been a while since I posted an update on SAGAR, but here’s the latest.
I wanted her to go faster. My original motors would only do about 1.2 m/s tops. Well, with a little help from a friend, I found new motors that would bring up the top speed to well over 3 m/s. However, they require more current to reach that speed, more then my original controller could handle. So it had to be replaced.
I wanted to be able to get information back from Google Earth. It’s already easy to plot information on Google Earth, but getting information back, like the GPS coordinates under the mouse pointer, was another story. Well, I slaved myself to my desk for a few days and figured it out. I created a sample VI program that displays the GPS coordinates of the Mouse over the globe, and captures the coordinates on a left mouse click. It then feeds them back into Google Earth as a point.
The first fully working version (v1.0) is now available. I split this into a new blog post, as many things have changed.
The big change is you can now define what pins of the Arduino are used, no longer are you tied to pins 10-13.
Also, vibration (Rumble) and analog button pressure readings (how hard is a button being pressed) are now working.
My SAGAR project has gotten to a point where I would like to document the system design through a series of detailed posts.
First I’ll show the new interface, and talk about how it communicates with SAGAR.
Here is a video of the new interface, with an inset of SAGAR as it runs the mission.
NMCI friendly:
In a joint effort between my girlfriend and I, SAGAR now has a super fancy LabView based graphical user interface. The video below is a screen capture of the interface as SAGAR runs a mission taking it around a parking lot. All communications are in the form of NMEA sentences. The DIYdrones ground station gave us a few ideas of what we wanted to do.
Ok, so I’m a little overexcited. I just got back from watching SAGAR complete it’s first autonomous mission. I just finished coding the navigation functions and couldn’t wait till the next day to test. Attached is an image of the mission it ran.
I used a Ardupilot program to generate the mission file with waypoints, convert it to a hex file using gcc, and I manually flash that into the Axon’s EEPROM memory. When SAGAR comes online, I give it a command to scan the mission file in memory, then I command it to run the mission.
I have been asked by a few people how SAGAR is going, so I guess I need to do some updates more often. Anyway, SAGAR was shelved for a while. The last tests of the closed loop heading controller showed I had something messing with the compass readings. Further tests concluded that my batteries were biasing my compass.
While waiting for parts to come in for SAGAR, I decided I’d kill three birds with one stone. I wanted to adapt my Irobot command code to be compatible with Webbot’s Lib, I wanted to test Webbot’s new Project designer, and I wanted to try out a Force Field Obstacle Avoidance Algorithm. This is what I came up with.
Not all my projects are robotic in nature. This one, a simple water change system for our 40 gallon saltwater tank, is one of those non-robotic projects. For those who are unfamiliar with fish tanks, about once a week you have to change out roughly 10% of the water. The way we have been doing water changes involved two trips to the toilet with a mob bucket, and a lot of mixing of water in the shower. I decided to build a better way.
Here is a video of the LED Lab Coat with the better PWM code. If you are interested in how I programed 8 channels of software PWM, here is the source available for download.
