Well I'm finally done with school for the summer. Amazing how an 8 week 5 credit math class could soak up so much of my time! So I apologize for the delay in progress. I now have a lot more time in the mornings so I think I might be able to get some things done before classes start again in late August. I did manage to get out and do the very first long duration drive over the Solstice weekend in June. That was really exciting because I had the sun's full power and a big open parking lot to drive around in.
So with this test I got to see how much power the solar panels were putting out, how long the battery would last, and also got to test the cooling capabilities of one of the micro fans I had purchased a little while ago.
I had a lot of fun just openly traversing this parking lot.
Not much for obstacles but that's ok. I wasn't there to test the suspension.
As you might have noticed, I replaced the metal detector arm with a small fan.
Since I didn't want to cut a hole for the fan just to find out it didn't cool much, I decided to just use the existing hole and the switchable power normally used for the metal detector for this test. I cycled the fan on and off throughout my drive and each time I cycled it off, the internal temperature would climb to around 100F and with the fan on, it would fall to about 95F. Outside temp was around 75F that day. So the one fan test seems to justify cutting a hole in the side for a fan or two.
This video shows what it looks like from my perspective while operating Inspiration.
You can see the single letter commands put in and then getting the action replied back from the rover letting me know that the command was received and executed.
In this picture you can see I came across a small number 5 in the dirt. Too bad I didn't have the metal detector. It would have been fun to sample something that I didn't put down.
(don't mind the battery voltage, I still don't have that hooked up yet.)
Here I was testing the solar panel output and was greatly saddened to see that in full sunlight, it only had a
20 milliAmp draw on it. I'm assuming the battery was providing all of the power to the systems and so this measured power might have been making it's way to the battery or simply taking 20mA's off of the total load on the battery. At any rate, this was never going to charge the battery like I had intended.
So the plan now for battery charging will be to have another battery on board and a small circuit to charge one battery while the other is being used and then be able to switch between the two. This idea came courtesy of fellow student Shawn Doyle who used such circuits during ComSAT communications in the army. So it's gotta work, right? I know simply charging a battery off of the solar panel works pretty well. Oh another flaw in my design was to have an 8 volt regulator in line with the solar panel to battery so I wouldn't risk exploding the battery with the 12 volts from the panel. Well this definitely limits the power from the solar panels and with the way it's wired up, also limits the power from the battery to the systems. So I think with the new charging circuit, I'll have a relay turn off the solar panels when both batteries are at 8 volts that way I'm not limiting the power through a regulator anymore.
And now onto something that I'm very excited about!
This is the new control panel for Inspiration created by fellow student and LabView wiz, Donald Morgan.
He's been working hard on giving all 27ish commands a functional button. And just yesterday I got to watch him integrate the video feed from the rover and also information sent back, into the sidebar. Really amazing work! This is going to change everything when it comes to demonstrations. I might actually feel comfortable letting people drive it now. (ok, maybe after I add steerable wheels so it doesn't tear itself apart anymore)
Oh, I forgot to mention the results of the long duration drive! Inspiration managed to drive for a total of 45 minutes almost non-stop at top speed before the camera started to get fuzzy. I could have probably turned the camera off and got another 20 minutes out of it but realistically, I won't be able to drive without the camera. Unless it's traveling to a GPS waypoint, then I guess I wouldn't need the camera during that time.
Which reminds me!
I managed to test out the GPS unit the other day. On the balcony, I synced up with 9 satellites and found that my location isn't written in a format that Google maps can use so I need to some how convert it by moving a decimal 2 places to the left and adding a negative to the longitude coordinate. When I did that however, it placed me about 10 miles away. So I guess I have some work to do on that. When I get it figured out, Donald thinks he can get Labview to take the location coordinates and plot a course to the selected waypoint. So technically Labview would be controlling the rover at that point. Which I think is really cool! I'm assuming that should free up the Arduino to keep doing other tasks like monitoring the metal detector, scanning for obstacles with the sonic range finder, and allowing me to move the camera.
Hopefully lots more to come in whats left of my summer break. Stay tuned and have fun!
