Texas CanSat Competition (with pics)

[Schmitty]

I can't go into too much detail (we're working constantly right now (competition is tomorrow morning)) but I will tomorrow (probably).
CanSat = Can Satellite
Doesn't go into orbit, but is launched by a rocket.

Here's some pics of us assembling the main circuit board for the CanSat. Yes, we are putting it together in a hotel room. :D

We had to custom make our own battery pack.

I'm not in the 7th pic; I'm the one taking the balcony creeper shot.


More to come!

[weasel_master]

Did you test your board yet? It looks like you're missing a solder point on one side of your double sided board.

[19Charlie_84]

What the heck does a can satellite do? Unlock all the blurry channels?

[Schmitty]

Did you test your board yet? It looks like you're missing a solder point on one side of your double sided board.
We just finished all/100% of the hardware, have populated the board completely (pics are missing a few things) and are frantically trying to get all the software to behave properly. Pretty much nothing on it is working (is a major software problem). Thing is none of us are that great at programming in C, so we're struggling. X-(

[drine]

OK you lost me after TEXAS in your header. :icon_biggrin:
I'm always interested in anything that shoots, launches, or explodes. :catcorn:

[Schmitty]

OK you lost me after TEXAS in your header. :icon_biggrin:
I'm always interested in anything that shoots, launches, or explodes. :catcorn:
Teehee. :D

QUICK UPDATE: As you can see in the above pics, we're using two microcontrollers (greater capability, but also greater head scratching) and we finally got the two AVRs (Advanced Virtual RISC) on the controllers to communicate. This is good news.

We need to do now is:
*Receiving telemetry (can now do since AVRs are talking)
*Barometer - info from radio
*Temperature sensors (info from altimeter)
*GPS (this most likely won't work because we're pretty sure its a hardware problem)


Carry on. :America:

[MicroPilot]

This might shed some light on this thread

http://www.cansatcompetition.com/Main.html

[Schmitty]

^Oh yeah, we've been to that site many times.

Well, the competition is over and we're driving back up the Michigan (takes 24 hours) so I've got the time to type!

We ultimately found the problem. The microcontroller wasn't giving the decoupling capacitors enough time to charge, so whenever we would turn on the CanSat, the microcontrollers would look too soon and see caps at not full power and would go into a 'brown-out' mode. We could've solved this problem by simply telling the CanSat to hold it's horses and wait a little longer before starting to execute it's code. :icon_confused:

Another problem we had were with the barometer and the GPS. Initially, we thought the GPS was a hardware problem (got damaged on the way down), but found out we were having a ground loop problem. After we solved the decoupling capacitor problem (never actually implemented fix, didn't figure it out in time) we're pretty sure the GPS would've worked... but it wouldn't've worked anyways because we didn't even write any code for it. The barometric pressure sensor (the altimeter) was a hardware problem. It was broke, plain and simple. It would give back data which it thought was valid. It would tell us the room temp was 500 degrees temp and at super high temperatures. It would also give one set of data one second and another reading another second.

The battery pack also shorted itself out on launch day. We were supposed to mass the satellite (parachute and all) and one of the guys plugged in just the ground wire to the board. Well, while doing this, it made the entire aluminum structure the ground and the source wire was touching the structure. I was holding it and touched the batteries and noticed they were really hot. I told the guy that plugged it in and he touched them, but he pressed really hard on them and actually burned his finger. We drained the batteries to 0.000 volts before we realized it. :eek:



Attached are some shots of the finished CanSat (minus the custom made (by us!) battery pack). The batteries would've gone in the empty spot on the bottom. Out of all the CanSats there, I think ours is the most robust and professional looking, even more than MIT's or Virginia Tech's. Their structures were plastic and had bunches of wire all over the place. MIT's was actually one of the crappiest looking, not that looks matter. The University of Maryland had a mostly plastic structure and a ridiculously crude circuit board....but they took first place!