After several hours perfecting our system in the lab, we decided to get ourselves some fresh air…though not without one final check over the setup by our resident comm expert.
Once Ryan was satisfied with the equipment, we finally got off our butts and headed outside.
Of course, we get two steps out the door and have to spend the next 15 minutes adjusting everything so that it actually works the way we want it to. But is isn’t terribly long until we are ready to hit the road and start our test.
Thus began our journey around north campus. I have provided the maps below with the relevant GPS data (red line) as well as our actual path (blue dots). To differentiate between the multiple paths shown (mainly on GPS) I also included directional arrows to indicate which path we are looking at…
From the look of it, we were off to a great start in tracking our progress. Actually this was mostly expected due to the difficulty of obtaining a signal from inside the SRB. Most people have a hard enough time navigating that building so we really can blame the poor GPS.
Once we worked out the bugs, we were able to set out on our test run. Getting out of the parking lot, we had a few line-of-sight problems, but, all-in-all the GPS did a pretty decent job tracking the route.
On the way down Hayward, there was considerable deviation from the path, possibly due to a lack of sight from our chaser car (Read: Ashwin drives too slow :P)
For straight road, we have great results even when there was considerable distance between the two cars.
We did find that the GPS has trouble with turns and circles (not unexpected since we transmit every 7 seconds). The X was where we had to stop and Evan took the opportunity to harass Dave.
And pick on the poor chaser car behind us.
But it wasn’t long until we were back on our way.
As with the trip down Huron, the GPS performed adequately on straight roads with some trouble during turns. It wasn’t until we returned to campus that we had any trouble with the equipment.
After the chase car (green dots) lost track of us between the two green X’s (thus severing any line-of-sight) the radio could not receive any data for over half the track. What was surprising was that we maintained communication before reconnecting with the chaser car (loss indicated between the blue X’s).
We took some time out to test how far we can push the chaser car before they quit on us. We aren’t quite certain of the results - it’s very difficult to see the looks on Ryan and Ashwin’s faces from here.
We can really only compare it to the overwhelming look of relief they gave us when we finally exited the parking lot.
Following our parking lot test, we decided to try the North campus route one more time where we met with considerably more success.
With this, we were done - having considered ourselves pretty successful. Now we’re tired and are going to sleep. Please enjoy this encore picture of our payload:
The last few weeks have been crazy busy and, as such, we (ok ok, I) fell behind on the most honorable duty of maintaining the very voice of this project.
With that said, this post shall serve as the bridge to bring the enthusiastic viewer up-to-date on the project and ready for the plethora of information to come this weekend (and pictures, lots and lots of those to take up space and make it seem like we are doing something).
First and foremost, we will be flying next week. Or, rather, we intend on flying next week. This is, of course, pending any natural disasters and the possibility of setting anything on fire (you never know).
How did we get to this point you might ask? Well, our boards came in and are completely assembled, our TNC-X is FINALLY cooperating, Dave has a fully functioning flight code, our structure is shaping up (literally), we have built gorgeous antennas, and we will be pulling some fancy hours this weekend to finish the following tests:
1) GPS logging test (collect data for at least 2hrs)
2) Camera logging test (camera data for at least 2hrs)
3) Car Chase test (take two cars, follow each other, communicate, track on a map, etc)
4) Temperature test (freeze the entire package and collect sensor data for at least 2 hrs)
This weekend, expect several posts with our test data, relevant design pictures, and whatever else we wish to throw in there. Til then, please enjoy this little clip of Dave’s flight code results:
They're so still. The trees? What did you expect? They used to dance.
Holy Updates Batman!
Anywho, a lot has happened in the past few weeks and we have been up to unbloggable heads in work to do.
Before I start, I have a bit of good news: After weeks of patiently waiting, we have finally received our netbooks! So now, without further adieu, I would like to introduce the two newest members of our team: Comm-et and Code-y.
Comm-et (aka Acerone)
Interests: HAM Radio, Amateur Bands, Rubber Ducky Antennas
Bio: Since childhood, Comm-et has dreamed of being a HAM radio operator and had dedicated the golden years of his life dutifully studying for the test. Unfortunately, his hopes were crushed upon that fateful day when he was so kindly informed that netbooks cannot obtain Amateur radio licenses as they are not, in fact, people. Since then, Comm-et has spent the better part of the recent past performing odd jobs here and there until he signed on to our communications team. While it isn’t as satisfying as the life of an operator, Comm-et still takes solace in his duties for the team.
Bio: Code-y is a netbook of few words. Always a wiz with various gadgets, he prefers a simple evening disassembling components to the typical netbook night life. What we do know is he is always enthusiastic to lend his expertise to those in need and looks forward to the project.
Recent progress has left us hopeful of maintaining schedule without any significant periods of panic. As of this week, we have obtained all of our core components and now find ourselves in a position to start putting the pieces together. Goodness gracious we might actually start looking like we know what we’re doing!
In terms of advancement, the most notable element is the finalization of our board designs. Thanks to our ‘closet EECS’ extraordinaire, we now have our boards on order to arrive within the next week. For your amusement (not to mention our overwhelming pride) I have been so kind as to include a picture of our designs below.
Additionally, the team is hard at work testing and altering various components for the project as we piece our way to the end. Today ended with a rough note on one of the cameras and we are still waiting on more news to know if it will survive the encounter.
Two days ago, I didn't believe in the existence of talking animals... of dwarves or... or centaurs.
These past weeks have provided the fine citizens of Narnia with a lot of work before them. Following our former success in both foraging for and ordering components, we have since been conducting functionality tests to characterize the merits of each component. A formal outline of our progress is below…
Perhaps the most excitement has come from the two GPS units (the Garmin 35 and 18). A visit from the kindhearted GPS fairy (thank you Brad!) has granted us with the knowledge and initial testing to prove that our Garmin 18 works (very well I might add) and is ready join our balloon adventure. More formal testing and integration will follow.
Figure 1: GPS Fairy (Note: Not drawn to scale)
Unfortunately, our luck was not with us for the second GPS, the Garmin 35. Following a rush soldering procedure to reattach some loose wires, the GPS was set on power supply life support but showed no response to treatment and the unit was pronounced ‘junk’. A later autopsy revealed that the unit short was internal and probably due to exposure of a 9V load over a 3-6V allowance. TOD was indeterminate. Narnia greatly mourned this loss but, like all good projects, we had to move on…
In what was almost ‘too good to be true’, we came into possession of not one, but two Alinco radios. All was going well until it came time to test them and we couldn’t get any sort of response from one of the units. Our hearts sank to the floor but one brave member of our team refused to give up on the little guy. With the right amount of nurturing, the radio was able to pull through and deliver a strong signal to lift the hearts of those around it.
In addition to those parts found around the lab, several items arrived from our outgoing orders - namely the MCU, humidity sensors, temp sensors, and a plethora of connectors and other tidbits to our design.
We are still waiting on our secondary TNC-X, both cameras, the batteries, the antenna, and the APRS.
Although, some good news on this - even though we don’t have everything in hand, we are still able to determine our (semi-final) layout design (See below). This is only the internal structure (note the absence of thermal protection and cameras) but it gives a good idea of placement and sizing restrictions.
And what about you? You must be some kind of beardless dwarf? I'm not a dwarf! I'm a girl. And actually, I'm tallest in my class...
Following our most recent set of trade studies and a rather successful trip to the lab where no one received any serious injuries (for the record losing fingers doesn’t count), we now find ourselves with considerable knowledge (and when the scavenging is good, possession) of the majority of our main components…
Since this subsystem is proving to be the heftiest in terms of cost, it has earned itself top billing on our discussion (perhaps we should remove some of its advertising budget).
For our discussion, we will start from the ground up *cough* bad ground station joke *cough*…
Figure 1: Our Ground Station Lineup
To conserve resources, we have decided to equip only one car with a radio and GPS receiver. This will allow us to utilize the two Alinco radios from the lab as well as one of the TNC-X units, thus eliminating their costs from our budget.
Some of the more noteworthy payload components here are the Alinco DJ-S11T Radio, the MicroTrak 8000 FA APRS Transmitter, the Garmin 18 GPS, and the Byonic V3 Antenna.
Like most of our components, the driving force here was cost. We wanted to find the sensor that could do what we needed at the lowest price. This unfortunately resulted in the loss of many bells and whistles but allowed us the margin to afford a camcorder for our secondary visual source (thus gaining +10 to awesomeness for our project). This isn’t to say we don’t like our stationary camera (Argus Bean A5650 seen below in all of its cuteness), we just like variety.
Figure 2: The Argus Bean
Some of the additional noteworthy items include the Sony MHS-PM1 Webbie Camcorder, Humidity and Temperature Sensors from Digikey, and a 3-Axis Accelerometer from Sparkfun
C&DH and EPS
At the heart of our payload lies the central control system and the source of all power. To manage this most efficiently, we have chosen the Arduino NANO as our microcontroller (see Figure 3 below). From our research, this unit should be able to support all of our systems (with the Parallax Memory Stick Datalogger).
Figure 3: Arduino NANO MCU
Additionally, our system will fail without power. To rectify this, we will also use 6 Energizer L91 batteries (creating a total of 9V).
She thinks she's found a magical land... In the upstairs wardrobe
Narnia is off to a strong start following our PDR last Thursday. As such, we decided to celebrate with a lengthy blog chocked full of nutritious and delicious balloon bits…
Post PDR Questions, Comments, and Concerns…
We received several helpful comments and suggestions we need to take into account:
GPS: Our final decision on this was the Garmin 18. We went with the 18 model due to its lower power consumption (roughly half). We can get this from Ritz camera. Additionally, the lab has a Garmin 35 which we might adopt for a car tracker.
Some concerns we still need to take into consideration:
How many units are you planning on having?We aren’t sure yet but we think we will be using 3
Can you feed one GPS into 3 different serial connection? Also, are you planning on storing the GPS data in the data logger (why is it being fed through the MCU)? We plan to store the GPS data in the MCU (‘file o’doom) but we are still unsure as to how this will be done. More investigation needed.
Cameras:Our original choice for a digital camera was a little too good for our requirements - ok so we don’t need 12MP of awesomeness despite how good the desktop pictures would have been. To accommodate this concern (and drive the cost down) we turned to a 5.1MP camera (most likely the Argus Bean A5650). The requirements for this model are reasonable and the consumer reviews are encouraging.
Additional camera concerns are as follows:
What are the cameras rated for as far as temperature? From what we found, most cameras have a typical operating temperature between 40 and 0 degrees (C). A lot of this is driven by the batteries so we are going decouple the batteries and run power to the cameras so that they are kept warm near the center of the package.
How are we going to protect the cameras from cold conditions? Aside from protecting the batteries separately, each camera will be submerged into the Styrofoam insulation - possibly fitted into their own thermal ‘blanket’ and then inserted into their slot. The structures/thermal team is investigating this point and will provide updates accordingly.
How will camera data be stored?Both cameras have internal storage that is more than adequate for our application (SD cards). We won’t be feeding any of this data through the MCU.
In addition to finalizing trade studies, we have a lot of work on our hands. We still need to decide on a power system (thus requiring a finalized power budget and braving the information overload on the some of the more prominent battery websites).
On the topic of budgets… We are putting the finishing touches on cost (we currently have funds leftover!) and creating detailed mass and volume budgets to avoid any circumstance resembling When You Give a Mouse a Cookie.
Struct/Therm needs a more concrete design (not to be mistaken for a concrete structure, of course). This will entail layout estimates, thermal concerns, and materials.
Comms. is currently researching alternative architectures aside from our original Alinco design in favor of just APRS. There is also a strong concern in determining the method of activating our FTU
C&DH has more than enough to do with research, boards, and programming.