Update:

I made some changes in the design today because I came up with the idea for future launches. I decided going forward I would include a hitchhiker. A hitchhiker is someone who wants to perform an upper atmospheric experiment without the hassle of the whole balloon thing. I have not worked out all the details yet but basically I will provide 5VDC, one parallel process, and 4 pins to perform whatever experiment. The electronics must fit on a Hitchhiker PCB (1.5"x2.75") that will attach directly to the MPFC. The experiment must weight less then 1 lb (exact weight TBD) and can be inside and/or outside the capsule. If someone does not want to use SPIN then they can design there own computer controlled experiment and just use the 5VDC provided for power. If you think this is something you would be interested in doing drop me an email. You would be responsible for engineering your experiment and the cost associated with it. If you are selected and your experiment meets my power, size, and weight requirements I will give it a free ride into near space and return the experiment and any data back to you. I will provide further details over the next several days.

8/12/08
I did a bunch of house cleaning today with my code by moving some procedures around to help it make more sense and thoroughly documenting each procedure and lines of codes that I thought needed some sort of comment. It is probably overly documented but more is better in this case. I also added additional functionality to my spreadsheet. the new features include the Laws of Cosines to find distance between points and horizontal speed. Now I know the Haversine formula is better but in this case the horizontal distances are small and the accuracy will be within meters. Close enough for my work. If you prefer to use th Haversine formula and want to update the spreadsheet I will be happy to post it on my website.

I decided not to wait for the SEI team to get back to me on my offer of installing a second camera and decided to setup the MPFC board to accept a small daughter card that will provide a signal line and power. This way I can install a second camera, beacon system, or ultimately my own APRS system without having to recreate the board.

I need to update my schematic with the new adapter idea then I can update the PCB and double check it. I am hoping to get that done by this weekend. This past week I completed the first and second phase of system testing, updated my ground tracking stations, added additional functionality to my spreadhsheet, and added the lastest Spin code which will only change if I add a second camera.

SPIN Code - HAPB-4.SPIN (SPIN code can be opened with a text editor)
Excel Spreadsheet used to format KML file

MultiProcessor Flight Computer (MPFC)

I have started working on HAPB-4. It will be using Parallax's SPIN Stamp which contains 8 micro processors known as COGs. Each COG can operate independently or in a cooperative environment, leaving me with an unlimited number of ways to use the micro-processor. I also like the fact that it is in the Stamp format. The Spin Stamp module is not intended to be a direct drop-in replacement for any BASIC Stamp module and there are some important points to consider before purchasing the Spin Stamp but it can be a less intimidating method of moving to the Propeller.

I kept the basic functionality of HAPB-3 with a few exceptions. I have pulled the temperature probes since my APRS unit already has that function. I am also replacing the 32K EEPROM with Parallax's Memory Stick Datalogger. Finally, I removed the CRDR reset, SFC Satellite Acquired indicator, and the SFC. It sounds like a lot of chances but its not. The functionality will be incorporated into the SPIN Stamp so I do not need the second processor and associated supporting hardware.

The LCD, GPS, and USB code has been finalized. Up until now the propeller was executing code in serial fashion much like the STAMP until I gave the procedures there own memory stack. You can see where the power of the propeller comes into play once you start using multiple COGs running parallel processes. You can run out of COGs very easily and now I understand why people would like to see additional COGs built into the chip. I am using all 8 COGs for this flight. If I need additional parallel processes then I will switch the External Signalling processes back to COG 0 but for now I will leave it as is because I can be COG-HAPPY until I really need them.

COG 0 - Main program space
COG 1 - LCD operations
COG 2 - LCD Serial operation
COG 3 - GPS operations
COG 4 - GPS Serial operations
COG 5 - USB Drive
COG 6 - USB Serial operations
COG 7 - External Signalling

This flight I will be recording GGA data every 4 seconds which means I will be provided with 3600 data points over a 4 hour period for a file size of ~295.2KB.  That is a big jump from my previous flight of only 200 data points.  I should be able to get a better idea of maximum altitude this flight.

SPIN Code - HAPB-4.SPIN
JPEG/BMP versions of the schematic and layout.
ExpressPCB versions of the schematic and layout.

Telemetry System

I am using the same telemetry system from HAPB-3 with no modifications. I have plans of replacing this unit with own using the propeller but that is for a later flight and for a joint project I am working on with my friend Paul Hubner and his PNAV project. You should check out his project. For now, I will continue to use the Opentracker until I get a better handle on the Spin language.

System Testing (In-Progress)

The first round testing was done on my protoboard and the results looked really good. I ran the system while going back and forward to work with the GPS recording data every 4 seconds. For now I am using a light toggling on and off to emulate the camera operations.

I completed the second set of system tests today. All systems functioned properly during my journey all over Dallas. I like it when things come together. I have uploaded the data in KML format for those that have Google Earth if you want to take a look. I worked on an excel spreadsheet that will automatically format my raw data simply by pasting it in column A and then I copy the KML column in the spreadsheet in a KML file under the cooridinates section. The process takes 1 minute.

KML File - HAPB-4-Test (Right click and "Save Target As", then double click to open in Google Earth)
Excel Spreadsheet used to format KML file

Launch Day (Pending)
Recovery (Pending)
Damage Assessment (Pending)

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