Sorry I missed last Wednesday's meeting, but I wasn't quite ready with the
BOB4 evaluation board. Since then, I've finished the board and also made a
lot of e-mail progress on a DVR and the ARTS2 flight computer.
1. BOB4 text overlay demo board. I finally finished the breadboard that
lets us set up the BOB4 from a PC or from a serial port on the lpc2148
Olimex board. I'll be playing with the PC-based configuration program, but
Decade Engineering has example C code that we can adapt for the free-rtos
LPC control. Wouldn't you know it? Decade Engineering just released XBOB-4
a standalone version of BOB-4 in a box. Oh, well, I understand the BOB-4
hookup issues so much better 'cause I mad it up on the fly.
2. ARTS 2 flight controller. This, as many of you know, is going to
control the recovery system for the LV2-c airframe test flight(s). It can
fire two electric matches independently, based on about 5 different
conditions. All these are programmable ahead of time. The board includes
an accelerometer and an altimeter. Typically, i.e., preprogrammed modes,
the accelerometer is used to detect apogee, usually to deploy the drogue
'chute and the altimeter is used to deploy the main parachute.
The programmable conditions for lighting either electric match are:
MECO - Main engine Cutoff
Altitude going up
Altitude going down
Plus, you can configure a delay after the selected event, e.g., 10
seconds after apogee.
The ARTS 2 records altitude and acceleration at a sample rate of your
choosing. After the flight you can download the data for analysis.
I e-mailed Erik Hall at Ozark to see if we could get the data in real time,
to add to the video text overlay. The short answer is "yes." The long
answer has to wait until he returns from a trip -- maybe next Wednesday.
So far, so good.
3. DVR inside the rocket. Last week we discussed the possibility of adding
a solid state (i.e. SD Flash card) digital video recorder inside the rocket,
in case we suffer any video recording problems on the ground (how could that
The good news is that the private investigator market has spawned several
high quality units. I'll bring information next Wednesday. There is indeed
a very nice unit that appears to satisfy all our wants in size,
quality/capacity, controllability, etc. At $549.00 it isn't cheap, though.
It's something to think about.
Hope ta see all y'all on Wednesday,
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