Airframe Test Computer for the LV2c Recovery System Test

Preliminary information on the "quick hack" LPC2148-based timer system used to test the LV2c recovery system in a, umm, ahh, a live aerial test of the system.

The system is based on:

An Olimex LPC-2148H board (here are the schematics and the dimensions.
A Sparkfun VTI SCP1000 breakout board (here is the schematics).
Two 9V batteries.
Two logic level MOSFET switches.
A bright red LED.
A "static line" which is a shorted coaxial connector to act as the trigger the device.

The initial specifications are:

Here's how we envision using it:

Pre-Deployment

Choose fire1_timeout and fire2_timeout values and program them in to the LPC2148.
Test the system (see "Deployment" below) but INSTEAD OF THE IGNITERS use two low wattage 12V incandescent bulbs.

Deployment

Put on the two "REMOVE BEFORE FLIGHT" shorting blocks.
Attch each of the two 9V batteries leads to the terminal block.
- The green (?) power LED should come on.
Attach the Separatation Ring System (SRS) igniter to the Igniter 1 terminal block.
Attach the Line Cutter System (LCS) igniter to the Igniter 2 terminal block.
Strap the Test Computer onto the airframe (good luck!).
Go 2,000ft up.
Attach the shorting coaxial connector securely to something that stays at 2,000ft.
Carefully plug in the shorting coaxial connector into the pigtail.
Verify that the red LED is solid on.
Carefully remove BOTH of the "REMOVE BEFORE FLIGHT" shorting blocks and store them in a safe place.
Get ready to drop the recovery system.
Drop the recovery system such that the shorting coaxial connector gets pulled out as the system drops.
Go 2,00ft down.

Post-Deployment

DO NOT UNPLUG ANYTHING.
Hook up a serial cable to the serial connector.
Tell the LPC2148 to print all of the pressure sensor readings.
Capture and verify you got the data.
Unplug everything