04 April 2006
Open Testbed Setup
)Published on April 4th, 2006 @ 09:59:43 pm, using 603 words, 4998 views
Testing the wiring and ignition activation.
Now that all the parts for the Acura-ITX computer have arrived, I set up the complete system in an open testbed environment, and ran full-lengths of wiring to simulate the situation in the car, testing for voltage dropoff, audio signal dropoff, etc. Admittedly, the system will probably face slightly different signal degradation, dropoffs, and transients once in a vehicle environment, but until I've had a chance to fabricate a dashboard chassis and faceplate, I wanted to get the system running and the software installed.
The Opus 120 connected to the vehicle battery.
Using a spare automotive battery, I rigged a set of connectors and ran power to the Opus 120 DC-DC power supply which will run the system, watch for ignition ON and OFF states, and also monitor battery voltage to prevent battery drain. I ran a length of 10AWG wire from the battery's positive terminal, and connected it to the two yellow 12V input wires on the Opus 120. I also connected the two black ground wires from the Opus 120 to the battery's negative terminal. By connecting the red wire from the Opus 120 to the battery's positive terminal, I was then able to simulate the vehicle's ignition being turned on. (Marked by the red asterisk in the wiring diagram above.)
Similarly, the MTSVO-SC motorized in-dash 7" touchscreen is connected to 12V power by way of the Opus 120. I did this by cutting the head from a spare molex connector, and using the yellow and black wires to extend 12' of 16AWG wire, which will be the length of wire to be run from the trunk to the dashboard. Since the screen only uses a max of 1.2A, 16AWG wire is sufficient for the job. Once the screen was wired for power, connecting the red ACC-ON wire from the screen to the battery's positive terminal causes the screen to recognize the "vehicle's" ignition being turned on, and the screen opens. Likewise, removing the screen's red wire from the battery positive terminal causes the screen to automatically close. The image below shows the screen connected and running on a bare windows 2000 installation, showing a fullscreen spectrum and voice-print analyzer mp3 visualization. Since the machine will be designed to run without a keyboard, no ESC key is necessary to exit from full-screen visualizations. Simply touching the screen accomplishes the task.
The MTSVO-SC 7in touchscreen connected to the system.
I'm now using my spare time to tweak the OS so that it runs at a bare minimum. I'm experimenting with the NLite installer software for system loading. It allows the user to strip off all the unnecessary garbage so thoughtfully provided by Microsoft, but which causes a computer to boot and run more slowly than it should. The best part is that it allows these "extras" to be removed prior to OS installation, not afterwards. Once I have the system completely tweaked, I'll create a Ghost image of the system partition and load it onto an isolinux bootloader cd, which will allow me to quickly restore an entire system (in approx 15 minutes) instead of several hours, in the event that the system needs to be reinstalled at some point.
The next step in the project will be to fabricate a mounting bracket and chassis faceplate which will house the stereo headunit and the MTSVO-SC touchscreen in the dashboard.
External: FAQ How to wire an OPUS PSU to your carputer
or, What my speakers are currently pumping...
DJ Spooky - Necropolis (The Dialogic Project)
This post is the creative work of Yours Truly and is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.
Acura, ITX, Opus 120, MTSVO-SC, touchscreen, testbed, ignition, 12v, battery, mobile, computing, interface, shutdown, voltage, car computer
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