And that’s a wrap. Well, almost. I need to bump up the amplification on the headlights and decal the model, but other than that, it is finished! The entire point of the exercise was a proof of concept on an accurate modern emergency vehicle lightbar, and boy oh boy did I learn a lot along the way. I’ll list those things after the video.
As the prototype of what is sure to be many incarnations to come, I dub this ’07 Ford Shelby GT500 my ‘Demonstrator‘! Please ignore the 8xAA battery pack on the side. Normally, this car can be powered by a 9V that fits nicely into the engine compartment, but I was plumb out of 9V batteries. Yes, there’s some in the house smoke detectors, but Murphey’s Laws have taught me a thing or two, so I left those 9Vs where they were 🙂 Anyways, using a 8xAA power supply tested the circuitry against a 12V source, so it’s all good! Enjoy:
Demonstrator: 1:24 Model Whelen Liberty Police Lightbar from claymore1977 on Vimeo.
The lightbar project work continues! All the proper ohm value SMD resistors *finally* arrived in the mail, and a few short evening work sessions later, the resistors are in place, dud LED light modules replaced and leads carefully soldered in… we have an operational Lightbar!
Now, the front 3 Red and 3 Blue are electrically different than the rear 3 Red and 3 Blue, so add in the working center takedown and 2 alley lights, there are 15 independent LED modules on this bar. However, the software that was on the MSP430 I hooked them up to only was written for the front 3 Red and 3 Blue only, so the bar is not flashing at its full potential…. yet!
Here’s a short video that’s a bit out of focus. I didn’t catch the focus issue when I uploaded it because it was well past midnight 🙂 Once I update the software I’ll film a higher quality version.
1:24 Model Whelen Liberty Police Lightbar from claymore1977 on Vimeo.
Work on the 1:24 Whelen Liberty Lightbar continues. My order of 0805 SMD resistors I ordered from Garrett Electronics Corporation via Amazon.com arrived in the mail yesterday, so I was able to mount them onto the lightbar. Goodness me those things are small! I’ve got to find some better techniques at soldering if I want to ever tackle a project using 0603 LEDs/resistors….
My apologies for the dark pictures, but I haven’t figured out a good lighting solution yet and the iPhone camera really works best with a lot of light.
Here is a shot of them mounted on the underside of the light bar. The lightbar itself is only 50mm wide, 10mm deep and 4mm tall. Talk about a pain to solder in place!
Here is a project idea for some of you. If you are anything like me and you are experimenting with an Arduino or TI Launchpad for the purposes of your model railroad, then you likely find yourself adding and removing LEDs and associated resistors to/from breadboards over and over again. So it dawned on me: Why not solder some LEDs and appropriate resistors for a 3.3V source onto a spare PCB project board and slap some headers on there? Well, since I was waiting for some parts for other MSP430 projects, I did just that!
Well, the last lightbar was a technical success that met with an unfortunate fate when it shifted inside it’s resin cast. Really, it is a shame because I was very happy with it. But with every failure comes knowledge and lessons learned, so I am moving on without too much angst.
I have targeted a prototype model light bar (Liberty™ SR WeCan® Series Super-LED®) and have also figured out a better manufacturing process. Still not fool proof and does not yield a perfect ‘machine made’ look, but it is infinitely better than last time. Solder traces are much smaller and more accurate. There are 60 LEDs (1206 SMD) this time around grouped into 15 groups and include a Takedown light and left/right Alley lights. At 1:24, the lightbar measures about 44mm wide, 10mm deep and 3mm tall. Keeping the ‘tall’ measurement down in order to mimic the very low profile of the prototype is harder than it appears!
Soldering 1206 SMD LEDs by hand is a bit of a pain, but with practice, I’m getting better. I am still having trouble fathoming soldering 0805’s or 0603’s by hand… yikes.
I’m waiting on some SMD resistors to solder onto the underside of the lightbar, then I’ll have the green light to finish wire it up and test the software.
I’m having a blast!