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Archive for February, 2014

26
Feb

Ford SXT Box Lighting

My brother has a fabulous looking black Ford F-150 SXT. He put a tonneau cover (black) on the box to keep things dry and the side effect was that, at night, it’s next to impossible to see anything inside.

Which makes him unhappy:

IMG 4524

So you either get used to packing a flashlight around in your pocket (or are you just happy to see me?), or he calls his older LED fanatic brother and asks, “Whatcha got to fix this?”

I started sleuthing fleaBay (where else) and found scads of LED strip lights. However, one of the requirements was that the LED’s had to be battery operated. There’s a few companies that sell strip lighting strictly for truck boxes but it’s silly expensive in my opinion. I do have to admit they did steer me in the right direction.

What I saw was the great majority of the installs used three double A battery packs. So about 5.25V with fresh batteries, at about 4.5VDC the LED’s probably won’t work well. Typical draw is 16ma per LED. Thus if you put a lot of LED’s on a 3 cell battery pack, you get less battery life and perhaps not a lot more light either. Fine line.

Oddly enough, 5VDC LED strip lights are rare. I found one or two sellers on eBay that offered them. The seller I ordered them from advertised two lengths both with a USB cable for supplying power to them. One strip is 1.65ft, the other 6.6ft. The USB cable is almost 5ft itself. Which turned out handy later on.

LED USB

I chose the 6.6ft strip because it’s better to have too many than not enough. About $18 USD.

When they finally arrived in the mail, they were waterproof and unlike other waterproof ones I’d ordered, they didn’t stink because of the waterproof coating. Well, not too badly anyway. It went away in a few hours.

WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING!

I almost plugged in the string to the USB port on my computer to see if they worked. I say almost because I had a moment of devine intervention telling me NOT to do that!

Instead I plugged them into my home built 5V bench supply that I have a panel of USB connectors on. It can supply 5A at 5VDC through the USB connectors and I have an ammeter on the output to see what the current draw is. A 6.6ft string of these 5050 LED’s pulls 1.65A!

A stock USB port couldn’t supply that kind of current. Max for those, and that’s iffy, is 500ma. Closer to 350-400ma in my experience.

When I looked up the 1.6ft strips the same seller had, I found it used 350ma. So it would be okay to run from USB, but not the 6.6ft!

For a battery box, I decided that I’d use a 4xAA size and modify it. I made it a 3 cell holder and the fourth cell area would be for the switch:

IMG 4523

The switch is a SPDT, 10A and I use one of my helicopter JST battery power connectors so I can disconnect the batteries from the LED’s to change the batteries. The important part is the switch fits right inside the battery pack itself.

We’d decided that we were going to mount the battery pack and LED’s on the plastic box liner itself. Close to the back so it’s easy to reach. I used automotive double sided tape to stick the battery box and the LED’s. True the LED’s come with tape, but the red automotive stuff I use sticks better I believe.

IMG 4526

Where the battery and LED’s are mounted it under the tonneau cover so they stay dry. And even if corrosion sets in, the battery box is under a couple of bucks to replace. We put strips on BOTH sides at the back so it wouldn’t matter which side you were on, there is a set of lights there. Turn on both sets if he needs it.

In operation:

IMG 4527

If you’re counting, there are 12 LED’s and at 16ma per LED, that’s 192ma. The batteries aren’t going to go dead in 10 minutes.

So what’s the illumination like? Well that’s the surprising part. We tested it in the garage at night and it didn’t really seem that bright. Even when I turned off the ceiling lights in the garage it was sort of meagre at best. BUT when we moved the truck outside where there is little to no light, our eyes adjusted to the darkness. When we flipped the LED’s on both sides, HUGE bright inside! Thus, the darker outside, the better!

So what looked like a cave, is now lit up quite nicely:

IMG 4531

The other area that’s dark in the truck is the rear passenger area. The dome light is too far forward to adequately light the rear seats and floor. If you drop something on the floor back there, check for it the next day when the sun comes up. Or find a flashlight.

Since I still had the LED strip with the USB connector attached, and the Ford has a USB plug on the dash, we started looking at using it.

I wish I’d have taken a photo of it, but on the console, there is a rear drink tray that folds down for the rear passengers. Under the tray (it sits right on the floor) there is a recess that’s about 1/2″ high and 9 inches long. I trimmed down the string of LED’s to fit in this recess, ran the cable under the front seats to the dash. The rear LED’s draw 96ma (6 LED’s).

We got a 12V/USB power switch adapter than fits in the cigarette lighter and with a simple flip of a switch, the LED’s light up the whole rear floor area. Works really slick. The drink tray still works the same and doesn’t interfere with anything. Plus even with it down, the LED’s still flood light out on the floor.

All in all, a very illuminating evening with my brother.

18
Feb

ArduWalk

I was taking the garbage out to the road the other night. Course it was one of those cold, rainy, dark nights that occupy much of the winter in our area. The back of the house in the middle has a motion detector outdoor light as does the side middle of the house.

However, those two lights don’t do anything to light up the back corner of the house where the gate is. So it’s a pain to navigate around out there in the dark.

Which of course got me to, well, thinking. I have lots of LED strip lights. Unfortunately, non-waterproof ones as it turns out. I did some rough calculations and I decided I needed two 15 foot strips of water proof LED’s. I didn’t want to have to dig up anything around the sidewalk or put in those silly solar lights on a pole. I’d probably rip those out out the first time I used the weed whacker.

I noticed that where the side walk is darkest there are two bays that over hang the sidewalk. One is for the family room window, the other is for the fireplace. In both cases, neither go all the way down to the sidewalk. My plan, at this point, is to build a subframe under the bay portions and attach the LED strips to that frame. Thus, the LED’s are on order.

Next up, I needed to light them. According to the spec’s of the LED’s, about 12V at 10A. I immediately thought of one of those computer type power supplies. I found a reasonably priced 12V 15A switching power supply on eBay and that’s on order.

Which left, how best to control the lights. I looked at some timers, and then I figured I’d be out there setting the time that I want them to come on and go off. The time to shut off is not a big deal really. But the on time is because in the summer it’s daylight until 10pm. Who needs lights to come on at 5pm. Whereas in December, at 4:30pm it’s already dark. Thus, the timer was out.

I then looked at the dusk to dawn controllers. Kind of pricey little guys aren’t they. My experience with them is that I’d rather not use them.

Then I remember my house address lights. Those come on at sunset, go out at sunrise. And, yes, they are run by, no less than, an Arduino with a GPS and transmitter. Since that master GPS clock transmits the date information around the house, I decided to use its date and time and forego putting in a RTC chip. But I could have used an RTC.

I also thought I’d use one of my Arduino Pro Mini’s so, I coupled it with a relay board, RF transceiver (for the GPS signal from my TimeMate), LCD display, and rotary encoder. I modified a basic sketch from my GarbageMate and I was up and running.

IMG 4509

While I could have had the lights stay on all night (until sunrise), I decided that I’d put in a stop time setting, so that’s what the rotary encoder does. I can set the hours and the minutes to shut off.

Which is the point where I ran into the first snag. For the rotary encoder to be useful, it needs an interrupt routine. I was using the “Encoder.h” and “SoftwareSerial.h” libraries and that wasn’t going to happen. I got redefined vector’s. True, I could have used the transceiver on pins 0 and 1 as the normal serial port, but this is a pain if you do code updates because it overlays the normal serial port from USB.

The solution was found at PJRC. Obviously they’ve had the same problem with SoftwareSerial, so they came up with AltSoftSerial. Safe to say with the rotary encoder library “Rotary.h” it works like a champ.

The relay board is just a standard 5V shield with a 10A relay. If it burns out, it’s cheap enough to replace. The Arduino MINI Pro has no USB port, I use a CP2102 breakout shield to program it.

The control unit, is going to be mounted in the crawl space with a single cable leading outside to the LED’s. A nice small project box would be next on my list.

IMG 4510

Inside the left edge of the box is a DC-DC buck converter. I use scads of these things for Arduino projects because they will take the 7-12DC input and drop it down to the 5V the Arduino needs (at a couple of amps too). Then progressing clockwise around the inside of the box, MINI Pro (328/5V), CC1101 serial transceiver, and relay board. The rotary encoder is sitting outside the box on the right.

I use a terminal block on the outside for the connections in, and out of the box.

IMG 4511

For mounting, I don’t screw in the shields. I use an automotive brand double sided tape (it’s red in colour). I used to use foam tape but it’s not as good. The automotive stuff sets up within a day, and while you can still peel it off, it sticks great. I use multiple layers so the solder connections on the bottom of the boards don’t interfere.

Wired up it now looks like this inside:

IMG 4513

Love those Dupont wire cables. For testing I use my 12VDC bench power supply.

Rather than leave a plain aluminum faceplate, I use Rayven Repo Film through a colour laser printer to create something a little more colourful.

ArduWalk

The left arrow indicates it’s DST time (important to know if you want to calculate sunset and sunrise). The “*” shows that the outdoor lights are ON. I.e. sunset is 5:30pm and the current time is 10:26pm so the LED’s are on for the sidewalk. The sketch checks the time every minute and will shut off the LED’s when the trigger time matches.

I’ve included the sketch with this posting so feel free to use it to create your own ArduWalk. Or whatever you need. That’s what Arduino’s are all about.