DIY Wireless Floodlights for a Lit Skateboard

I had all the worst skateboarding accidents at night.

For those who skate, they know. For those who do not… it’s like this; skateboarding with your eyes closed. You never-ever know what will send you bailing off the board. Perhaps there is a big hole in the ground, a turtle strolling about, or a 2-inch tall ledge in a sidewalk (or no sidewalk, all of the sudden). You are guaranteed to experience fear and pain skating at night.

I finally decided to make what I always wanted ─ Skateboard Floodlights.

It is not enough to just see in front of you, as a skater you need to see all around you. For example, you never know when you may need to make a sharp turn, so it’s best to see where you are about to turn.

My requirements:

- A 360 degree light spread.

- Wireless, and individual, light activation. This way I can turn it all on, while I ride.

- Recharge the lights with a phone charger.

I decided to make skateboard truck risers to house all the electronics and mount the lights. For this version, I went with a rather large 1" tall. I didn't want to limit myself in what I could fit inside these risers.

Despite the simplicity the idea may seem, there are a lot of parts and tool you need!

Shown above is the wireless relay set, the lantern, and the bar of ABS plastic.

Materials Needed

A skateboard (with trucks, bearings, wheels). Your choice!

Two blocks of ABS 1" x 3"

ABS sheet, black, 12" x 12"

A sheet of 1/16” PVC plastic

Lanterns

Extra long skateboard hardware

Remote control relay kit

0.68 ohm power resistor

Boost converter

18650 protected battery

18650 battery holder

Adafruit Micro Lipo w/MicroUSB Jack - USB LiIon/LiPoly charger - v1

Mini-USB male to female micro-USB cable

Push button on/off switch with LED ring

Loctite 1999131 Multi Purpose Repair Putty

75 ohm resistor (for switch LED)

Heat shrink tubing, ¾” as well as various other small sizes

18 gauge wire

Hot glue sticks

Electrical tape, zip strips

Tools Required

Workbench

Drill with bits

Hand files

Scissors

Hacksaw blade with handle

Electrical tape

Soldering iron & solder

Straight edge

Hobby knife

Measuring tools, tape measure, ruler, caliper

Clamps, c-clamps or quick action clamps

Hot glue gun

Scribe

#8-32 tpi tap and a tape handle

#26 drill bit (pilot hole for tap)

Heat gun or mini torch (for the heat shrink tubing)

12mm drill bit

½” drill bit

Prick punch

Hammer

Tin snips

Latex Gloves

Diagonal Cutters

Wire Strippers

Jumper wires with alligator clips at the ends

Small flat tip screwdriver

Take the lantern apart and set it aside, for now....

How we put the skateboard truck hole pattern on the ABS plastic bar and sized it all, is in the video above. Steps outlined below:

- Measure your bolt pattern. Skateboards typically have one of two bolt patterns for the trucks.

- Remove the trucks from the skateboard and lay one upside down as shown on the block of PVC plastic. Scribe the hole positions onto the plastic.

- Remove the truck and use the prick-punch to dimple the center of the scribed circles

- Drill pilot holes in the plastic block. Now drill the holes to size with a 5mm drill bit. Or find one that is about the size of the skateboard hardware.

Cutting out a pocket for the electronics can happen in many different ways.

Here I show a rather crude method.

- Use a hand drill, and drill as many holes around the outline of what you want to cut out.

- Use a keyhole saw, hacksaw blade, or reciprocating saw blade and cut out the webbing between the holes.

- Final step here... use a hand file to smooth down the jagged edges.

This still-frame video shows the second truck being cut on a mill.

The result was a much cleaner cutout. And, for the record, it took far less time. Ask a qualified machinist to give some risers some pockets - if you do not use one yourself.

This project is all about the lights!

Remember those lanterns you took apart? Time to use them.

In the video we show how we attached the LED boards from the lanterns.

Notable parts of the video:

- Aluminum plates were cut and placed behind the LEDs to act as a sort of heatsink.

- Use the LED boards themselves as a template for placing holes in the aluminum plates

- To mount the plates and LED boards to the riser we used two methods; #8-32tpi self threading screws. And we drilled (#26 drill bit for the pilot hole) and tapped one of the risers for #8-32tpi cap-head bolts. Either way works. Since you are threading into plastic, threads could easily get stripped or worn out easily. So, self-threading or mounting screws would probably be the best idea.

- On the front truck, we put in two rows of lights from two lanterns. See above pictures for double light mounting.

On the side of the riser we needed two spots for the on/off push-button and the charger port. Luckily, they both could fit inside a 1/2" hole.

To safely drill these holes with a hand drill, start with a small drill bit and progressively change it out for a larger one. Work your way up to 1/2"

Alternatively, put it in a vice and use a drill press or a mill. Be careful, large drill bits have a tendency to bind.

The pictures show we placed both holes next to each other and near where the truck is mounted.

Solder a pair of 18 gauge wires to the GND and BAT vias on the LiPo PCB. Also, put a drop of solder across the two pads on the board (note the red arrow) to change the charge rate from 100mA to 500mA.

Apply a piece of ¾” heat shrink to the LiPio PCB. Don’t cover up the JST connector.

Use diagonal cutters to remove the aluminum feet and to cut down the terminals on the power resistor.

Solder some 18 gauge wire to the power resistor and then cover the junctions with heat shrink tube.

Load a fully one of the 18650 batteries into a battery holder. Use the jumper wires with the alligator clips at the end to temporarily hook the DC-DC boost converter to the 18650 battery holder. Use a voltmeter and a small flat tip screwdriver to adjust the output of the boost converter to output about 12.2 volts by twisting the tiny screw on the blue potentiometer.

Solder some 18 gauge wires to the inputs and outputs on the boost converter board.

Solder the male JST connector to the battery holder leads. Apply heat shrink tube to all the solder joints. Use a dab of hot glue to stick the wires along the side of the holder.

Solder 18 gauge wire to the switch contacts on the pushbutton. Solder 20 gauge wire to the LED contacts on the pushbutton. Solder the 75 ohm resistor inline with one of the LED leads. It doesn't matter which one. Apply heat shrink tubing to all the solder joints and over the resistor.

Side Lesson to determine the size of the resistor needed for the switch LED. For starters, we know that the LED in the button that we are using for this project is rated at 3 volts. Now, get a potentiometer, ideally something less than 1000 ohms. Wire the battery you intend to use to the LED and the potentiometer as shown in the schematic. If you would prefer, use a power supply and adjust it to output the same voltage as the intended battery. For example, the 18650 outputs about 4.2 volts when fully charged so that's the voltage you would set the power supply at. When that is done, power up the little circuit you made. Now set your VOM for DC voltage and measure the voltage across the LED. Turn the potentiometer until the voltage reads 3 volts. Now shut the power to the circuit off. Set the VOM to measure resistance. And measure the resistance of the potentiometer. Whatever you read on the VOM is the value of the resistor you will need for the LED. Don't worry if you can't a resistor the exact value of the potentiometer. Just use something close. For example, your VOM reads 79 ohms and all you have is a 75 ohm, then use it.

Install the push button in the hole drilled into the truck riser. Stick it in the hole you have already drilled and use a pair of pliers to tighten the included nut down against the inside of the truck riser.

Hot glue the female end of the micro USB extension cable into the second hole in the truck riser. Take your time with this step. You will almost certainly have to apply the glue in stages to build up a large lump of glue where the cable passes into the hole. Be careful not to get any glue into the the USB jack itself.

Hot glue the battery holder, the power resistor, the remote control relay board, and the DC boost converter board into the truck as shown. Make sure that nothing is sticking out past the body of the truck riser. You don’t want anything to get mushed by the deck when the riser is screwed into place.

The above simulation is an approximation of the concept using circuits.io electronics lab. The RED on/off switch is the push-button in the Skateboard Floodlight. The black slider switch is the "wireless" signal. The relay is the on-board relay in the wireless receiver module inside the riser. And the battery park approximates the 4+ volts. You have to turn on the RED switch first to make it all work, just like the real project. The 3 yellow LEDs, in parallel, on the left are the light on the from of the trucks.

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Use the black schematics to wire all the individual components together. Solder all wire connections and then cover with heat shrink tubing. Plug the JST connector from the battery pack into the LiPo charger PCB. Also, plug the Micro USB extension cord into the LiPo PCB.

Note that the LiPo PCB is not glued or fastened to anything inside the space in the truck riser. It is meant to float.

Protip: take a loop of ribbon and put it under the battery as shown in the picture. That way, if you ever have to remove the battery, you don't have to risk damaging it by prying on it. All you have to do is pull on both ends of the ribbon.

Use the Loctite putty to cover up the wires between the LED elements.

This is optional. However, when skating all sorts of debris and obstacles fill your path. Eventually the wires will be damaged, or solder point break off.

The putty adds a layer of protection to sensitive points.

Bolt the completed truck riser to the deck with the extra long truck screws. Make sure that you don't pinch any wires while doing this. If the Micro USB extension cord gives you trouble, loop it up and use some heat shrink tube or tape, or zip strips to hold it into a more compliant shape.

This is the easiest... place a battery (A27) into the remote. Attach it to a belt-loop. This is how you turn on the light.

We could have tied it all together and just used wireless relay board and turned on both sets of lights... however, I felt that perhaps at times, you would only need one. Like the tail-light as a sort of daytime running light for the street. Having the option is key.

We made this project as a way to teach a few concepts:

1. Balancing high-power LEDs with Power-resistors. When LEDs are bright, that is usually an indication that they draw a high current. Typically a resistor is used to limit the current to an LED. But that doesn't mean a large amount is not passed through the resistor, and when it does... the resistor get extremely hot. This could cause a lot of issues - damage to other parts, fire, etc.

That was the case in the Skateboard Floodlights. A 0.68 ohm resistor was needed. Standard resistors were seeing temperatures above 100 degrees C. Hot enough to boil water. We remedied the problem by using a power-resistor. It's designed to handle 50W. In other words, it can handle a lot of heat. With the addition of a heat-sink like shell around the resistor, it would get warm... but not hot to the touch.

2. Using off the shelf wireless relays solved a lot of issues. First, we did not have to build our own wireless system. Saved time and headaches, I am sure. Also... we had a situation where we needed to turn on a system that is out of reach and possible moving without any harm to the user. This gave us exactly what was needed.

3. Discovering the proper resistor to match with an unknown LED. See step 16 to learn all about it.

4. Use of a 18650 battery. A lesser know battery type for common use. This battery packs a huge energy density at over 4V in some cases. If handled correctly, the battery is safe to use. In this project we used one with a protection circuit. This prevents any sort of damage to the cell in use and recharging.

5. Installing a charging circuit into a project is easy to do. Following this guide shows how to connect one to a 18650 battery that is being used to power a system.

6. Use of a ready made DC-DC boost circuit. The 4V from the battery was not enough for the wireless relay.. we needed 12V. The boost circuit took the 4V and made it 12V. We could have built our own... but for the price, it can't be beat.

Other uses outside a skateboard:

1. Anywhere lights are useful, to be honest. In the home, garage, camping, on a bicycle, etc.

2. The circuit could be adapted to many other types of LED arrays for other wacky idea. Light wall, art instillation, etc.

The Skateboard Floodlights worked out great. As I skated around with them, I did in fact see objects on the ground and dealt with them as a skater would. The biggest save during filming was a few large potholes outside. I saw them due to the truck floodlights… I would have had to bail otherwise, or worse.

Originally, I wanted the everything to be packed into risers no larger than 3/8”. This way, I could take the board to the parks and use it normally. However, I didn’t want to limit an early design because of space limitations. Even as large as the ones used here, we still have space issues! Future versions could be exactly what I want. I could use a special flat-pack battery, and dense PCBs to handle the rest of the circuitry.

Despite all that… I think the Skateboard Floodlights are a perfect addition to cruiser and longboards. I always see them at night… and always cringe imagining flying off one - after hitting a rock. Oh… and, sometimes the skaters are hard to see at night… this is a great safety measure.