Introduction: Doggie Dongle - LED Light for Your Dog's Collar

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We like to take our puppy Nala to the local park or golf course at night for a run around. Even though she is a white dog, she can be hard to see in the dark. You can buy a light for your dog at the local pet store for about $10 and it will work perfectly.

This is my attempt to make a homemade one for close to nothing and you can do the same if you have some tools and basic parts laying around.

Step 1: Stuff You'll Need

Tools:

  1. Hot Glue gun
  2. Soldering Iron
  3. Wire cutters
  4. Needle nose pliers
  5. Awl
  6. Drill with different sized bits
  7. X-acto knife
  8. Helping hand vice
  9. Sandpaper
  10. Safety Glasses

Parts & Supplies:

  1. Solder
  2. Solder tip tinner (Optional)
  3. #22 insulated wire
  4. A small clear plastic pill holder
  5. Heat shrink tubing
  6. Electrical tape (optional)
  7. 3V button cell battery
  8. Small carabiner or detachable key ring
  9. Extra small key rings (optional)
  10. Velcro (Optional)
  11. Small picture hanging eye with screw thread
  12. 3 to 5 MM LED (Red or other color of your choice)
  13. Small sliding switch (SPST or SPDT)

Step 2: Prepare the Pill Container

  1. Wash out the pill container and clean off any labels with hot water and soap. (To make sure Fido is not exposed to any medication residue).
  2. Sand the outside of the pill container until it is opaque (To diffuse the light from the LED)
  3. Drill a very small hole in the centre bottom of the pill container as a pilot hole for the picture hanger eye. Then screw in the picture hanger eye and make sure it is secure.

Step 3: Prepare the Circuit

The Circuit is super simple, just a 3V button cell battery, a switch and an LED in series as shown in the diagram. The button cell should last a long time as long as you turn it off when not in use.

To make this:

  1. You can either solder one leg of the LED to the battery or solder a wire to the LED leg and use electrical tape to fasten it to the battery.
  2. Decide where you want to place the switch (I placed it on the bottom of the pill container). As your battery and LED will be glued to the pill container inside lid, you need to make your wires long enough to reach the switch location from there. So make your wires at least as long as the pill container plus a little bit, you can always cut them later and this will accommodate any switch location.
  3. If you decide to solder the LED to the battery, first rub the battery surfaces with sandpaper to roughen them up.
  4. Tin the end of the wires, LED legs and switch terminals first (This means melt some solder on the ends of the wires and terminals.)
  5. Use the solder tip tinning compound (flux) on the soldering iron tip, this will help clean the tip and battery surface also.
  6. Before soldering, determine the correct polarity for the battery and LED. To do this simply touch the LED wires to the battery until it lights. There are only two possibilities.
  7. When you solder the LED leg to the battery, MAKE IT QUICK. You do not want to over heat the battery especially if it is a lithium cell. WEAR SAFETY GLASSES while doing this just in case.
  8. Solder a wire from the other leg of the LED to the switch. Then solder another wire to the other switch terminal and either solder the other end of that wire to the other side of the battery or use electrical tape to attach it.
  9. Use heat shrink tubing to insulate the switch connections and wire to LED connections.
  10. When you are finished test the circuit, when you turn the switch on the LED should light. If not, you either have the LED polarity wrong, or a bad connection.

Step 4: Install the Switch and Circuit in the Container

1. Cut a small rectangular hole in the pill container to fit the switch slider control using the exacto knife. This should be just large enough for the switch slider to slide back and forth and no larger. Here I placed it on the bottom of the pill container and I used a very small switch so that there was no possibility that the doggies movements would turn it off.

2. Put the switch in place and then glue it in place using the hot glue gun. Clean off any excess and ensure the switch slides freely and is properly positioned before the glue dries completely.

3. Glue the button cell and LED to the inside of the pill container cap. These should fit quite nicely and you can bend the LED leg so that it is roughly in the centre with respect to the cap so that it will be centred when you put the cap on the container.

Step 5: Install the Carabiner or Detachable Key Ring and Finish

Complete the build:

  1. Next put a small key ring through the picture hanging eye screwed into the bottom of your container.
  2. Next attach your carabiner or detachable key ring.
  3. Next Place the cap on the pill container body.
  4. Switch on your Doggie light and you are done

Final notes:

I found that the carabiner or detachable key ring hanging from the dog‘s collar ring were too long and that the light swung around and bothered the dog. My dog actually grabbed the light with it‘s mouth. So the lesson here is use a very small pill container and carabiner.

You can try placing the carabiner right around the collar itself and not the collar ring to shorten things. Alternately, you can try using some velcro or rubber bands to attach it to the collar. Here you need to get creative. The intention of this instructable is not that you will build it exactly as I did, but that it will serve as a template for you to work with and make your own modifications. I‘ll leave you to it...