"Lumi Lock" Messenger Bag

Introduction: "Lumi Lock" Messenger Bag

 The "Lumi Lock" is a light/lock messenger bag, that highlights safety and convenience. 

This tutorial is divided into two parts:

A) Cutting and sewing the pattern for the chain strap.
Wiring the electronic components into the existing bag.

1. First you will need some materials in order to make the pattern for the shoulder strap, this strap will be a cover for your chain lock.
  a )Have a large size format thick paper, (Poster Paper works best) Scissors, ruler, fabric marker and a pencil
 For the the padding you can use upholstery foam, the firmer the better.
2. Pick your fabric, using a waterproof material will be best. However, for this project I would recommend heavy-weight cotton blends or canvas.
3.Follow the given measurements to make shoulder strap. Use pencil to draw the measurements on the paper. The measurements are from a standard KON chain lock.
(Measurements might vary given the KON chain lock you have. These measurements are for a -- KON chain lock.) You can simply add to the length and keep the width the same.
4. Once the pattern is drawn out you can now start to cut the pattern.
5. Place the cut pattern onto the fabric and trace along the edges of the cut pattern. Tip: Use a marker that will show after you have traced the edges of the pattern onto the fabric.
6. Cut outline pattern, and make sure to allow room for error if your not an experience sewer.
7. Iron the cut fabric and make sure to iron the flaps at dashed lines for easier sewing.
8. Now you are ready to sew. Place fabric inside out like shown.
9. Sew three out of the four sides, this will leave space to slid in the foam padding.
10. Once done  sewing you can invert the fabric and slip in the foam padding through the open side making sure the padding is align to one side of the pattern, you can use an invisible stitch method to close the edges.
11. Use the sewing machine to sew the folded fabric padding, and then invert again so you get a clean look.
12. Now that you have sewn the edges and inverted the sleeve you can clean up any rough edges.
14. After setting this up now you can focus quickly on sanding down the connections between the bag and chain. If you conductive metal you don't have to worry about this step.
15. Make sure to have a strong connection between the connectors Example End Chain links and Bag hinges. After everything is sanded check with the Digital multimeter. 
16. Once all that is ready to go, run a flexible wire from the ends of the chain links so it connects both ends of the chain. use electrical tape to secure the wire. 
17. Now that you have that ready to go, simply slip the final sewn shoulder strap over the chain and you are ready to go!

B) To begin find a messenger bag that you like and would want to add more visibility to your daily commute.

1. You will need an utility knife, sewing needle, if you are using leather you will need a leather sewing needle or kit, heavy duty thread. marker, leather puncher, and ruler. These are mainly to be used for preparing the messenger bag.

2. You will need these hardware supplies and components:
 a) Arduino UNO or Adadfruit "Trinket" 
 b) 1wtt LED lights
 c) Rechargeable Lithium Ion battery 3.7v 6600 mAh (Don't forget the charger)
 d) Program code: Button example in/from the Arduino Library
 e) Wire: Think about the threading if you want flexibility or rigidity. 
 d) Utility knife
 e) Red marker to change the LED color to follow with Cycling regulations. If you can get red LEDS then simply do that.
 d) Sewing thread and needle. To secure the board onto the messenger bag.

3. First write the code and program the Arduino.
Code used:


// constants won't change. They're used here to
// set pin numbers:
const int buttonPin = 2;     // the number of the pushbutton pin
const int ledPin =  13;      // the number of the LED pin

// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status

void setup() {
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);     
  // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT);    

void loop(){
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed.
  // if it is, the buttonState is HIGH:
  if (buttonState == HIGH) {    
    // turn LED on:   
    digitalWrite(ledPin, HIGH); 
  else {
    // turn LED off:
    digitalWrite(ledPin, LOW);

4. Test the connections with alligator switches.
and trouble shoot the code.
5. Solder the components together, after making sure everything works.
Make a pattern for your LED’s (Pattern can change given the dimension, style and material of your chosen messenger bag.)
6. Mark your bag with your sharpie to indicate where you will be placing the LED’s.
Align the LED to the given pattern, to make sure that the LED’s will fit properly.
7. Make sure to cut through the leather or fabric using the utility knife and leather puncher to allow for easy placement.
8. Place the LED’s into the plotted and cut bag.
9. Sew the fabric once everything is in place.
10. Place the Arduino in a pocket if available or sew carefully into the side of the bag (if possible)
11. Make sure the battery is attached to the Arduino and sewn into the inside of the bag or placed into an existing pocket.
12. Test that everything runs smoothly and Get ready to ride and be seen!

Be the First to Share


    • Audio Challenge 2020

      Audio Challenge 2020
    • Maps Challenge

      Maps Challenge
    • Backyard Contest

      Backyard Contest



    6 years ago on Introduction

    I don't get why you need an arduino when you already have a switch and a battery.