F2 Conditional Diaper Purse




Design and technology merge to create a twice-functional diaper bag that will serve to illustrate useful reminders on what's missing and what's accounted for before setting out for the day. This stylish bag will use fabric switches that will trigger five or six LEDs, which will reflect the current conditions of the bag, whether half full or half empty. You'll never be without your essential baby items: diapers, wipes, bottle, bibs, food, binkies or, in my house, a most-important iPad. The soft-light LEDs will display a gentle reminder to restock on items that may be missing. You'll never leave home without having exactly what you need to make your baby, a happy baby.

Purpose: Create a multi-functional bag that creates space-holders for specific baby or child items. Generate an interactive reminder for items that need restocking or essential items you can't leave home without.

Design Intention:
  • Be the coolest mom on the block with a custom-designed, cool-looking diaper bag with interactive components.
  • Item-specific input pockets: bottle or sippy cup, iPad/changing pad, bibs or binkies, phone or forks, diapers & wipes
  • Generate item input responses with fabric switches and LEDs as a second function of the bag itself. LEDs will be On when items are missing and Off when they're not. 
Materials: Fashionable outside fabric for hip moms who prefer to look chic. Ripstop lining for the inside. Lilypad Arduino, 5 LEDs, 1/2 webbing, 2" webbings, conductive thread, Lilypad power supply, 5 metal snaps, 24 gauge wire, 1/4" elastic, velcro tabs, 1 or 2 12-14" zippers, heavy duty and medium weight interfacing

Step 1: Cutting the Pattern

For the purpose of this bag, it's important to start with the outside materials and start building before working on the inside liner. Although, you could cut the pieces and assemble them as you go along. The pattern was made from interfacing which is easy to use and allows for repeated use. Select the fabric to use for the outside, something that seems durable, thick and easy to wash if necessary. If the fabric has a specific pattern, stripes for example, be mindful of the direction of the pattern and your cutting in relation to the desired end product. If you have the right interfacing, you can also use the pattern for the outside to strengthen the fabric if need be. Cutting all pieces at once is useful, then you can just start assembling without stopping to cut or measure. After you have cut out the pattern, you can start to cut the fabric. The pattern is measured with a 1/2" seam allowance. Using pinking shears on delicate or easily-frayable fabric is helpful. For the outside, you'll need to make sure you have the following cut:
  1. Back x 1
  2. Sides x 2 
  3. Side Pockets
  4. Front x 1
  5. Front zipper pocket (optional) x 1
  6. Bottom x 1
  7. Strap Fabric x 2
  8. Strap Webbing x 2
For the liner you'll need to following:
  1. Back x 1
  2. Back Pocket x 1
  3. Sides x 2 
  4. Side pockets x 2 
  5. Front x 1 
  6. Bottom x 1
Medium weight interfacing:
  1. Front x 1
  2. Back x 1
  3. Sides x 2
  4. Zipper pocket x1
Heavy weight interfacing:
  1. Front x 1
  2. Back x 1
  3. Sides x 2
  4. Bottom x 1
Please refer to the PDF for a checklist of other pattern pieces or elements.

Step 2: Prep Work

After you get the pieces cut, you may want to do the tedious prep work so that your final assembly process goes smoother.  This means sewing applicable hems on the pockets for the elastic insertion and the top hems for the outside pieces.  The extra 1" on the top of the outside will be folded down to hide wiring and therefore, to create a finished look, you'll want to have a hem on the bottom.  You can also attach the zipper to the front pocket and have that ready to attach as well.  You could also do the top zipper if you're creating a zippered top as well.     

Step 3: The Straps

After you have cut the fabric for the two straps, you can fold the material in half, inside out, and sew a 1/2" seam using a straight stitch. You will end up with a bit of a fabric tube that you can turn so the right side is facing. Shift the tube just slightly so the seam is on the bottom and slide the webbing into the fabric tube. You do not have to make straps out of the fabric if you want to just use webbing or some other kind of strap. Each 24" strap will give you 1" on each end to sew into the top and bottom of the bag. You can measure how long you'd like your straps to be (I choose 22"). You can cut the additional straps down just slightly if necessary. You could also make adjustable straps but that takes some additional steps not covered here. 

Step 4: Preparing the Sides for the Pockets and Switches

The pocket  sides of the bag can be sewn together at the bottom to get the process going but you'll want to wait before fully attaching the pockets to sew in the conductive snap/switches.  For the four sides (interior and exterior) you can just create 1/2" overlaps about 2" from the outside on the bottom portion to account for the extra inch of the pockets.  You can run a quick stitch to hold  it together.  The reason for doing this is just to give the pocket a little extra room for bottles or other objects.  The elastic towards the top is cut just short of 7" to give the top some closure.  This is nice to have to keep items more secure.  You can prepare all five pockets at this time.

Step 5: Preparing the Switches

For this step, you'll need a snap, conductive thread and 1/4" strap webbing (or something similar).  I used the strap webbing to eliminate fraying of the switches.  After cutting them, I melted the ends slightly with a lighter to prevent fraying.  You will cut these into 2" strips. Creating the LED switch is a 3-part process.  
  1. Attach the bottom of the snap to a side about 2" down from the top of the pocket using conductive thread.  Have the thread come through the backside and cut it off about 6" for wiring.
  2. Attach the top of the snap about 1/2" from the end of the strap using the conductive thread.  Once you have done this, place the snap together and extend the remaining strap facing towards the top of side.  
  3. Now, you'll make two stitches, one just above (2 cm) the top snap and another at the end of the webbing to secure it to the side.  Be careful of the snap while sewing!  (You could do it by hand, too.)
This is a very easy way to create the contacts that will trigger the LEDs. It is a bit of a "loose" switch because the LED is triggered by the snap making contact.  However, if you want to fully turn on or off the LED, you can just close the snap! You will need to create five switches for the five LEDs.  

Step 6: Adding Wiring to the Switches

The next step involves wiring the switches.  I used 24 gauge wire to make stronger connections to the Lilypad.  I first stripped a small end of the wire and wrapped it with a small plier to create a loop.  I soldered the loop together so it wouldn't slip.  Now, using the 6" remainder of the thread, you can sew the wire directly to the sides, making sure you have a tight connection on the loop.  In addition, I color-coded the wire so I could keep track; I chose green for ground and red for positive.  Again, you can repeat this process four additional times so you end up with five sides with pockets, switches and wires!

Step 7: Attaching the Zipper Pocket to the Front

The most important part of this step is to give yourself enough room above the zipper pocket to line the LEDs.  I initially had the pocket 6" above the bottom but it was just a tad too much so I moved the pocket down an inch.  The zipper pocket is completely optional.  You will measure the distance from the top you want the pocket and create a 1" hem.  Then, sew this hem upside down on the front of the bag so that when you fold it back over, it will be on the front.  You can secure the sides and bottom if you wish.  This might be helpful since it's so hard to sew the sides with such thick fabric.  

Step 8: Adding the Eyelets for the LEDs

Once you have the front piece with the zipper pocket attached, you can measure for the LED eyelets.  From either side, measure about 4" in mark the spot with a chalk pencil.  I spaced the LEDs 3/4" apart and lined them vertically but you could go across the bag as well.  Once you've marked the eyelet spots, gently create a very small tear in the fabric with a seam ripper.  Then, using your thread, you can sew around in a circle to create the eyelet.  I'm using the Lilypad LEDs, which are small but powerful.  My eyelets are pretty small.  However, you can also place less expensive LEDs right through the eyelet if you're not using Lilypad LEDs.  Repeat the eyelet process another four times.   

Step 9: Open Up the Backside for the LED Wiring

Once you've got your eyelets sewn, you can place the liner side of the bag against the outside and with a small pen, mark where the eyelets are on the heavy interfacing.  Once you've got the locations marked, you'll be able to see where they'll sit on the opposite side of the bag.  You can create a small window for the LED wiring and even cut the liner fabric to fold to limit fraying.  I sewed this liner directly to the interfacing to create the window.  

Step 10: Wire the Lilypad and Power Supply

At this time, you can do some preliminary wiring, with your Lilypad.  Again, I used wire for the LEDs to create better connections.  I soldered all LEDs and attached them to the Lilypad and then attached the Power supply to the Lilypad as well.  Next, I soldered two additional ground wires to the power supply for the switches and LEDs and sewed these in a line using conductive thread.  While this is also very time consuming, I found that the flexibility of the bag would cause the conductive thread to lose connection, hence, the wiring. Once you've got the wiring almost complete, you can think about adding a flap to the cover the wiring components.  This is also optional.  I secured the Lilypad and Power supply to the interior of the bag using a small, velcro circle.  

Step 11: Sewing the Sides Together and Attaching the Bottom

Now, you should have four bag sides, three with liners and pockets, two with outside fabric and pockets, 1 regular outside back and the zipper pocket with eyelet front.  You might also want to attach pieces of felt to the sides that will be touching one another with wiring.  While attaching inside to outside, to cut down on time, you can use 1" bias tape to run alongside the sides and bottom, connecting the inside to the outside.  The biggest problem in this step is having the right machine.  Since there are so many layers of thick interfacing, having an industrial or heavy duty sewing machine is a must.  Using the Bias tape while sewing the sides together eliminates the extra step of attaching it but can also be tricky since it slips easy.  Attach all sides together with the liner facing out.  (You should have two pocket sides (inside/outside) back to back.  You can also attach the bottom to the bag at this point.  

Step 12: Finishing the Wiring

Now that you pretty much have your bag together, you can finish up the wiring.  Just measure the approximate length you'll need and create the connections to the Lilypad and ground wires much like you did with the LEDs.  Once you've got everything wired up, you can turn the bag right side out.  

Step 13: Attaching the Straps, Hiding the Wires With the Hem

You're almost there!  The final step is to add the straps to the hem and then fold it over so that the wires can be tucked underneath.  The tricky part of this step is making sure you don't sew the wires too much so you want to keep them well tucked into the fold.  (I actually did't hem the front with the sewing machine because of the wiring.  A hand stitch would be best here.  I think I'll move the hem down an inch to really help bring the wires down and then it won't be as much of an issue.  This you'll have to play with.  You can attach the straps at the same time by folding it at the bottom 1" and placing it underneath the hem.  There may be better locations for the straps, honestly.  I might choose external straps next time or maybe do one across the length of the bag. Unless you're creating a zipper top or adding a magnet closing snap, you're done!

Step 14: Programming the Lilypad

If you have not done so already, you can program the Lilypad and test it out (which you've probably be doing the whole time anyway).  Just upload the program, flip the power and see if the bag works!  (I should mention that programming and wiring are tricky for this bag and it still needs some wrinkles ironed out.)   Good luck and enjoy!

Step 15: Lights, Camera, Action!



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    10 Discussions

    I really like your 'ible. It took me a minute to understand that (and correct me if I am wrong) each pocket has a self closing switch that lights a light when empty. Each pocket it intended for one specific item, so an empty pocket means that item is missing. At first I thought you were using RFID tags somehow, and I was really excited, but the simplicity of this makes it better.

    Since you said you are hoping to improve on the idea I thought I'd offer a suggestion. You could have a "soiled" item pocket that worked in the opposite way and alerted you in some way to remind you it is NOT empty. I would think (as I don't have kids) that a soiled pocket would be a must and forgetting to empty it would be an easy, ugly mistake.

    Great job. I look forward to seeing your next 'ible.

    Wouldn't it be easier to ditch the lilipad and go with a simple analogue circuit? Especially since all you're doing is having the LEDs turn on?  Sure, you'd use more thread, but it might be cheaper and more simple than using a Lilipad.

    Also, if you sewed in small magnets, instead of snaps, you could have your circuit automatically close for you when nothing is in there. You could buy some very small Rare Earth Magnets, only 100 for $10 off amazon, and put them behind your conductive thread on both sides of a pocket.

    A very cool idea overall.  I wish I could sew better so that I could make one as a baby shower gift.

    3 replies

    Reply 8 years ago on Introduction

    For sure. I have limited experience with the micro-controllers and the wiring concepts as whole so that aspect is new for me. I just happened to be working with Arduino in the class I built this for so I needed to implement an Arduino-concept into it. I had the magnet idea and bought some but the magnets I had would always keep the circuit closed with items that weren't holding it open, so then I thought about flaps, etc.etc. It's a bag-engineering dilemma as far how you want the pockets to work vs how the LEDs work. If I found smaller magnets it would have been better. That was my original intent. However, I suppose the snap gives you a bit more control over opening and closing the circuit so it's a bit of a toss up there. Thank you for your insight; I was trying to figure out how to build an analog circuit as you mentioned and it just dawned on me! So yes, ditching the Lilypad would be faster, cheaper and easier so thank you very much!


    Reply 8 years ago on Introduction

    If you'd like some analogue circuit help, just send me a message. I've only been at this whole circuitry stuff a few months myself, but will offer my basic circuitry knowhow to you in any way possible. (I keep thinking of ways to make random bags I have into "Tron" bags... he he he)

    You can always do conductive velcro, which would be more simple than the magnets but also (more or less) stay shut on it's own.

    As someone who is gaga over solar power you could always throw a solar panel in there somewhere (like one of those fancy flexable ones) to make it self charging. But that might be overkill....


    Reply 8 years ago on Introduction

    Gosh, thanks for the suggestion! That's actually a great idea because it's still a WIP for me. I think it has some great potential and I'd like to refine it for sure. (Design and technology). I really appreciate your feedback! It's an offshoot of other bags I've made...see pic. : ) Cheers!


    Reply 8 years ago on Introduction

    Thank you! I'm still working out some kinks but I'm glad it shows nicely. : )