If you haven’t read Part 1 of this purse project, start here to see how I tested the LEDs and created the initial circuit Interior Purse Lights – Part 1
Sew In A Switch
Once I confirmed the circuit between the Gemma microcontroller and the LEDs was working, the next step was to attach the hook & loop pieces to act as the switch. When the purse is open, the LEDs should turn on; when the purse is closed, the LEDs should turn off. After lining up the pieces on each side of the purse, I marked the location to remember where to sew each one. Using a new length of conductive thread and referring to the circuit diagram, I started at the ground (GND) again and stitched over to and around the hook piece (the scratchy one) that was placed on the same side of the purse as the sequin LEDs. For the other side, using a new length of conductive thread, I started at the D1 pad on the Gemma and stitched across the side seam of the purse’s fabric liner, to the marked location where I stitched around all four edges and attached the loop piece (the fuzzy one).
Time For A Test
At this point, it was time for another test. The final project code was included in the instructions from Adafruit, so I uploaded it to the Gemma after connecting it to the laptop again with the USB cable.
I used an alligator clip to close the circuit, so that I could see clearly when the LEDs were on or off. During the first attempt, the LEDs turned on correctly – stayed on while only one end of the alligator clip was attached to the fuzzy side, and turned off when touching the other end of the alligator clip to the scratchy side. However, the LEDs did not turn back on again, when I removed the clip from the scratchy side.
After messing with it to try and identify the problem, I thought maybe the circuit was too loose. The connections made between the components with the conductive thread were not stable enough. I added some stitches with regular cotton thread to better secure the Gemma to the purse lining, and it was more responsive. (If you look closely, you can see additional stitches on the pads along the right edge of the Gemma in the video that are not there in Figure 2.1.)
Success! After this test, the last remaining step was to remove the USB cable for power, and attach the battery pack. Unfortunately, when I tried the same test, I had a problem again. The LEDs would turn on at first, but would turn off when just one end of the alligator clip touched one side of the Velcro.
Power To The Purse
Still not stable enough. At this point, I ripped out the stitches and redid them to make them smaller, so the thread was not so loose. I removed two of the LEDs. I attached a pair of AA batteries instead of a double coincell battery pack. It’s still not working every time.
The only way I can get it to behave consistently is to attach it to power through the USB port. So, as long as I carry my laptop along with my purse when I go out, it works great! Seriously, I’ve got a few more things to try, including redoing the project with a purse that is not a soft bag, but has more structure like a leather or vinyl bag.
In the meantime, I hope you enjoyed reading about my electronics learning adventure! If you’re interested in learning what I’m reading and watching to inspire my next learning adventure, subscribe to my newsletter.