After the first introduction of sewing a single LED on a piece a fabric, I first collected some materials that I need for my first assignment of LED embroidery. After collecting the LEDs and threads, I was trying to find an already-made object to sew the LED on. Eventually I decided to use one of the ugly hat I have and turn it to be an ugly Christmas hat with LED and the LEDs turns on when the hat sides are buttoned.
After putting one LED on the left side of the hat I was thinking about putting more on the other side just to make it different. However when I sew three LEDs together and connect with power source, they did not lit.
From there I decided to just only use the middle one as the functioning LED and keeping the rest two as decoration... After attaching the LEDs and sewing the connecting point onto the part of the hat to be the switch I added some conductive tape onto the buttons just to make the connecting surface bigger. Then it worked!!