Open Project: Prototype Zhiye Yang


In this final, my idea is to create a key chain to avoid collisions with people. In our life, when we are in a hurry, we will run in a hurry, and in this process, we will collide with each other because of people who walk too slowly in the street. Therefore, in order to avoid this problem, I created this alarm that can remind others or myself.


The idea this time is that the key chain can be hung anywhere in the body, such as the arm, the front of the schoolbag, the belt, and so on. When running or running too fast, there will be a red light. The red light means to remind the people around me that my speed is relatively fast, so I can avoid it properly. At the same time, I can also remind myself to pay attention to the passers-by and my speed to avoid any unnecessary collisions. When you collide with others, the key chain will flash white light. This light is to remind yourself and others to say sorry to each other in time.

The 4 points of wearability 

Detachable. Can be hung anywhere on the body. During the creation, considering that this product is a product used many times, the design form is a device that can be removed at will, which can be reused many times, and can also be matched according to different clothes and hung in different places; Durable. In the process of creation, I use materials that can be disassembled for washing, so that they will not be damaged when they are cleaned and used many times; Lightweight. In the design process, because it is about the items worn on the body, it is necessary to choose a key chain that can not feel the weight, so that the wearer can walk more freely; Beautiful. Because it is exposed outside the body and the position of clothes, I designed the lovely panda head when designing this product.


First of all, I sketched out the appearance, which is the appearance of a panda, and then sewed and edited it according to the materials. Other designs are the same as those in the previous proposal.


img_3795 img_3794 img_3793

Final Project Images

img_3803 img_3800 img_3799 img_3798

Parts List

glue gun
Sewing box
circuit playground express


Circuit Diagram


Reflections & Next Steps 

During the production process, I encountered many difficulties, such as how to fix the circuit and how much time the flicker is appropriate and will not be regarded as disturbing. When designing the collision, I hesitated about whether to add sound and finally canceled it because I thought that adding sound might frighten the other party. It’s not an altruistic work. When I have the opportunity to continue the production later, I want to add a few more steps to add the interest of the whole work, such as adding LED lights to the ears to add a lovely atmosphere, or adding a little light to the eyes, or making the production more streamlined in terms of switches.

Resources & Related Works 

Stephen. (2018, June 6). Natural disaster sensor project with Circuit Playground Express – tutorial Australia. Core Electronics. Retrieved April 22, 2022, from

Adafruit Circuit Playground Express – blocks / Javascript editor. Adafruit Circuit Playground Express – Blocks / Javascript editor. (n.d.). Retrieved April 22, 2022, from

Leave a Reply

Your email address will not be published. Required fields are marked *