[Pretending Artifact] Another Personalized Business Card V1.0

As an engineer who works hard on the front line, every time I meet with big bosses, they always hand over their business cards. Every time I receive a business card, I look at the title on it with envy, so I came up with the idea of ​​making a PCB business card. idea.

After searching on Baidu, there are quite a lot of business cards made by people in the past. There are all kinds of business cards, each with its own characteristics. I believe that your ability will speak for itself when you hand them over.

Some business card pcbs are as follows:

There are pcb rulers, minimal avr systems, linux systems, nfc, some are exquisite, and some are very high-end.

After searching all over, nothing seemed suitable for me, so I decided to make one myself.

Require:

   1. The thickness should be thin enough to be easy to carry;

   2. It must be cheap enough;

   3. The function must be practical enough.

I finally positioned my system to use a cheap enough microcontroller to implement an electronic keyboard. This would satisfy my identity and match my temperament.

After much selection, I chose WCH's ch55x. This microcontroller cost less than 2 yuan when I bought it, but now it costs more than 4 yuan.

The first step is to test the hole board:

Key device testing:

I selected a lot of the smallest buzzers and bought them one by one to test the sound.

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.672c2e8dqDidDi&id=543442729908&_u=4c8b88m1b62

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.672c2e8dqDidDi&id=44763119512&_u=4c8b88m1b94

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.672c2e8dqDidDi&id=43420894554&_u=4c8b88m3b90

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.672c2e8dqDidDi&id=634342562820&_u=4c8b88m96d5

In order to reduce the thickness of the business card, the USB interface uses a sunken micro USB.