Recently, I saw a super cute little doll made with a dot matrix LED screen in a maker group. When there is sound, the LED screen shows animations, which is very interesting. Coincidentally, I have a dot matrix LED, so I decided to make one myself. I found that there really is such a thing on Instructables, called Lip Syncing Robot. The original version directly soldered the dot matrix screen to an Arduino Pro Mini, but the one I bought is driven by MAX7219. After looking at the author’s program, I tried to modify it for chip driving, but got stuck halfway [x_x]. I asked the author how to write the program for MAX7219, and the next day he replied. Now any Arduino can do it, and he left many pins available for adding new features later. Without further ado, let’s take a look at the images and videos below~Front view with cute expressionsSide view with logoBack view with switch

Effect video:

When there is music or sound, the expressions on the dot matrix LED screen will move. The louder the sound, the wider the mouth opens. If there is no sound, it won’t open its mouth to be cute, haha. If you play it with a small MP3 speaker beside it, the effect is even better [sneaky smile]. However, I later found that using a button battery for power is unstable, so it’s better to switch to a small lithium battery. After watching, don’t you feel a bit cute and want to make one, or perhaps make one as a gift for a girl or girlfriend? Below, I will share how to make it along with some program modeling files.

Parts:

8X8 Dot Matrix LED (MAX7219) (32mm x 32mm)
Arduino Pro Mini (other Arduino boards can also be used)
Sound Sensor
Switch Button
Button Battery (best to switch to a small lithium battery)
Dupont Wires (wires)
Shell (needs to be 3D printed)

I later added two hands, making it even cuter. The shell file has already included the version with hands. The shell file is modeled in Solidworks 2016, and I heard that SW files cannot be opened in lower versions. You can choose parts on Taobao yourself. The Arduino Pro Mini needs a USB to TTL module to download programs; you need to buy one if you are a first-time user. Find a 3D printer to print the shell file yourself.

Wiring Diagram:Just connect the circuit according to the diagram above, of course, you can also modify the pins in the program to connect as you wish. Remove the original pin header from the sound sensor; otherwise, it won’t fit into the shell. DIN—-D2 CS—-D3 SLK—-D4 OUT—-A4Program filesThere are two programs inside, one for the expression program and one for the lip-syncing robot program. After downloading and extracting, open the program with Arduino IDE and upload it to the Pro Mini to start being cute.LED-Matrix-EditorThis is an online tool for editing dot matrix LED patterns. You can change it to your favorite pattern and then copy the code into the expression program to modify the expressions.