Rear Windshield LED Display
have you ever wanted to have an led display with a dynamic text , have you ever wanted to talk with the driver right behind you telling him to stop honking or lowering his headlights down , have you ever wanted to make a dynamic ad on your car instead of a paper one , this project is right for you , plus this project is just a concept of an idea ,There are numerous potential upgrades for this product. , and as much use cases ,
so if you are interested , stick around , and I'll guide you step by step , by giving you free resources on how to build this project
everything is ready , I did the hard part for you , you just to apply the steps
Supplies
first of all
you need to buy all the parts that are on the sheet given below, I provided the links to every part , you just have to copy and paste
-on the link below you can find the Gerber files of the boards, just download them, and order your PCBs from whatever supplier you want
(by the time you download the board schematics, or the components list you may find some slight ramifications, but nothing to worry about, just a few improvements, and the functioning is the same)
if you are a professional and you know what you are doing and you're on a budget, you can make the boards yourself at home
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tools
- soldering iron for the through-hole components
-heating plate for soldering SMD components
-soldering paste
-tweezers
-pliers
-some wires
cults link :https://cults3d.com/en/3d-model/tool/rear-windshield-led-display
Downloads
Watch the YouTube Video
Watching the video is an excellent idea if you're a visual learner. And if you don't understand something, don't worry, everything is mentioned here and explained in detail
Let's Start by the Architecture
The brain of this project is the ESP32, which can be powered in two ways: either through a USB-C connector or a KF128 connector with 5V. However, be careful not to connect both power sources simultaneously, as this can damage the ESP32 or the entire board. I did not design a protection feature for using both power supplies at the same time, as it would cost more parts money time, and complexity.
Now, let's continue. The ESP32 has wireless capabilities like Wi-Fi, which we'll use to communicate with the board via a web browser on our phone. The ESP32 will receive commands from the browser and send them to the LED matrix driver chips to display the desired message.
To upload the code, the board is equipped with a USB-to-TTL converter chip. There is also a boot button, a reset button, and a third button that can be used to store and change texts manually. This is a future extension depending on consumer needs.
If you want to explore the things I mentioned above in more detail, you can search for each topic individually to gain a deeper understanding of the circuit's inner workings.
Please excuse my handwriting, this photo was taken in the early stages when I was planning the project
now after you have an idea about the project and how it works , let's proceed
Put the Solder Paste
put the solder paste into the corresponding pads
you put too much and it can make a short circuit, put too little and you risk leaving the component unsoldered or untouching the board,which would result to random behavior sometimes , you have to put almost the perfect amount, my advice to you is either you order a stencil (which I didn't do)
or use a syringe of soldering paste with a small nozzle, like a 0.5mm nozzle
it will give you the best results (and gain those extra few dollars of the stencil)
Place the Components
one thing i can tell you is to recheck everything even 100 timer before placing and soldering the component , there are some components if you make even a single mistake, it will cost you the whole board, like once it happened for me, I shorted, the USB-C connector, and then I tried to remove it and it pulled the PCB traces with it, now I had no way to upload the code to the MCU, luckily this happened to me in another project and I learned from my mistakes.
these boards worked like a charm actually, and I was very happy with the results.
check orientation , check the values of the passive component, and put aside what you already placed on the board, so you don't get confused between components and parts that are already placed and the ones that are to be placed
Place the PCB on the Heating Pad
when placing the board on the heating plate, make sure not to keep it too long, or will mess up the bottom of the board, and always keep an eye on the components, don't put it and leave, sometimes the components get pulled to the side, when the solder is not placed evenly they get dragged to the side that has more paste
see in the picture my heating plate is smaller than the board I am soldering, so it takes more time, and I need to solder it in stages, so sometimes, the components get soldered and then melted and resoldered again, so my advice is to use a bigger heating pad for best and fastest results, otherwise you can work with what you got if you are skilled enough
Testing
this is an essential step, and the more important is that you should do it before running power through the board, this way you can fix any issue before you see that magic smoke
Button and Through Hole Components
these are the easiest components
these are for amateurs normally you can't miss, or make any mistake whatsoever, if you are already past the SMD stage components.
by the way, in this board, you see that I am soldering no KF128 connector because I decided to use only USB as a power source, I just made one board with the external 5v input which you can find on the YouTube video, that was just for demonstration purposes
again all necessary files, schematics,3d files are found at this link: https://cults3d.com/en/3d-model/tool/rear-windshield-led-display
The Threaded Nuts
for placing these threaded nuts, they're inserted by heating them and putting them in their corresponding holes
best practice is to use an old soldering iron so you don't mind it being corrupted by melted plastic , and you insert them
if you have a 3d printer, just make sure you tune your settings so the holes can be perfect
if you don't have a 3d printer you can outsource the parts
you can find the STL files for the case below
I Made a Small Batch
you can do whatever you want, by the time I took the picture I made only 4, in the video, I will be showing you one more
so they're 5 in total
Closing Up
after printing the palstic housings, soldering the parts to the board, and testing and checking if everything is in place, now it's time to do the most rewarding task, the finish, closing everything up, and testing our final product
seeing the beauty of our hard work
Upload the Firmware
the best thing about this project is it can be repurposed, by just changing the code, you can use it as an LED display for your car, for having fun with friends or for business purposes, or it can be used for small shops, like communicating with customers or displaying some news like if you're a bar owner you can say (for the next hour there's a30% discount on the beer)
or if you know C/C++, you can recode the display and make it a wall clock, or connect to whatever wifi connection, and display whatever information you want like, a weather station, or some news from whatever channel, or whatever info you think are important for you and your surroundings
again the code , schematics and all of the files are found at this link:https://cults3d.com/en/3d-model/tool/rear-windshield-led-display
Congratulations
Congratulations, you did it! For the upper threaded nut, I added a car vacuum suction cup so you can hang it on any soft surface you like. You can even hang it upside down or mount it on a tripod—just remember to adjust the code accordingly. Or, if you prefer, you can use it as is without any extra accessories. The choice is yours!
for example, you can use it as an ambient light in your videos
Be Creative
Feel free to get creative! You can adjust the font size in your web browser—for the big font size if the text gets too wide, it’ll automatically scroll. To start, just type the IP address of the ESP32 into your browser, usually 192.168.4.1, and you will land on its web interface,and type whatever comes to your mind
So go ahead, have fun with it! Write some funny sentences, and even make a few call videos. Don't forget to share them in the comments so everyone can enjoy them!