Trying to make test board with an Arduino UNO

Hello guys,

As i have a bit of free time and wanting to learn Arduino Basics i thought “Why not make it a complet projekt?”. Which is why i wanted to use elektroniks, mechanics and programming. For the start wanted to build a test board where i do not have to always make new curcuits but use one main curcuit where i have many options always at use. After that i wantet to use my 3D printer to make the housing and so on. After all that will (hopefully ::slight_smile: ) come the programming.

For now I have finished the generall curcuit using a Arduino UNO and various parts i have avaible. The current version is in the attachemnt. I used TinyCAD to make the curcuit, so the symbols can differntiate form the correct ones as I had to make some of them myself.

My main questions for this post is if i have made any mistakes or if u have a better solution for some of used parts (please to tell me about it maybe I can use some of them if I have the part at home).

Best regards,


I already made a small change which is including an ON/OFF switch with a green 20mA LED (and and 580 ohm resistor since it would be conected to 12V DC). As this is only a small change and not so important for the main curcuit I will not post it again. ^^

As an addional infomation (may be of use if u have new or better ideas thought I dont think so):
After the general curcuit is finish I will start to make an curcuit for the assembly board (completly selfmade). I will not solder any of the components directly to the UNO. Currently, I am planning to use normal jst pin which connect will connect both boards.

This looks like a completed project. Not a foundation for building more projects.

If I was building this, I would try to keep both the SPI and I2C buses open. Then I can plug in new sensors or other chips. You have most of your SPI wires tied to the stepper motor and the I2C wires tied to the LCD. Maybe use an I2C display and free up at least some analog pins for future analog inputs.


Thanks for the reply. My main idea behind this is, so i don't have to change the parts over and over again.
I want to make it so that it is like a complete projekt with the option to just unplug all I/0s if I am ready for more complicated programming. And if I am ready to programm advanced programm then I planned to buy an Mega2560.

At the moment I plan to use my 3D printer to make a housing where I just have to plug the UNO in and close the housing.

But if there is a way where i can keep the parts I use and also free a few Pins then I would be more than just happy. If I have more pins free i would also be thinking about your opinion (but maybe would also just add more or other parts)