# Circuit building project - New to this (sorry)

#### K1ng

Joined Sep 7, 2019
3
Hey first let me start by saying its 6am and haven't slept been busy researching n stuff (please -polite terms only-moderator) lol. But i'll try and make sense i'm 19 and i'm very interested in making small mini projects and one of them is making a homemade mouse and i want to start by learning one part at a time starting with a scroll wheel so i was going to ask does anyone know where you can build a circuit board and put it together then if its all good get it made?
Sorry if that made sense hopefully when i'm actually awake i'll be able to fix it up thanks

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#### dl324

Joined Mar 30, 2015
8,974
Welcome to AAC!
Hey first let me start by saying its 6am and haven't slept been busy researching n shit lol.
There are members on this site from around the world. My advice is to be in the proper state of mind before posting.

i'm very interested in making small mini projects and one of them is making a homemade mouse and i want to start by learning one part at a time starting with a scroll wheel so i was going to ask does anyone know where you can build a circuit board and put it together then if its all good get it made?
Whenever you contemplate a project, you should perform a buy vs make analysis. You're attempting to reinvent 45 year old technology. You won't be able to make one or a hundred for less than you can buy them. If you want to learn how they work, that's fine. But making them won't be economical. You can buy them second hand for a $2-3; new for not much more. #### SamR Joined Mar 19, 2019 1,196 Study the history of the mouse. It was basically an X-Y axis joystick with a N.O. contact button. How does it interface with the operating system? Go from there... Thread Starter #### K1ng Joined Sep 7, 2019 3 Welcome to AAC! There are members on this site from around the world. My advice is to be in the proper state of mind before posting. Whenever you contemplate a project, you should perform a buy vs make analysis. You're attempting to reinvent 45 year old technology. You won't be able to make one or a hundred for less than you can buy them. If you want to learn how they work, that's fine. But making them won't be economical. You can buy them second hand for a$2-3; new for not much more.
money wise doesnt bother me and at the moment i want to just focus on the scroll wheel learn how to make one, put it on a circuit board then program it to get read if you know what i mean

#### narkeleptk

Joined Mar 11, 2019
374

#### DickCappels

Joined Aug 21, 2008
5,899
You may want to take apart a mouse with a scroll wheel and after studying it for a while build your own scroll wheel and connect it to the mouse in place of the original. That way you only have to master one part at a time. Otherwise you might have to study years before getting things working. One step at a time, easy as it goes...

#### cmartinez

Joined Jan 17, 2007
6,471
money wise doesnt bother me and at the moment i want to just focus on the scroll wheel learn how to make one, put it on a circuit board then program it to get read if you know what i mean
Google "optical encoder" and see what images pop up. That will give you a fairly good idea of how the scroll wheel works. The big challenge here is to properly interface the wheel you're trying to build to the computer. It can be easily done using very few components, but I'm not sure it would be the best approach for you to start learning things.

#### K1ng

Joined Sep 7, 2019
3
Google "optical encoder" and see what images pop up. That will give you a fairly good idea of how the scroll wheel works. The big challenge here is to properly interface the wheel you're trying to build to the computer. It can be easily done using very few components, but I'm not sure it would be the best approach for you to start learning things.

i suck at programming but i have a friend that'll help on the programming side im interested in the physical side

#### DickCappels

Joined Aug 21, 2008
5,899
If you start with a working mouse you can leave programming until the end, and then only if you want to.

#### atferrari

Joined Jan 6, 2004
3,465
i suck at programming but i have a friend that'll help on the programming side im interested in the physical side
I took the pain to teach my micro to understand and communicate using the PS2 protocol. That means understanding/speaking it.

Dare to said that I managed to draw a quite good graphic where timing is well explained. When reaching home I will try to retrieve it and repost it here.

I am genuinely afraid that in trying to reinvent that wheel, you will waste a precious (yours) time.

Buena suerte.

#### bertus

Joined Apr 5, 2008
20,070

#### atferrari

Joined Jan 6, 2004
3,465
Here you have it, just in case you intend to follow the PS/2 way.

One word of caution: after few tests I realized that to communicate with a micro, you need to power the encoder well after your micro was initialized. Why? Because if connected to the PC, when this is powered ON, the encoder sends immediately the warning "here I am" to start communicating with who is in charge (the PC).

I am adding the datasheet of the encoder I actually used plus the pinout of two different ICs. Hope you understand the difference between pull up and pull down resistors.

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#### Sensacell

Joined Jun 19, 2012
2,450
<RANT MODE: ON>

I would find this project extremely unsatisfying myself.

The cool part is learning about incremental encoders and position tracking- this part is relatively simple and totally useful.
But the other 99% of the work is figuring out how to get the computer OS to connect and function, this part is going to be hard.

Modern interface standards (USB) are very complex, allowing things to "plug and play" is no easy feat.
Everyone takes this stuff for granted so nobody understands or cares how difficult it is to get this stuff to work.
The same thing goes for playing with audio CODECS - you can buy an MP3 player for $10 - but try building one from scratch... <RANT MODE: OFF> #### atferrari Joined Jan 6, 2004 3,465 <RANT MODE: ON> I would find this project extremely unsatisfying myself. The cool part is learning about incremental encoders and position tracking- this part is relatively simple and totally useful. But the other 99% of the work is figuring out how to get the computer OS to connect and function, this part is going to be hard. Modern interface standards (USB) are very complex, allowing things to "plug and play" is no easy feat. Everyone takes this stuff for granted so nobody understands or cares how difficult it is to get this stuff to work. The same thing goes for playing with audio CODECS - you can buy an MP3 player for$10 - but try building one from scratch...

<RANT MODE: OFF>
In my case, managing to get the micro to enter in complete communication with the mouse, consisted mostly in getting the timing right around each pulse. It was the first very serious use I gave to my Owon scope, capable to record pulse bursts for a later inspection.
I enjoyed the challenge.

#### cmartinez

Joined Jan 17, 2007
6,471
In my case, managing to get the micro to enter in complete communication with the mouse, consisted mostly in getting the timing right around each pulse. It was the first very serious use I gave to my Owon scope, capable to record pulse bursts for a later inspection.
I enjoyed the challenge.
Also, there are single-chip virtual COM port USB to UART converters out there that significantly simplify things.

#### ag-123

Joined Apr 28, 2017
40
these days you can make a high precision optical gaming mouse
the parts ADNS-xxxx are widely available on amazon, ebay, aliexpress etc, but most of them have some proprietary pin arrangement that don't fit perfboards or protoboards.
the ADNS-xxxx sensors are the actual chips used in many of the premium commercial gaming mouses. but making it from bare materials may lead you to custom designed PCB boards and custom mouse enclosure design that at least needs a 3d printer to do it right. and besides there are specialised optical lens parts that could be rather costly. modern mouses has components that can't be 'hand made' that optical sensor is literally a 8x8 64 pixels digital camera sensor looking at the desk !

you may like to google search to see if you can find diy mouse kits with basically the ADNS sensors, that may be the simplest way to get from making it to literally have a mouse that works! and one of the trouble is modern sensors sometimes have the sensor, the microcontroller and software and all embedded in that single chip, and it goes direct to usb to the computer. there is literally little to tinker with if we use such a chip

for the scroll wheel, don't try to make a mouse.
you can buy something like this
https://www.ebay.com/itm/5pcs-Rotary-encoder-with-switch-EC11-Audio-digital-potentiometer-20mm-handle/311425031956
and try something like this
https://howtomechatronics.com/tutorials/arduino/rotary-encoder-works-use-arduino/

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