I’m currently building the scottogame for my son and learned a lot in the process. I’m super interested in the next PCB video and expanding my knowledge to that next step.
Here it is... the first video in the PCB series. This information is essential to be successful in designing a PCB but once you know it, you're 90% of the way there. I'm sure some people will have questions, so feel free to ask! I'm currently getting ready to release the second video in the next few days, I just have to finish editing it.
Hey just came across this playlist. Can't get enough of it. I did have a question in regards to the pinout on this micro controller and any other micro controller. How do you figure out which pins on the controller go to a certain switch on the pcb ? Like why is S3 -> PD1 and not another pin?
Not sure if one of my headphone's battery died, but I'm only getting audio out of the left channel. If you recorded in mono, remember to double it to both left and right channels. This content is awesome!!! I'm really excited about building my own.
If I understand this correctly, a matrix should have issues with multiple keys being pressed at the same time, right? So if you press 0,0+1,0 and then add 0,1 the board wouldn't know if you added 0,1 or 1,1 right? Because row 0 and 1 are already active the board won't know which circuit was closed now since they're on the same column. It won't short because of the diodes, but it cannot really know what happend then right?
It will know every key pressed. lets call the 3 column A B C. and the 3 row are 1 2 3. In this case you presses the A1 A2 and B2 key. there are pins that can tell wether you activated 1, 2, 3 they are independent of each other. Now the trick is that voltage is only applie at one column at the same time. First you apply voltage to the A column. 1 and 2 will active. then you apply voltage only on the B column 2 is active. last you apply voltage on C column this time nothing has recieved any signal.
@@karelissomoved1505 Ohh, so it's basically scanning the matrix regularly? I thought it'd apply power all the time and basically instantly see when a switch is closed. But that makes sense that not all rows and columns always have power.
No resistors needed, just buttons and diodes. The diodes allow you to create a matrix with more buttons than you have pins but if you only needed 4, you could leave out the diodes and just direct wire it.
My mechanical space bar is broken: •If I touch the 2 pins its temporary fix it •the Switch bark works normal •But it will break down again if I not use the space bar for a few secs •Try to resoldering it, but its break again in the next day. •Try to replace the switch with another switch, its works fine but again same problem, its break down again in the next day. •The only solution for me is to touch the 2 pins with my finger while tapping the space button. •what is going on?. I dont get it.
I’m not sure I fully understand how the controller understands which key is pressed on the matrix. Is it sending an impulse one column after the other? Would this mean that theoretically, a key press could be missed if pressed between impulses? Does it consume more energy than a direct wiring?
Basically that’s why we use diodes. The columns send a signal one after the other and the rows are all listening for them. For building a board it’s not super important to know the specifics but the docs do a really nice job explaining in detail: github.com/qmk/qmk_firmware/blob/master/docs/how_a_matrix_works.md
I do not know how the author of the video will do it. But if the algorithm (code) of sequential "polling" of each matrix cell is applied, then you can hold down any combination of buttons at any time and it will work correctly. I recently started learning how button matrices work and this is a very optimized way to create keyboards. Before that, I used a multiplexer to get more inputs. But now you can connect everything together and the multiplexer can work as "columns" and arduino inputs as "rows". This will give a matrix with more buttons.
