Noob questions about building first pcb

[wolfEXE57]

Hello everyone!

I hope this is the correct place to ask, but I would like some help with designing my first pcb. Im quite new to mechanical keyboards and pcb design so I have a lot of questions as to if I'm doing all this properly but ill keep most of them brief. I want to keep my first creation rather simple only 4 or 8 keys at max but i wanted it to be split as it would be a learning experience for a keyboard idea that I have. which brings me to my first question...

Are the MJ-4PP-9 & PJ320A jacks the same? in my haste i ordered 6 pj320a's from keeb.io
and noticed after i purchased it that the part ive been using in kicad is the mj-4pp-9. ive been unable to find any library files for the pj320a and they look smmilar enough that i figured they would be the same in kicad.

second question, Do i have to do anything special to have the two pcb's be split? from what ive seen i have to connect the 3.5mm jack to vcc and gnd and then scl and sda, is that it or do I have to add something extra.

I followed a few guides and attempted my first schematic, did i place everything correctly? https://imgur.com/ZAsU8BB

Thanks in advance for looking over my weird questions.

[nevin]

https://github.com/keebio/Keebio-Parts.pretty/blob/master/TRRS-PJ-320A.kicad_mod
other parts
https://github.com/keebio/Keebio-Parts.pretty

two ways for the two halves to talk to each other, serial or i2c. both ways require a promicro or similar on both halves connected via TRRS cable. the other way is to wire it straight through (all rows & columns as wires between the two halves - like an umbilical cord) then only one controller is needed as you are just extending the rows & columns between the two halves with wires.

keeb.io has a lot of good stuff!

[wolfEXE57]

https://github.com/keebio/Keebio-Parts.pretty/blob/master/TRRS-PJ-320A.kicad_mod
other parts
https://github.com/keebio/Keebio-Parts.pretty

two ways for the two halves to talk to each other, serial or i2c. both ways require a promicro or similar on both halves connected via TRRS cable. the other way is to wire it straight through (all rows & columns as wires between the two halves - like an umbilical cord) then only one controller is needed as you are just extending the rows & columns between the two halves with wires.

keeb.io has a lot of good stuff!

I downloaded that repo and haven't been able to get it to work in the symbol library, i didn't see any .lib files to add the files into kicad.

Is the setup I have in my schematic serial or i2c? 

[nevin]

i'm not familiar with kicad, just saw he had the pad layouts in his repo. it might not be a "device" but probably just the pad footprint size/layout for the PCB.

they both work over TRRS but i2c requires (2) 4.7kΩ resistors
https://docs.keeb.io/iris-build-guide/#solder-i2c-resistors-40optional41

[wolfEXE57]

Ok I think I figured out the kicad library issue. you just kinda place down generic items and then fill in exactly what they are later.
I was hoping if someone could take a look at what I have so far on my pcb to see if everything is correct? https://imgur.com/j1OqVN7

[ErgoMacros]

Hi. I don't get what your SW_Push is for. I as expecting a reset button, but your switch is connecting power (VCC) to ground.

[wolfEXE57]

Hi. I don't get what your SW_Push is for. I as expecting a reset button, but your switch is connecting power (VCC) to ground.

Was supposed to be a reset button but it appears I incorrectly read a post online talking about it. Its supposed to be the RST and GND correct?

[ErgoMacros]

Reset pin goes to 10K resistor, and that goes to VCC
Also... Reset pin goes to switch, and the other side of the witch goes to Ground.

Code: [Select]

Reset----------+-------10KR------VCC
                 \
                  \
                   +-----/   \----GND
                         switch
[/font]

[marhalloweenvt]

Ok I think I figured out the kicad library issue. you just kinda place down generic items and then fill in exactly what they are later.
I was hoping if someone could take a look at what I have so far on my pcb to see if everything is correct? https://imgur.com/j1OqVN7

First look into your setup, it's I2C. But you miss 2 4.7k resistors between D0, D1 line with VCC pin. For more information about I2C and Serial wiring, please have a look in this https://github.com/qmk/qmk_firmware/tree/master/keyboards/lets_split. You can use whatever suits your need.