Breadboard layout for LCD & 8 buttons with Repetier firmware

Hi
I have created a breadboard layout for using 8 buttons and a LCD screen with Repetier firmware.

I wondered if someone could validate this layout as being correct? I am planning to create a PCB if this is right so I'd better get this right up front!

I am not sure if I need 8 x 1k resistors for each button - maybe they could share 1 pulldown resistor instead of 8 separate resistors?

Any other feedback is welcome!

TIA

Hi,

I have a similar layout for my gen6. I don't have resistors for the keys. In this case they are not really needed. The PCF8574 have internal pullups and pulling them down to GND doesn't hurt.

Check you board with and without the pullups to scl/sda. Some boards have them already included on their board so they maybe they are also not needed. If you see your display with and without pullups I wouldn't use them.

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Thank you very much for the feedback.
I have tested and confirmed that the pullups for SCL & SDA are needed with my Sanguinololu 1.3 board.
Here is an updated breadboard image in case anyone else finds this useful.

Do you have schametics for this breadboard? I want to make a pcb and having dificulties to understand the tracks.

Did you ever finish this?

Peter

Whassup, guys,

(i'm the "Guilherme" who asked here before)

i remade ANOTHER_REPRAPER breadboard refered before in this thread and made a pcb for it, putting my lcd display attached in the top of the board, and also put the sdramps circuit in the bottom area of the board. The board is made to connect into the gen7br2 witch design is available at [reprapbr-ge.blogspot.com.br] (in portuguese)

The link of the files (fritzing format) is in

[samuraieffects.com.br]

feel free to mail me at guilherme.henrich@gmail.com regarding this.

Cool, good work.

I tried to make a pcb in fritzing but I never finished laying it out or testing it. Attached is my attempted fritzing file for anyone who might be interested.

That's a more elegant and small design. I had some goals in my design:

-to make and all-interface-in-hole board

-to make the board with off-the-shelf copper boards, without cutting - i don't see anything more standard than 10x10 cm boards.

-to keep the board single face and easy to etch and solder (i.e. no smd parts) - unfortunatelly, i had to use some wire jumpers and.... four through hole pads would be bigger than a microsd card, that's why you won't find a through hole mount microsd socket (lol). If you find a good one off-the-shelf, let me know.

In the link, you can have my design files, so play with it and let me know any news.

Sorry to have reliven this thread, but has since made a lot of progress over in the new thread here:

[forums.reprap.org]