Implementation for IO-Expanders

[PercyJW-2]

Currently, only MCP23017 Devices are possible, but I have tested the Implementation and it works

[sago35]

@PercyJW-2
Thank you for the PR. It looks good at first glance.

I have one question. I think the kbexpander.go is handling switches connected in a matrix to the MCP23017. Is the source code based on kbmatrix.go?

[PercyJW-2]

Exactly. Sent from Proton Mail Android

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On 7/30/24 17:02, sago35 wrote: ***@***.***(https://github.com/PercyJW-2) Thank you for the PR. It looks good at first glance. I have one question. I think the kbexpander.go is handling switches connected in a matrix to the MCP23017. Is the source code based on kbmatrix.go? — Reply to this email directly, [view it on GitHub](#44 (comment)), or [unsubscribe](https://github.com/notifications/unsubscribe-auth/AMOCQA365LAZHEZ6DSQ6TWLZO6TKFAVCNFSM6AAAAABLSZK6VSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDENJYGU3TENZVHE). You are receiving this because you were mentioned.Message ID: ***@***.***>

[sago35]

Is there a reason you are using Pullup here? I think the PR can be merged as it is now.
Depending on the reason, it might be necessary to create a PR in the future that allows for selecting either Pullup or Pulldown, including for kbmatrix.go.

I have one more request. Could you share the expected circuit diagram? kbmatrix.go assumes the following. I assume it's the same circuit, just differing in whether to use pullup or pulldown.

https://kicanvas.org/?github=https%3A%2F%2Fgithub.com%2Fsago35%2Ftinygo-keyboard%2Ftree%2Fmain%2Fkicad%2Ffric10key%2Ffric10key

[PercyJW-2]

I used pull-ups, because the mcp has no pulldowns and on a schematic level it's the same, just with rotated diodes. I currently don't have a correct schematic, as I soldered all diodes in reverse direction according to my schematic Sent from Proton Mail Android

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-------- Original Message --------

On 7/31/24 02:06, sago35 wrote: @sago35 commented on this pull request. --------------------------------------------------------------- In [kbexpander.go](#44 (comment)): > + if !o.InvertDiode { + _ = expanderDevice.Pin(c).SetMode(mcp23017.Output) + _ = expanderDevice.Pin(c).Set(true) + } else { + _ = expanderDevice.Pin(c).SetMode(mcp23017.Input | mcp23017.Pullup) + } Is there a reason you are using Pullup here? I think the PR can be merged as it is now. Depending on the reason, it might be necessary to create a PR in the future that allows for selecting either Pullup or Pulldown, including for kbmatrix.go. I have one more request. Could you share the expected circuit diagram? kbmatrix.go assumes the following. I assume it's the same circuit, just differing in whether to use pullup or pulldown. [image.png (view on web)](https://github.com/user-attachments/assets/ea766aa2-07b2-40e1-9de4-56d535234798) https://kicanvas.org/?github=https%3A%2F%2Fgithub.com%2Fsago35%2Ftinygo-keyboard%2Ftree%2Fmain%2Fkicad%2Ffric10key%2Ffric10key — Reply to this email directly, [view it on GitHub](#44 (review)), or [unsubscribe](https://github.com/notifications/unsubscribe-auth/AMOCQA42CNROYQXOWYI6QFDZPATBDAVCNFSM6AAAAABLSZK6VSVHI2DSMVQWIX3LMV43YUDVNRWFEZLROVSXG5CSMV3GSZLXHMZDEMBYHEYTCNBZGE). You are receiving this because you were mentioned.Message ID: ***@***.***>

[sago35]

I see, it only supports pull-up. Understood.

https://ww1.microchip.com/downloads/en/DeviceDoc/20001952C.pdf

[sago35]

LGTM

Thanks for your contoribution!! @PercyJW-2