Replacement Keyboard Project Update

Discuss the CreatiVision hardware: models, revisions, fixing, hacking and modding.
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Scouter3d
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Re: Replacement Keyboard Project Update

Post by Scouter3d » Mon Apr 05, 2021 12:42 pm

Hi,

Done a bit of testing:
With 1x CD4066 (4 switches) hooked up to the Arduino UNO and to Pins 1,2,3,4 and 10 of the left CV controller i was able send Keypresses :0)
with only the 4 switches the CV recognizes the characters "2,3,6,SHIFT,",#,&" :0) see image of endless keystroke loop with errors in CV Basic every time the line gets too long ;0) and reflexion of my window :0)
4066_loop.jpg
using DC4066s instead of the MT8808 may become my preferred way... as they are readily available, very cheap and the arduino code may be faster and smaller...

Even so, here is how i will try to connect the MT8808 (when it arrives from china in a few weeks :0()

WARNING: WITH THIS HOOKUP OF THE MT8808 YOU CAN DAMAGE THE CREATIVISION!
MT8808_hookup_small.jpg
Cheers, TOM:0)
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Last edited by Scouter3d on Mon Apr 12, 2021 5:28 am, edited 1 time in total.
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cheshirenoir
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Re: Replacement Keyboard Project Update

Post by cheshirenoir » Tue Apr 06, 2021 9:47 am

Aaah clever! I didn't spot that we only had to parse the 4 lines if we bridged the left and right pins.

I'll redo it in KiCAD tonight. Maybe I'll even add the Arduino :-D
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Scouter3d
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Re: Replacement Keyboard Project Update

Post by Scouter3d » Tue Apr 06, 2021 11:34 am

Hi Chesh,

the left and right pins are allready internaly bridged! (in fact they are the same 8 lines, they are only present on both handsets because they are physically seperated)

Cheers, TOM:0)
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Scouter3d
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Re: Replacement Keyboard Project Update

Post by Scouter3d » Mon Apr 12, 2021 5:26 am

Hi, a quick warning! the solution with one MT8808 is possibly harmful to the CV! (i burned two PIA chips inside the CV...) so please do not try this at home :0)
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Mobsie
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Re: Replacement Keyboard Project Update

Post by Mobsie » Tue Apr 13, 2021 9:35 am

Oh no, hopefully easy to fix for you
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Scouter3d
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Re: Replacement Keyboard Project Update

Post by Scouter3d » Tue Apr 13, 2021 12:33 pm

Mobsie wrote:
Tue Apr 13, 2021 9:35 am
Oh no, hopefully easy to fix for you
Hi Mobsie, now i have a socket in my CV for easy replacement of the PIA :0) (luckily i had 3 spare PIAs)
Greetings, TOM:0)
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