Projekt Texas Instruments Ti92


#1

Hello everyone my name is Markus (Max)

I’m from Austria.
Dear Mick i love your Videos and you are the real man about electronics.

Sorry for my bad English but the school is long time ago😅

Well i start a projekt to implement raspberry pi or similar sbc’s to fit in the old school texas instruments calculator ti92.

The goal is that you have a full portable “hacking” machine for debugging and learning.
I use a customized 4"lcd with touch, with a resolution of 800x480.
its produced for raspi’s and fits perfect in the ti92 case.
The touch is now over spi but i desolder the header an drive it with an usb touchcontroller so its no problems with the headersize or driver’s.

the original pcb inside the ti92 is one pice and not jusefull.
so i’m design my own pcb with easy eda but i am a newbi in easy eda😕

so the next step is a pcb with keyboard matrix with a teensy 3.2 so you can customize your own keyboard layout.
a raspberry pi header
a usb 2.0 hub
a lipo charging circuit
a pi header
and maybe the driver circuit for the lcd and a trackball
so really much stuff and work

so things i have been done
lcd customized… check
test space in the case… check
lipo charging… check
its a finished circuit from an 10mAh powerbank
that is small and can deliver 5V output at the same time it will be charging the lipo
so now i am design the pcb an there are the
problems:

rubber button pads in easyEDA.
lcd driver curcuid from lcd is no open hardware.
connectors for hdmi and usb but i think i juse the small hdmi kable from china

and the biggest problem is the design of the pcb
because there is so much to take care on the pcb
so i’m not sure if i can doing it, but i think with the help from the community i will go step by step
to finish this project. :slightly_smiling_face:

pictures are comming soon and i am open for any idea’s

so thanks for reading and maybe your help
:grinning:


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well this is my basic pcb

i know its not good but i spend only 1h for drawing.
i need to learn more about easyeda🙄

are the rubberpads are correct?
there is no soldermask on it.
i got it from the libraries.

maybe someone here has more know how about
rubberbuttons🙂

so this weekend i test the hardware setup
with an upcore board.
yesterday i testet a upboard and the current draws less than 1.6A when i install win10pro.
so thats really good because my powerbank
can deliver 2.7A and 1A at 5V… yeah


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#10

Hello again

so i orderd 10 PCB from JLCPCB with a view rubberbutton layouts.

Also on the PCB are little Breakoutboards for an Atmel ATTINY 461.

I get a lot of this chips from my work so i can juse them in small projekts in the future.

So these are my first PCB and i hope the are not so bad because its the first time for me using EasyEDA.

I post pictures when i get the PCB’s