Reviving the TI-92 calculator into a RPI PC

After a pause, I'm back on the project. I was waiting for a good color display. WaveShare has released a cool 800x480 IPS color touch display (4 inch). This one seems to fit well into the re-visited pc board.  

Tonight we are going to test the freshly received display with our selected Raspberry PI ZERO 2W . If ok, we will adapt the board and send to production

Hackster.io has published a detailed article about this mod.

https://www.hackster.io/news/in-search-of-the-perfect-portable-pocket-terminal-sometimes-there-s-no-school-like-the-old-school-a20ef49d2082

Preparing to add a very low power switch... 

I found the source to use the XTP2046 chip with the RPI PI ZERO

The Datasheet is here 

I had to revert KICAD back from nightly build to stable and lost a pqart of the work because of file down compatibility issues. I had to redo the routing.

Here is the first experimental schematic diagram (still some work to do).  Until I get a Compute module 3, I will use the RPI PI ZERO W computer.

Next step tomorow

I also got the Voyage 200 model which replaced the TI92. All the work made with TI92 will speed up the conversion process  for the new model

Now trying to connect the 4 inch to the RPI PI ZERO . Looks like this tutorial will ease the process . Shows how to install ST7796s on raspbian. The website also offers pre-compiled images.

I tried to route a bit... everything seems ok. There is much room to work with security and comfort.

Before I finish the routing I have to finish the schematic with the RPI stuff.

Time to read on how to drive the display with the RPI ZERO and RPI CM4 .

oups, thanks to you for the comment

There was a mistake in the buttons footprints

I corrected the button mistake ... and updated the files

I've just updated the GITHUB directory with the latest kicad dev (please is the last nighly built of kicad to open the files)

I added the buttons on the board.

It is not time to work on the raspberry pi zero and  RPI Compute module 4 add.