OLED mod

[Kingstener]

[ADMIN NOTE] :
These instructions are now obsolete ! OLED screens are now directly supported by the HxC Firmware.
No need to any additional chip. Have a look to this page for the right instructions :
https://hxc2001.com/docs/gotek-floppy-e ... -oled.html



Hello,
I would like to show my small OLED modding, maybe it helps someone...
The LCDs were all too big for my uses, so I take a 0.91 inch OLED display to build that in the GOTEK.
A small Attiny85 that translates the I2C code from the LCD works to control the OLED display.
The diy project can be found over my homepage (unfortunately only in German)
PCB design suggestions and flashfiles are included as an attachment in the document - so it contains all you need
- sorry for my english, it's google translation only-

[Paradoxic]

Nice Job !!

[teevee]

Hi Kingstener,

Thank you for the creative input, this is exactly what the community needs!

Would it be possible to make a English version of this Oled mod pdf, maybe with the concept of "cutting to the chase" or "Keep it simple" in steps with same pictures?

I´m sure lot of the users here would appreciate such effort

[Kingstener]

Sorry, but i can only translate by the google translator, so it should rather do someone who masters the languages otherwise this becomes completely unintelligible - like a chinese manual

[teevee]

Sorry, but i can only translate by the google translator, so it should rather do someone who masters the languages otherwise this becomes completely unintelligible - like a chinese manual

If you can make a very simplified version, then I would gladly help you out

[Paradoxic]

Here's my (almost complete) effort at translating the text. I haven't created a complete document with photos.......
I couldn't find any links to the Attiny85 code or flashing instructions btw....

The GOTEK floppy emulator has become a very useful tool for me. However its original LED digit display limits its usability, as floppy disk images can only be numbered. Now there is provision to connect a 2 x 16 characters LCD to display folder and file names. However, due to its size, it is only possible to mount it externally, which is not exactly optimal. A solution is to use a 0.91 inch 128 x 32 graphic OLED display, which will fit into the case with a little handiwork. Now the emulator can display meaningful names.

The components (pictured):
The 0.91" 128x32 I2C OLED Display (photo of display)
Four jumpers (from the LED display) (photo of jumper wires)
And the interface board with the Attiny85 (photo of interface board)
Schematic and layout drawings of the interface board (drawings)

The HxC firmware from J-F Del Nero implements control for a TM1651 (I2C-bus 4x7Segment led display driver) and a PCF8574 (I2C-bus 8-bit I/O Port Expander) for the 2 x 16 character LCD. The circuit above translates the data which would be sent to the LCD display to that required for the SSD1306 with 128 x 32 pixel OLED display. The board is plugged on the J7 of the GOTEK and connected to the display via jumpers. The display also responds to the HXC "Backlight" control.

A third button, of identical design to the 2 on the GOTEK was fixed to the front of the GOTEK, the button protruding through a 3.8 mm hole drilled at a distance of 7.5 mm to the right of the existing buttons, and connected to the JA jumper on the GOTEK pcb. (HxC firmware release notes.... "This additional button and the I2C LCD screen allow you to freely select a file image without the indexed mode or any selector software.")
Inside the GOTEK case, the two LED display spacing bars have to be cut sufficiently to allow the OLED display to sit flush. Also the outside of the holding tab on the lid needs to be trimmed to clear the jumper wires.

Cut the distance bars to allow the display to sit flush (photo of front of case from the inside)
And also trim the tab on the cover (photo of the case cover)
Interior view (photo of modified GOTEK)

As an alternative, it is possible to use a 0. 91inch SPI OLED display. This has the advantage that the LED display spacer bars do not need to removed, since it fits in between. However it has the disadvantage of being about 1.5 mm taller. When mounted with the display completely showing in the window of the GOTEK, its connectors facing upwards means the lid can't be fitted, and the 'drive' could be used only in closed systems. For completeness sake it has to be mentioned here for anyone who wants to modify the case and accept the 'open' case.

Fits in the width between the spacer bars (photo of SPI OLED board mounted in case)
Here are the circuit and layout drawings for the SPI version, where the reset of the OLED is implemented with an RC-element...... um keinen größeren AVR verwenden zu müssen.

There is however a way to get the cover onto the case:
The connector on the display board is de-soldered, the board top edge trimmed down to the soldered connection points, and the connection to the interface board now made using a piece of flat cable. Slightly more effort, but worth it.

The completely wired assembly (photo of modified GOTEK)
Solder pins removed (photo of original display board)
And board shortened (photo of shortened board)

The description does not claim to be complete and professionally correct, use the information provided here at your own risk! (disclaimer)

[Kingstener]

Thank you both for the support, I have tried to create a step-by-step guide in English - under the above link.
If this is understandable and corrected I can perhaps upload it here?

Attachments to PDF documents can be accessed via view / navigation panels / attachments (adobe reader)

[Paradoxic]

Thank you both for the support, I have tried to create a step-by-step guide in English - under the above link.
If this is understandable and corrected I can perhaps upload it here?

Attachments to PDF documents can be accessed via view / navigation panels / attachments (adobe reader)

Good work Kingstener. That is easy enough to follow

[teevee]

Thank you both for the support, I have tried to create a step-by-step guide in English - under the above link.
If this is understandable and corrected I can perhaps upload it here?

Attachments to PDF documents can be accessed via view / navigation panels / attachments (adobe reader)

Good work Kingstener. That is easy enough to follow

+ 1

[Kingstener]

OK, thanks
Directly can be uploaded here only pictures, so the way remains over the link in first post.
wish much success...

[cbrunschen]

OK, thanks
Directly can be uploaded here only pictures, so the way remains over the link in first post.
wish much success...

That mod looks great!

Would you be willing to make the source code available for the ATTiny that controls the display? that would make it possible for others to contribute changes / improvements, or perhaps port to other microcontrollers.

Best wishes,

// Christian

[Kyran]

With the Ardinuo IDE I'm able to upload standard sketches to the Digispark Attiny85 via USB. However, I haven't figured out how to do the same with the HEX file. Do I treat the HEX as a bootloader?

[Kingstener]

@cbrunschen
I rather think not...
What are the complaints that make it necessary to improve?

@Kyran
Of course you can upload a hex file with the command line of the bootloader "mikronukleus *.hex".

But I think this device is here rather unsuitable ...
- the pullup resistors on the GOTEK side I2C are missing
- the bootloader must be configured with the option "Define Bootloader entry condition to ENTRY_JUMPER", other while means it booting with waiting (5 seconds timeout) and the HxC does not recognize any display
Or the Hexfile is flashed directly over a programmer without a boot loader, then it could work
But then you can put the few parts right on a veroboard

[AW99]

Nice display. Only bad thing is, that the user must always put the head down to see the display on the side. Would also be not a bad idea to make it on the upper side of the Gotek. I mean, when the Gotek is used in his own case and is not mounted in another case.

[Kingstener]

You will not believe it, but there are really very much devices that have a floppy drive on the front and it is specifically made for this, to ease the handling ... not for a gaming console :/