Software Add-On for the MiSTer FPGA showing Text or Pictures based on the loaded core on a (OLED) Display driven by an Arduino which is connected via USB to the MiSTer.
NEW!
SD Version with live download of Pictures from SD Card (see below for more details).
IMPORTANT!
Both Arduino Versions (SD and Standard) uses now (2021-02-07) the Serial Speed of 57600 baud.
You need to change/replace the tty2oled file on the MiSTer as well to support this.
Updates
See https://github.com/venice1200/MiSTer_tty2oled/blob/main/Updates.md
At first I had the idea to add an Display which shows only the MiSTer Logo.
After a bit of searching I found the possibilty to get information about the actual loaded Core out of the file /tmp/CORENAME.
I tried tail -F /tmp/CORENAME which results in error messages so I choose cat /tmp/CORENAME in a timed loop.
Later the timed loop was replaced by an inotifywait -e modify "/tmp/CORENAME" which makes the system more reactive.
I tested an USB (-Serial) connection between an Arduino
and the MiSTer (not MiSTer's User Port (Serial IO))
as this is an standard communication feature on Arduino's and easy to use.
And USB Ports are available for most of the MiSTer users is some way.
My ATMega 1284 with an FTDI Serial Adapter was sucessfully detected as /dev/ttyUSB0 by the MiSTer.
Later I used an ESP32 with an CP21xx Chip because of storage and speed.
My actual Display is an 3.12" SSD1322-OLED with 256x64 Pixel connected via SPI to the ESP32 MCU.
Arduino
For the Arduino Code you need to add this Library https://github.com/olikraus/u8g2 to your Arduino System.
This Library needs the pictures in XBM Format. I use Krita for converting.
Just open your B/W Picture file and save it as XBM. See the Arduino Code logo.h file for details.
The included XBM Pictures are converted to an max Size of 256x64 Pixel.
The Arduino Code can be easily adapted to other Displays, Display-Libraries or Arduino's.
There is a lot of commented code in the files. I will clean it up step by step.
MiSTer
On the MiSTer you need two scripts.
The first script /etc/init.d/S60tty2oled is an starter script for the second script /usr/bin/tty2oled
which handles the communication to the Arduino via the USB-Serial tty device.
Video Part 1: https://imgur.com/a/JOnaKPq
Video Part 2: https://imgur.com/gallery/Ek9oFN1
When the MiSTer boots up the script /etc/init.d/S60tty2oled is called.
This script does nothing more than calling the script /usr/bin/tty2oled and sent it to the background,
but only if /usr/bin/tty2oled is found and is executable.
The script /usr/bin/tty2oled checks at first the system for the device /dev/ttyUSB0.
If the device is not found the scripts ends here.
If the device is found the tty-device parameter are set with the stty command.
Now the script sends an First Transmission.
First Transmission?
During my tests I got sometimes weird display startup behavior when the MiSTer's was powerred on.
Sometimes the text MENU was written instead of the MiSTer Picture shown.
Maybe some sleeping bits in the serial channel 😏.
After I added the First Transmission to the script the problem was gone 😄.
Now the main loop is started and checks the existence of the file /tmp/CORENAME.
If the file doesn't exist the script tries again and again and ...
If the file exists, the file's content is read using cat /tmp/CORENAME,
stored into the variable newcore and send to the tty Device.
At the end of the main loop the script waits for the next change and re-starts the loop.
Every loop the Corename is checked but the data are sent only if the Corename has changed.
The Arduino receives the transferred Corename.
If the Corename is within a list of known Names the corresponding picture is shown.
If the Corename is unknown just the Corename is shown.
The used font for the Text can be changed within the Arduino Code.
See the list of fonts for all in the Library included fonts.
To prevent Display flickering the Text or Picture is only updated if the received Corename has changed.
Known Corenames (non SD Version)
The following Corenames are (currently) identified and an dedicated or generic Picture is shown.
Arcade: llander, mooncrgx ,mpatrol
Computers: AO486, APPLE-I, Apple-II, AtariST, C64, Minimig, PET2001, VIC20
Console: ATARI2600, Genesis, NEOGEO, NES, SMS, SNES, TGFX16
Other: MEMTEST, MENU (shows the MiSTer Logo fading in with an particle effect), QWERTZ (does nothing, it's first transmission).
The SD Version supports the live download of Pictures from SD Card. No need to keep the Pictures in Code.
You need an Arduino compatible Hardware plus/with an SD Slot/Breakout.
I use an ESP32 TTGO-T8 v1.7.1 with an integrated SD Slot.
The SD Card must be formatted with FAT or FAT32.
If the SD Card was found an SD-Card Icon is shown on the Startup Screen.
The Arduino Sketch searches for the XBM converted pictures in the root folder of the SD Card.
The Pictures must have the size of 256x64 Pixel for the used SSD1322 Display.
The filename must be the name of the core with .xbm as extension.
Example: The Arcade Lunar Lander has the corename llander means the filename needs to be llander.xbm.
See https://github.com/venice1200/MiSTer_tty2oled/tree/main/Pictures/xbm_sd for examples.
The Arduino receives the transferred Corename and checks the SD Card for an corresponding file.
If the file is found it's loaded and shown on the Display.
If the file or the SD card is not found just the Corename is shown as Text.
With the SD Card it's easy to add or update the Pictures by adding or changing the files on the SD Card.
Technical Note:
The SD Version uses an dedicated SPI Interface because of issues using an OLED and an SD Card together on one ESP32 SPI Interface.
Core with Picture
Core shown by name
You can easily test your Display by sending text from the Arduino's Serial console
set to 9600 57600 baud with LineFeed \n activated.
The following Text-Commands have special functions:
| Text | Function |
|---|---|
| cls | Clear Display |
| sorg | Show Display's Power-On Text |
| bye | Show Sorgelig's Icon 😄 |
| MENU | Show MiSTer Logo with randomly picked Effect |
| MENU0..MENU11 | Show the MiSTer Logo with some Effect |
| File/Folder | Description |
|---|---|
| S60tty2oled | Starter Script, must be placed on MiSTer in folder /etc/init.d/ |
| tty2oled | Communication Script, must be placed on MiSTer in folder /usr/bin/ |
| MiSTer_SSD1322 | The Arduino Project containing the .ino and .h file(s) |
| MiSTer_SSD1322_SD | The Arduino Project with SD Support containing the .ino and .h file(s) |
| Pictures | Just Pictures 😄 |
| Pictures/BMP | Logos/Pictures in BMP Format |
| Pictures/XBM_SD | XBM Logos/Pictures for the SD Version |
Use an second serial port to free up the MCU's programmer port.
Use an ESP32 with an SD Micro Slot for the Pictures DONE.
MiSTer on Github: https://github.com/MiSTer-devel
MiSTer Forum: https://misterfpga.org
Add-On Thread : https://misterfpga.org/viewtopic.php?f=9&t=1887
...work in progress