TasmARI - Atari als IoT-Familienmitglied

[pancio]

Hallo zusammen!

In diesem Thread: https://abbuc.de/forum/viewtopic.php?p=36044#p36044

habe ich eine Beschreibung und den Status des Projekts zum Zeitpunkt der Einreichung beim Abbuc HW 20025-Wettbewerb vorgestellt. Hier möchte ich euch über den Fortschritt und die Herausforderungen bei der Entwicklung der Benutzeroberfläche informieren. Da der Wettbewerb noch nicht abgeschlossen ist, kann ich nicht alle technischen Details verraten, denke aber, dass ich die Entwicklungsphasen und Möglichkeiten zur Fehlerbehebung aufzeigen kann. Ich werde auch versuchen, die im Gerät verwendeten Komponenten zu erläutern, damit sie später in anderen Projekten verwendet werden können.

Dieser Text wurde automatisch aus dem Englischen übersetzt – bitte verzeiht mir also etwaige Unklarheiten oder Rechtschreibfehler.

Mehr über TasmARI könnt ihr im oben verlinkten Beitrag lesen. Kurz gesagt: TassmARI ist ein einfaches Gerät, das über den SIO-Anschluss mit einem Atari verbunden wird und über WLAN mit IoT-Geräten über das MQTT-Protokoll kommunizieren kann. Dadurch kann der Atari als Controller für unser digitales Zuhause genutzt werden. Das Herzstück der TasmARI-Schnittstelle ist ein Modul, das auf dem ESP32-Mikrocomputer läuft – einem sehr beliebten Mikrocomputer mit umfangreichen Anwendungen in den meisten IoT-Geräten. Ich habe mich für ESP32 entschieden, weil mehrere sehr fortschrittliche Betriebssysteme für diesen Mikrocomputer entwickelt wurden, darunter Tasmota. Aus der Kombination der Wörter Tasmota und Atari entstand TasmARI. :-)

Blockschaltbild

TasmARI Block Diagram

TasmARI_block.png (12.26 MiB) 1161 mal betrachtet

Wie im Blockdiagramm dargestellt, verfügt unsere Schnittstelle über ein OLED-Display, eine LED-Anzeige (acht LEDs für den PCF8574-Controller und zwei für die SIO-Übertragungsanzeige) und vier Tasten auf der OLED-Anzeigeplatine. Der Zugriff auf Display und Tasten erfolgt über den I2C-Bus. Die Platine enthält außerdem mehrere Puffer, die als Pegelwandler dienen, um die Spannung der Atari-Signale an die ESP32-Eingänge anzupassen.

PCB-Visualisierung erstellt in KiCAD:

Visualization FRONT

Tasmari_1.0RC1-front.png (159.08 KiB) 1161 mal betrachtet

Visualization BACK

TasmARIv1.0RC1-back.png (103.27 KiB) 1161 mal betrachtet

Und die fertige Prototypplatine, gestern geliefert und schnell zusammengebaut:

PCB 1.0R1

signal-2025-08-07-153855_004.jpeg (874.79 KiB) 1161 mal betrachtet

PCB 1.0R1 - equipped

signal-2025-08-07-153855_002.jpeg (873.51 KiB) 1161 mal betrachtet

Erster Test (ohne Atari)

First Display Test

signal-2025-08-07-153855_005.jpeg (988.71 KiB) 1161 mal betrachtet

Ich plane, dieses Wochenende mit den Tests zu beginnen!

Br,
pancio

[pancio]

Hi,

The silent hero of the episode are: strapping pins :-)

I didn't manage to accomplish much with the project, but I'd like to share a few conclusions and discuss a few problems I encountered during implementation. The first Tasmari RC1 board was a bit disappointing because I didn't anticipate that the ESP32 had several strapping pins, the state of which affects how the ESP32 boots. I supposedly knew this beforehand, but somehow I overlooked one of them, and my Tasmari wouldn't boot correctly. Of course, I managed to get the board working (I had to cut and rewire a few traces), but I still had to redesign the circuit. That's how the RC2 version was born...

TasmARI RC2 - visualisation

Tasmari_RC2-board.png (189.42 KiB) 796 mal betrachtet

The board arrived a week later, and I assembled two of them at once. I was very surprised that the new version wouldn't start again... It turned out that while swapping several GPIOs, one of the strapping pins was being forced into an incorrect state by the Atari's PROCEED signal. The solution was to cut the trace and remove the signal... The module booted.

TasmARI RC2 board

TasmARI-RC2-board.jpeg (1.29 MiB) 796 mal betrachtet

So, success! But not entirely :-)

The principle I adopted for communication between Atari and Tasmota OS is very simple: a simple program in Berry listens on the serial port and everything that comes in is interpreted as a command for Tasmota.
This time, the Tasmota operating system surprised me... it turns out that in serial-bridge mode, which is used for communication between the Atari and Tasmota OS, it intercepts and attempts to execute everything that appears on the console, while I assumed these would only be messages coming from the Atari. Interestingly, when I use the ESP32 module without the Tasmota PCB, the problem doesn't occur! I again began to suspect strapping pins.

TasmARI-console-errors.png (285.17 KiB) 796 mal betrachtet

It also turns out that the problem disappears after 10 minutes and the Atari can take over communication with Tasmota OS! That's a clue – I already know that logging from the serial port can be disabled via the SerialLog option, but it's not very pretty... I'll have to look into this a bit more.

After reading a few pages of the ESP32 documentation, I rebuilt the wiring diagram, added some pull-up resistors, designed the RC3 version, and am waiting for the boards – they should arrive this week. We'll keep fighting :-)

Oh! I forgot to mention what other difficulties I encountered... anyone who has ever tried to insert a Sikor SIO socket will understand! THESE ARE NOT SOCKETS FOR NORMAL PEOPLE! :-) It's so difficult to insert into standard PCB holes that after the entire operation, I had cut my hands and damaged two SIO sockets (and they're not cheap!). So, I decided to add a standard pinheader to the RC3 version to make it easier to check the SIO pins and also to save on the expensive Sikor SIO sockets...

TasmARI RC3 - visualisation

Tasmari-RC3-visualisation.png (207.96 KiB) 794 mal betrachtet

Will be in touch!
pancio

[pancio]

Hi,

Unexpectedly, the last few weeks have been very difficult for me, both at home and at work. I regret not having had time to share everything I wanted to about the project – I hope to make up for it in the future.

Just a quick update today regarding the change in the execution module. I decided to use the ESP32-S3, which has more features – especially more GPIO pins, which aren't specifically assigned to specific functions like the basic ESP32. The ESP32-S2 allows for greater operational freedom and easier development. Unfortunately, there's also a downside: the ability to play Atari sounds via the SIO_AUDIO input is gone (the ESP32-S2 doesn't have DACs). I'm not worried about this, though, because I can always add an external DAC via the I2S bus – which I'll do if the prototype works :-)

The current PCB is designed to support three different displays (two with buttons) – this will allow for greater flexibility in your own designs. I also dropped the LED bar indicators. Instead, I added a separate power supply :-)

BR,
pancio

[wosch]

Just a quick update today regarding the change in the execution module. I decided to use the ESP32-S3, which has more features – especially more GPIO pins, which aren't specifically assigned to specific functions like the basic ESP32. The ESP32-S2 allows for greater operational freedom and easier development. Unfortunately, there's also a downside: the ability to play Atari sounds via the SIO_AUDIO input is gone (the ESP32-S2 doesn't have DACs).

hm
Welcher wird jetzt verwendet? S2 oder S3

Which one is being used now? S2 or S3?

Greetings
Wolfgang

[andymanone]

War wohl ein Typo.

Der S2 hat zwei DAC´s und der S3 nicht mehr.

Gtx.,
andY

[pancio]

It's typo - should be S3. I'm using this module (clone): https://docs.espressif.com/projects/esp ... -reference

S2 has only one single core.

EDIT: https://openelab.io/blogs/learn/ultimat ... d-esp32-s3

BR,
pancio