Support 4:3 aspect ratio with FRUIT_JAM_OS_4x3 environment variable

[relic-se]

The particular monitor I've been using with the Fruit Jam (an old Dell 1907FPt 4:3 monitor) doesn't support the default aspect ratio of Fruit Jam OS (720x400, 1.8:1).

I've introduced support for 4:3 aspect ratio (640x480) by adding an environment variable, FRUIT_JAM_OS_4x3, and some additional changes to positioning. I believe an environment variable is the best way to approach so that it is easier for users to maintain their device's settings between updates.

[RetiredWizard]

There was a PR merged into Circuitpython (adafruit/circuitpython#10534) which increased the number of displays that will work at 700x400. Have you tried running with the "absolute newest" firmware by any chance?

[relic-se]

I'm running 10.0.0-beta.2. This is a fairly old display that I'm working with, and I just don't think it's compatible.

Adafruit CircuitPython 10.0.0-beta.2 on 2025-07-30; Adafruit Fruit Jam with rp2350b

Not that it's entirely relevant, but this is the prompt I get when using the 1.8:1 aspect ratio:

[FoamyGuy]

I think it's great to support 640x480 better with the layout, but we can do it using the existing display environment config vars instead of introducing a new one for the OS.

[RetiredWizard]

I'm running 10.0.0-beta.2. This is a fairly old display that I'm working with, and I just don't think it's compatible.

For what it's worth Google AI seems to think 720x400 will work on your monitor, but who knows 🤷. I did have the same problem on the monitor I was using, the "Absolute Newest" version from this page https://circuitpython.org/board/adafruit_fruit_jam/ got it working

[relic-se]

For what it's worth Google AI seems to think 720x400 will work on your monitor, but who knows 🤷. I did have the same problem on the monitor I was using the the "Absolute Newest" version from this page https://circuitpython.org/board/adafruit_fruit_jam/ got it working

I don't think I'd trust Google AI on that one 😆.

I have an MSI MAG401QR ultrawide monitor that works well, but I think there's some appeal to getting the Fruit Jam working with older monitors. Although there's likely a better work around, I can imagine someone running it into composite/VGA adapter to output to an old CRT. While the widescreen aspect ratio would likely work, a standard aspect ratio might look clearer and less squashed on the x axis.

[RetiredWizard]

(an old Dell 1907FPt 4:3 monitor)

It turns out I actually have a Dell 1908FP 4:3 monitor and when I run 10.0.0-beta 2 I get exactly the screen you've posted, however with the "Absolute Newest" firmware, Fruit Jam OS runs fine.

I'm not suggesting that this PR isn't helpful, just that you may have more options than you think.

[relic-se]

It turns out I actually have a Dell 1908FP 4:3 monitor and when I run 10.0.0-beta 2 I get exactly the screen you've posted, however with the "Absolute Newest" firmware, Fruit Jam OS runs fine.

Oh wow, I didn't realize how recent that update was. I'll give it a try! I'm sure I'll find this out for myself soon, but how does it handle the aspect ratio? Does it stretch the image or does it add black borders to the top and bottom?

I'm not suggesting that this PR isn't helpful, just that you may have more options than you think.

Being the starting point for most users of the Fruit Jam, I think it's important to make it versatile. Thank you for your review/comments!

[RetiredWizard]

but how does it handle the aspect ratio?

It adds the Black boarders (letter box) at the top and bottom.

[RetiredWizard]

For some reason, entering Breakout and then pressing ctrl-c to exit results in the following error:

Traceback (most recent call last):
  File "/apps/Metro_RP2350_Breakout/code.py", line 530, in <module>
KeyboardInterrupt: 

Code done running.
soft reboot

Auto-reload is off.
code.py output:
Traceback (most recent call last):
  File "code.py", line 76, in <module>
AttributeError: 'NoneType' object has no attribute 'width'

supervisor.runtime.display is apparently returning "None" after the reload.

[RetiredWizard]

I've tested on an old DELL monitor using both 10.0.0-beta 2 and 10.0.0-beta.2-3-gf86bf4c085 (absolute newest) at both 640x480 and 720x400. As expected 720x400 doesn't work with 10.0.0-beta.2 but the PR looks good to me.

[relic-se]

I've tested on an old DELL monitor using both 10.0.0-beta 2 and 10.0.0-beta.2-3-gf86bf4c085 (absolute newest) at both 640x480 and 720x400. As expected 720x400 doesn't work with 10.0.0-beta.2 but the PR looks good to me.

I did switch over to absolute newest and got the same result. Even still, I prefer to run it in 640x480 because it removes the borders and I think it scales better (don't quote me on this).

I've also tested the lower resolutions. They all still work with the UI and this particular monitor. The only remaining issue is that the help text is doubled in size and draws over the first item, but I don't think there's anything we can do about that without introducing a special half size font (not worth it, imo).

[FoamyGuy]

Thank you! This is a great improvement over the prior hardcoded display behavior.

I tested all 4 displays sizes 720x400, 640x480, 360x200, and 320x240 and all run properly now.

As noted in other comments the smallest sizes 360x200, and 320x240 do result in the upper left help text overlapping on top of the first icon. I'll probably tinker further with the layout and see if we can fit that help text in a single row along the bottom.

[tannewt]

The particular monitor I've been using with the Fruit Jam (an old Dell 1907FPt 4:3 monitor) doesn't support the default aspect ratio of Fruit Jam OS (720x400, 1.8:1).

720x400 isn't really the default. It is only used if the monitor reports supporting it.

Could you run this test code to show what the monitor reports supporting? https://learn.adafruit.com/using-dvi-video-in-circuitpython/monitor-display-capabilities

[relic-se]

Could you run this test code to show what the monitor reports supporting? https://learn.adafruit.com/using-dvi-video-in-circuitpython/monitor-display-capabilities

The absolute newest version of the core fixes the problem on this monitor. I'm not sure of the exact PR to reference. Here's the output of that program if you're still interested:

I2C Present
Device 0x50 found!
Valid EDID signature!
Good EDID checksum!

Supported Display Modes (11 found):
==================================================
  720x400 @70Hz
  640x480 @60Hz
  640x480 @75Hz
  800x600 @60Hz
  800x600 @75Hz
  1024x768 @60Hz
  1024x768 @75Hz
  1280x1024 @75Hz
  1152x864 @75Hz, Aspect: 4:3
  1280x1024 @60Hz, Aspect: 5:4
  1280x1024 @60Hz

Default resolution: 640x480
Preferred resolution: 1280x1024