Designing a premium 24” wall-mounted touchscreen for Home Assistant - Dell P2424HT vs iiyama T2452MSC (Raspberry Pi, DDC/CI, long-term experience)

Hardware
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Hi everyone,

I’m currently designing what I hope will become the main wall-mounted control panel for my home.

This isn’t intended to be “just another dashboard on the wall”. I’m trying to build something closer to a premium integrated home display that also happens to be a Home Assistant control panel.

The project is still in the design phase, so I’m not asking “which monitor is best?”. I already have a decision framework and I’m trying to eliminate unknown risks before buying a test unit.

Current architecture:

• Home Assistant runs on my NAS.
• Raspberry Pi 5 (Ethernet) only acts as the kiosk client.
• Chromium in kiosk mode.
• Immich provides family photos.
• I’m planning to build a lightweight custom “Home Display” web app (photos, clock, weather, solar production, battery, alarm, etc.).
• The full Home Assistant dashboard only appears when someone interacts with the display.

The panel will operate in four states:

A. Screen in standby.
B. Presence detected → wake monitor → Home Display.
C. User touches the screen → Home Assistant dashboard.
D. No presence for a while → return to Home Display → back to standby.

After several weeks of research I’ve narrowed the monitor choice down to:

• Dell P2424HT
• iiyama T2452MSC-B2AG (or T2438MSC-B2 if you have direct experience)

I’m specifically looking for hands-on experience with these exact monitors (or extremely close models), ideally with Raspberry Pi OS or Linux.

The things I’m trying to validate are:

• Does DDC/CI work reliably?
• Can brightness be controlled with ddcutil?
• Can the monitor reliably enter and exit standby?
• Does the USB touchscreen recover correctly after standby?
• Any firmware quirks?
• Any long-term reliability issues after months or years?
• Image quality for displaying photos most of the day.
• Anti-glare performance in a bright hallway.
• Did you have to do anything non-obvious to make DDC/CI or DPMS work correctly?

I’m not looking for generic recommendations or “I’d buy a tablet instead”. I’m specifically interested in eliminating unknown risks before purchasing the first test unit.

Finally, if you’ve built a similar permanent wall panel, what would you do differently today?

I’m especially interested in the mistakes you only discovered after living with it for months or years.

Thanks!

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I’m also very interested in exactly the same requirements. Have you already found or tested a solution?

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I’ve been running a wall-mounted display in my kitchen for many years — not the exact hardware you’re evaluating, but some of my experience with standby/DDC behavior may still be useful.

I started with a Samsung display as an experiment to see if my family would actually use it. It’s not a touchscreen, just a plain monitor plugged into a Raspberry Pi 4. I later swapped in a Dell monitor (different model than the P2424HT you’re considering) when the Samsung’s power supply died from heat.

On your specific questions, based on my Dell + Pi 4 setup running TouchKIO:

  • DDC/CI reliability: Since moving to TouchKIO, I can turn the screen on and off reliably.
  • Brightness via ddcutil: Haven’t tried it.
  • Standby enter/exit: Yes, reliably. I believe the TouchKIO script turns off the HDMI interface rather than using true monitor standby.
  • Touch recovery after standby: No touch on my unit, so I can’t speak to this.
  • Firmware quirks: None that I’ve noticed.
  • Long-term reliability: My original Samsung developed heat problems, but that was from running it on constantly inside an enclosed 1x4 box with little ventilation — not a monitor defect.
  • Image quality for photos: No issues.
  • Anti-glare in a bright hallway: Direct sun at the wrong angle does wash it out somewhat when I’m sitting at a bad angle, but I don’t think there’s a real fix for that regardless of panel.
  • Non-obvious setup steps for DDC/CI or DPMS: Just followed TouchKIO’s setup docs (GitHub - leukipp/touchkio: Home Assistant Touch Panel Kiosk application for a Linux device (e.g. Raspberry Pi) with Touch Display. · GitHub) and it worked. I recall having to adjust HDMI power settings in the boot params.

One lesson from living with this setup for years: heat and enclosure airflow matter more than I expected — my first power supply failure was from running the display 24/7 in a sealed box. I’m now looking at a Waveshare display for my next revision since it mounts the Pi and draws power directly from the monitor, solving the clearance/heat issue I ran into with the Dell in my old 1x4 enclosure.

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Hi, I’m using this to control the display from a few RPi’s

"echo 0 | sudo tee /sys/class/backlight/rpi_backlight/bl_power"

Even though using dark dashboards, on a wall tablet in the kitchen white was the better choice.