Experimental: LilyGO T5 E-Paper S3 Pro, test build 2 on Cairn 127. Sharp text at the panel's full resolution. Please send a photo and a log.
What experimental builds are. Use MeshCore-T5EpaperPro-Cairn127-2026-11-03-full.bin.
Cairn 127 for the LilyGO T5 E-Paper S3 Pro (H752-01) -- test build 2 (2026-11-03)
New in this build:
- Text at the panel's own resolution. The interface now draws at 960x540, one pixel on the glass for
each pixel drawn, instead of 480x270 blown up into 2x2 blocks. Letters keep their real shapes and
stay open; small text uses a slightly heavier weight. This was the big complaint about test 1.
- If the panel's power chip was left latched by a crash (the screen stuck on an old page with no way to
reset), the T5 now clears it as it starts.
- USB drive mode (Settings > Hardware > Storage > USB drive): the microSD card as a disk on a computer.
- The live page (Settings > Wi-Fi > Live page): the radio, packets and nodes heard, in a browser on the
same Wi-Fi.
- Everything else in Cairn 127, such as blocking a node (long-press it in Nodes).
It replaces the firmware you have now. Nothing in it can damage the board, and you can always flash
LilyGO's firmware back. The older T5 4.7" (H752, no "Pro") is a different board: this build is not for it.
File: MeshCore-T5EpaperPro-Cairn127-2026-11-03-full.bin
FLASH IT (Chrome or Edge on a computer)
1. Open https://espressif.github.io/esptool-js/
2. Plug the T5 in with a USB-C data cable. Click Connect and pick its port.
No port, or it won't connect: hold BOOT, press and let go of RST, let go of BOOT, then Connect again.
3. Flash Address 0x0, the -full.bin, then Program.
4. When it says done, press Disconnect, then press RST.
The first start clears the glass with a few flashes; after that, pages change without flashing.
THE CONTROLS
Touch everything. Swipe down from the top edge: the quick panel.
BOOT tap: lock and put the screen away. Hold: "Power off?". Unlock: press BOOT twice.
Side key click: screen off. Hold: lock. Double-press: unlock.
PWR turns the T5 on after a power off.
Quick panel Rotate: portrait or landscape. Clean: one flash to clear any traces on the glass.
The slider: the front light (all the way left is off).
WHAT TO TRY (with the console open: Connect in esptool-js, then the Console tab, 115200 baud; press RST
so the log starts from power-up)
1. Is the text sharp and easy to read, black on white, white on the black buttons too? A photo helps,
next to one of test 1 if you have it.
2. Rotate from the quick panel, both ways. Do taps land where you touch in both? Do pages change as
quickly as before?
3. Switch pages for a while, and sit on one for a few minutes. Any grey traces of the last page?
4. Let the screen go dark (or tap BOOT). Does it show the sleep page (time, messages, battery), and does
the time move on each minute?
5. Radio: send a message to another MeshCore node, and have it send one back.
6. GPS: outside, Settings > GNSS > GPS, on. Does it get a fix (a few minutes the first time)?
7. microSD card (FAT32) with Cairn maps: Settings > Hardware > Storage, then the Map tab. How do the
maps look?
8. Battery: is the percentage about right? Plug and unplug USB: does it show Charging and go back?
9. Battery saver: Settings > Hardware > Display > Battery saver on, Bluetooth off, USB unplugged. Leave it
dark for 10 minutes, then tap the screen or press BOOT: does it wake at once?
10. Power off: on battery, hold BOOT, choose Power off. Does the screen say "Powered off"? Press PWR for a
second: does it come back?
11. Copy everything in the console and send it (a GitHub issue, Bug report, with the build's tag),
saying what happened at each step. "It works" is a useful report too.
GOOD TO KNOW
The GPS shares the radio's power and has no standby, so "GPS off" only stops reading it. Online
updates come when the T5 joins the main release; until then, flash the next test build by hand.