From e760fdc653bb8f073eb6db76006fe9df23de8de1 Mon Sep 17 00:00:00 2001
From: Justin Oros <JustinOros@gmail.com>
Date: Wed, 1 Apr 2026 18:34:52 -0700
Subject: [PATCH] Update README.md

---
 README.md | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/README.md b/README.md
index f4d3479..2a8f9a6 100644
--- a/README.md
+++ b/README.md
@@ -78,6 +78,18 @@ xteink-plugins/
         └── SmallerFontsSettingsPage.h/.cpp # Settings UI activity
 ```
 
+## Troubleshooting
+
+### Linux: Permission denied when flashing
+
+If you see an error like `Could not open /dev/ttyACM0, the port is busy or doesn't exist` or `Permission denied`, your user needs to be added to the `dialout` group:
+
+```bash
+sudo usermod -aG dialout $USER
+```
+
+Log out and log back in for the change to take effect, then re-run `install.py`.
+
 ## Adding a Plugin
 
 1. Create a new directory under `plugins/` with your plugin's name.