Added brltty note

Signed-off-by: simonmicro <[email protected]>

docs/firmware/troubleshooting.md

@@ -6,22 +6,29 @@ We have seen a number of "charge only" cables in the community. Try to upload us
 
 ## Check the driver
 
-Check the driver insertion.
+On non-Linux machines you may need to install additional drivers, as noted in the [Getting Started](getting_started.md) guide.
+
+### Driver is there, but device is busy
+
+On Linux, you may need to remove the `brltty` package to free up the serial port.
+
+```bash
+sudo apt-get remove brltty
+```
+
+!!! info "What is brltty?"
+    `brltty` is a daemon that provides access to the Linux/Unix console (text mode) for a blind person using a refreshable braille display. It is not needed for most users, but is annoyingly always claiming all available serial ports.
 
 ## Arduino_TFT.h: No such file or directory
 
 You did not clone the repository with the `--recursive-submodules` flag.
 
 !!! note "Tip"
-    After changing or updating/pulling a branch, run the command again to also update dependencies:
-    ```bash
-    git pull
-    git submodule update --init --recursive
-    ```
+    After changing or updating/pulling a branch, run the commands notes inside the `README.md` to update the submodules and the PlatformIO packages.
 
 ## Failed to connect to ESP32: Timed out waiting for packet header
 
-You did not hold down BTN1(FLASH) and then tap the RESET button on the watch whilst platform.io was trying to connect.
+You did not hold down BTN1(FLASH) and then tap the RESET button on the watch whilst PlatformIO was trying to connect.
 
 ## Fixing `error: unknown type name ‘wait_queue_t’; did you mean ‘wait_event’?`