Better port permission setup and errors

README.md

@@ -38,7 +38,15 @@ Optionally there are is also a [Python script](python.md).
 
 For device specific commands, see their individual documentation pages.
 
-Common commands:
+###### Permissions on Linux
+To ensure that the input module's port is accessible, install the `udev` rule and trigger a reload:
+
+```
+sudo cp release/50-framework-inputmodule.rules /etc/udev/rules.d/
+sudo udevadm control --reload && sudo udevadm trigger
+```
+
+##### Common commands:
 
 ###### Listing available devices
 

inputmodule-control/src/inputmodule.rs

@@ -388,12 +388,17 @@ fn simple_cmd_multiple(serialdevs: &Vec<String>, command: Command, args: &[u8])
 }
 
 fn simple_cmd(serialdev: &str, command: Command, args: &[u8]) {
-    let mut port = serialport::new(serialdev, 115_200)
+    let port_result = serialport::new(serialdev, 115_200)
         .timeout(SERIAL_TIMEOUT)
-        .open()
-        .expect("Failed to open port");
+        .open();
 
-    simple_cmd_port(&mut port, command, args);
+    match port_result {
+        Ok(mut port) => simple_cmd_port(&mut port, command, args),
+        Err(error) => match error.kind {
+            serialport::ErrorKind::Io(std::io::ErrorKind::PermissionDenied) => panic!("Permission denied, couldn't access inputmodule serialport. Ensure that you have permission, for example using a udev rule or sudo."),
+            other_error => panic!("Couldn't open port: {:?}", other_error)
+        }
+    };
 }
 
 fn open_serialport(serialdev: &str) -> Box<dyn SerialPort> {

release/50-framework-inputmodule.rules

@@ -0,0 +1,8 @@
+# Framework Laptop 16 - LED Matrix
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="32ac", ATTRS{idProduct}=="0020", MODE="0660", TAG+="uaccess"
+
+# B1 Display (Experimental prototype, not a product)
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="32ac", ATTRS{idProduct}=="0021", MODE="0660", TAG+="uaccess"
+
+# C1 Minimal Microcontroller Module (Template for DIY Module)
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="32ac", ATTRS{idProduct}=="0022", MODE="0660", TAG+="uaccess"