Readers
The Scanner view is where you choose which PC/SC reader the app listens on. This page explains how the reader picker works, what the status bar shows, and what to do when no reader appears.
The reader picker
Section titled “The reader picker”When you open the app the Scanner view is shown. Near the top you will find a drop-down labelled Active reader. It lists every PC/SC reader that the operating system currently exposes. Reader names come directly from the PC/SC layer, so you will see the device’s official name (for example ACS ACR122U PICC Interface 00).
Select the reader you want to use. The choice is saved immediately to configuration (selected_reader) and persists across restarts — you do not need to reselect after relaunching.
To deselect the active reader, choose — no reader selected — from the top of the list.
Refreshing the reader list
Section titled “Refreshing the reader list”If you plug in a reader after the app is already open, click the Refresh button next to the drop-down. This triggers a rescan of all available PC/SC readers and updates the list. Select your reader from the refreshed list to start scanning.
Status bar
Section titled “Status bar”A thin status bar at the bottom of the window always shows the current reader state on the left side:
| Indicator | Meaning |
|---|---|
| Green dot · connected | A reader is selected and the PC/SC context reports it as available. |
| Grey dot · disconnected | No reader is selected, or the selected reader was unplugged. |
| Grey dot · Error: <message> | The PC/SC layer returned an error for the selected reader. The error text from the system is shown inline. |
The right side of the status bar shows the typing state (see Typing & Safety).
No reader found
Section titled “No reader found”If the drop-down is empty and the message No PC/SC reader found. Plug one in and click “Refresh” appears below it, the operating system cannot see any PC/SC device. Common causes:
- The reader is not plugged in.
- The reader uses a proprietary driver that is not installed.
- On macOS, the PC/SC smart card daemon may need a moment after the first plug-in; clicking Refresh usually resolves this.
- 125 kHz proximity readers are not PC/SC devices and will never appear. You need a 13.56 MHz CCID-compatible reader.
Once the reader is connected and detected, click Refresh, then select it from the list.