Wi-Fi Scan
Connect two devices on the same Wi-Fi network by scanning a code, then send messages between them.
Wi-Fi Scan links two REDENES devices that are joined to the same local network. Your device displays a QR code built from its own Wi-Fi address and begins listening for connections; you join another device by scanning the code on its screen. Once linked you can exchange text messages across the local network and watch them arrive in a timestamped log. No internet connection is needed — only a shared network.
Overview
| Control | What it does |
|---|---|
| QR code image | A code built from your device's Wi-Fi address, generated when the screen opens |
| Status label | Not Connected, or Connected to ip: followed by the other device's address |
| Connect / Disconnect | One button; its label flips with the connection state |
| Received text area | A timestamped log of received messages, newest at the bottom |
| Send field | Where you type a message |
| Send button | Delivers the typed message and clears the field |
Every device on this screen does two things at once: it listens for incoming connections, and it can reach out to another device by scanning. That is why only one side needs to scan.
Getting Here
- Open the Account tab.
- Open App Settings.
- Choose Wi-Fi Scan.
This row is limited to certain agencies. If Wi-Fi Scan is not in App Settings, it is not enabled for the agency you are in.
Loading and Empty States
| State | What you see |
|---|---|
| Screen opens with Wi-Fi joined | A QR code appears immediately and the status reads Not Connected |
| Screen opens with no Wi-Fi | No QR code is drawn, because the device has no Wi-Fi address to encode |
| Listening | No separate indicator — the device is always listening while the screen is open |
| Connected | The status shows the other device's address and the button reads Disconnect |
Connecting to Another Device
- Make sure both devices are joined to the same Wi-Fi network. This will not work across different networks, and it will not work over mobile data.
- Open Wi-Fi Scan on both devices so both are listening and both show a code.
- On the device that will scan, tap Connect.
- Grant camera access if prompted.
- Point the camera at the other device's QR code. The status changes to show the connected address and the button becomes Disconnect.
- Your device immediately sends a greeting containing your own address, so the other device's received log shows that you connected, along with the time.
Guest Wi-Fi and many public networks block devices from reaching each other even when both are joined. If pairing fails on a network like that, use a hotspot you control, or use Bluetooth Scan, which does not need a network at all.
Sending a Message
- Type your text in the Send field.
- Tap the send button. The keyboard closes, the message is sent, and the field clears.
- If you did the scanning, your message goes to the device you scanned. If you were the one scanned, your message goes to everyone currently connected to you.
- An empty field sends nothing.
Received messages are appended to the log prefixed with the date and time in dd-MM-yyyy HH:mm:ss form. The log keeps growing for as long as the screen is open.
Because each device is also listening, more than one device can connect to yours at the same time. Messages you send then go to all of them.
Disconnecting
- Tap Disconnect. Your device sends a short notice containing your address and the word Disconnected, closes the link, and resets the status to Not Connected.
- The other device sees that notice in its received log.
- Leaving the screen with the back button returns you to App Settings.
Which Side Does What
The two devices are not symmetrical once they are linked, and that shapes where your messages go.
| Role | How you got it | Who your messages reach | What Disconnect does |
|---|---|---|---|
| The scanner | You tapped Connect and scanned the other code | Only the device you scanned | Ends your one link |
| The scanned | Someone scanned your code | Everyone currently connected to you | Ends the links you hold |
Both sides keep listening while the screen is open, which is why a third device can join the one that was scanned.
For a straight two-way conversation, have one person scan and then leave it alone. If several people scan the same device, that device becomes the hub and its messages go to all of them at once.
Comparing the Device-to-Device Tools
| Wi-Fi Scan | Bluetooth Scan | Bluetooth Terminal | |
|---|---|---|---|
| Talks to | Another REDENES device | Another REDENES device | Bluetooth serial hardware |
| Needs a network | Yes, a shared Wi-Fi network | No | No |
| Needs internet | No | No | No |
| How you link | Scan the other device's code | Scan the other device's code | Tap Connect on a list row |
| Identifies the other side by | Its Wi-Fi address | Name and agency | Name and identifier |
| Can send a large file | No | Yes, with a progress ring | No |
| More than two devices | Yes, on the scanned side | No | No |
Choose Wi-Fi Scan when both devices are already on a station or vehicle network and you want a quick text link. Choose Bluetooth Scan when there is no usable network at all, or when you need to move a file.
How This Connects
- Where the data comes from. Messages travel directly between devices across your local network. Nothing reaches your agency's servers, and no message is stored anywhere after you leave the screen.
- What identifies you. Your Wi-Fi address, read from the device itself. If the device leaves and rejoins a network its address can change, which invalidates the QR code the other side scanned.
- Nothing is saved. These messages are not chat messages. They do not appear under Messages and are not logged as notifications.
- The other device-to-device tools. Bluetooth Scan does the same job without any network and can also send a large file with a progress ring. Bluetooth Terminal is for serial hardware, not other REDENES devices.
- Not the QR builder. Wi-Fi QR Code creates codes for other people to scan with their phone's camera to join a network. It has nothing to do with the pairing code on this screen.
- Permissions. Camera access is needed to scan, and local network access is needed to reach the other device. You can confirm what a device has granted from its detail card on Devices.
- Offline and reconnect. Works with no internet at all, as long as both devices share a network. There is no automatic reconnect: if the link drops, or either device changes network, tap Connect and scan the current code again.
Troubleshooting
| If this happens | What to do |
|---|---|
| No QR code appears | The device is not joined to Wi-Fi, so it has no address to encode. Join a network and reopen the screen. |
| The camera does not open when you tap Connect | Camera access was denied. Grant camera permission for REDENES in your device's settings, then retry. |
| The code scans but the status never changes | The two devices are not on the same network, or the network blocks device-to-device traffic. Confirm both networks match, then try a hotspot you control. |
| Local network access was refused | Allow local network access for REDENES in your device's settings; without it the app cannot reach the other device. |
| The status shows an address but messages never arrive | The other device may have left the screen, which stops it listening. Have it reopen Wi-Fi Scan, then reconnect. |
| Pairing worked earlier but fails now | The other device's address changed when it rejoined the network. Scan its current code rather than an old photo of it. |
| The received log is empty when you return | Nothing is saved. Leaving the screen clears the log. |
| Messages reach a device you did not expect | You were the side that was scanned, so your messages go to every device connected to you. Disconnect and reconnect with only the device you want. |
| Wi-Fi Scan is not in App Settings | The row is limited to certain agencies. Use Bluetooth Scan instead. |
Related Pages
⬅️ Previous: Bluetooth Terminal | Next: Wi-Fi QR Code ➡️