Thanks - ARC still supports the EZB v3, so you do not strictly have to upgrade to a newer EZB. Most EZB v3 connectivity problems on modern Windows 10/11 machines are caused by Bluetooth pairing/driver issues (many cheap dongles are BLEonly and don’t provide the Serial Port Profile), incorrect COM selection/baud, or power/LED state on the EZB itself.

Here’s a focused checklist and stepbystep troubleshooting procedure to get your v3 talking to ARC.

Helpful docs

• EZB v3 (device/firmware): https://synthiam.com/Support/Hardware/EZ-B-v3
• Connection troubleshooting (general): https://synthiam.com/Support/troubleshooting/Connection-Troubleshooting
• USB/Serial troubleshooting: https://synthiam.com/Support/troubleshooting/Troubleshoot-USB-Connections

Stepbystep troubleshooting

1. Verify EZB powers up

• Power the EZB with a known good battery or power supply.
• Listen/observe for startup sound or any LED activity. Note LED states (solid, flashing).
• If no LEDs/sound, check power source and battery voltage.

2. Confirm your Bluetooth dongle supports Bluetooth Classic (SPP)

• Many modern USB dongles are BLE only and cannot create a Serial COM port. Windows 11 pairing UI will show the device but not provide a COM port.
• If you only have a BLE dongle, you must use a Bluetooth Classic dongle or connect the EZB by other means (USB/serial or a WiFi capable controller).

3. Pair EZB in Windows BEFORE connecting in ARC

• Open Windows Settings Bluetooth & devices Add device Bluetooth. Pair the EZB device.
• If prompted for a PIN, try 1234 (common default) or check your EZB v3 documentation.
• After pairing, open Device Manager:
  • Check under "Ports (COM & LPT)" for a "Standard Serial over Bluetooth link (COM#)" or similar.
  • Alternatively check under the Bluetooth device’s Services for RFCOMM COM ports.

4. Note the COM port number and test with a terminal

• Use Device Manager to find the COM number (COM3, COM4, etc.).
• Use a terminal app (PuTTY, Tera Term) to open that COM with common baud rates (try 115200, 57600, 38400, 19200, 9600). EZB v3 often uses higher speed (try 115200).
• If you see garbage/unresponsive, try different baud rates. If the port won’t open at all, the driver or pairing is at fault.

5. Configure ARC Connection skill

• Open ARC, Project Add robot skill EZB Connection (if not already added).
• Press CONFIG (kebab/hamburger) for the Connection control and set the COM port to the one you found.
• Try Connect0 (the Connect button in the skill). Or run this script command:

// Attempt connect and print status (ARC JavaScript)
controlCommand("Connection", "Connect0");
var connected = controlCommand("Connection", "GetStatus", 0);
print("EZB connected? " + connected);

• If Connect fails, check ARC’s Status window (bottom of ARC), press COPY and paste the contents somewhere - it will show the error details.

6. If Windows never shows a COM port

• Most likely your Bluetooth dongle does not expose SPP. Try a different dongle known for Classic Bluetooth (USB dongles supporting Bluetooth 2.1/3.0/4.0 Classic, not BLE-only).
• Alternatively use a wired serial/USB connection if your EZB hardware supports it, or use a WiFi based EZB (if you decide to upgrade).

7. Common gotchas

• Make sure ARC is not already connected to the COM port via another app.
• In Device Manager Ports, right click Properties Port Settings Advanced make sure COM number isn’t conflicting with something else.
• Some drivers need native Windows Bluetooth (not manufacturer apps). Remove vendor Bluetooth manager if it interferes.
• If the EZB was configured to accept connections only from a previously paired device, try clearing paired devices and pairing fresh.

If those steps still fail, please send:

• What you see in Device Manager (the exact device name and COM# if any).
• The Bluetooth USB dongle make/model (or product link).
• The EZB LED behavior at power up.
• The ARC Status window copy (press COPY on the ARC status bar and paste here). With those I can guide the next steps (driver fixes, alternate connection methods, or ARC configuration tweaks).

Would you like the exact location in ARC to set DTR/RTS or show where to find the Connection control’s settings (kebab menu)?

Good luck! I hope you get connected. As @Athena said, the V3 should work with ARC. However your windows OS and the Bluetooth you're using may need attention. One of then is most like the problem. The old V3 was a super nice piece of hardware. @DJ did an awesome job designing that little marvel. I loves the face it has a voltage converter in it that natively gave us 5vdc to the power pin in the digital header pins. You won't get that feature with the new V4x2 eZB. However the V4 is a superior device.

Also, have you had a chance to read the Support page for the V3? There's a great video showing each step on connecting the V3 over Bluetooth. It is showing how to connect through an older version of Windows but I'm sure you can navigate through you're new Win 11.

Here's the link if you need it: https://synthiam.com/Support/Hardware/EZ-B-v3

Have fun!!! 

Thanks - Dave’s note is right: the EZ-B v3 still works with ARC, but modern Windows + USB/Bluetooth dongles are the usual culprits. Below is a focused checklist and stepbystep you can follow. If anything is unclear I’ll walk you through it and help diagnose from the ARC status output or Device Manager details.

Useful links

• EZB v3 support page: https://synthiam.com/Support/Hardware/EZ-B-v3
• Connection troubleshooting: https://synthiam.com/Support/troubleshooting/Connection-Troubleshooting
• USB/Serial troubleshooting: https://synthiam.com/Support/troubleshooting/Troubleshoot-USB-Connections

Step-by-step troubleshooting

1. Verify EZB powers up

• Power the EZB with a known-good battery or power supply.
• Observe LEDs / listen for startup sound. If no LEDs/sound, check battery voltage and wiring first.

2. Confirm your Bluetooth dongle supports Bluetooth Classic (SPP)

• Many modern USB dongles are BLEonly (no Serial Port Profile) and will NOT create a COM port for the EZB.
• If your dongle is BLE-only you’ll need a Bluetooth Classic dongle (look for Bluetooth 2.1/3.0/4.0 "Classic" or "SPP" support).

3. Pair the EZB in Windows first

• Open Windows Settings Bluetooth & devices Add device Bluetooth and pair the EZB.
• Common PIN: try 1234 if prompted.

4. Check Device Manager for the COM port

• Open Device Manager Ports (COM & LPT). Look for "Standard Serial over Bluetooth link (COM#)" or similar.
• If you do NOT see a COM port, the dongle isn’t exposing SPP. If you see the device but no COM, open the Bluetooth device properties Services and look for Serial/RFCOMM.

5. Test the COM port with a terminal (helps rule out ARC)

• Use PuTTY or Tera Term to open the COM port at common baud rates (try 115200, 57600, 38400, 19200, 9600).
• EZB v3 commonly uses higher speeds (try 115200 first).
• If the port won’t open or you can’t get any response at any baud, the pairing/driver is the issue.

6. Configure the ARC Connection skill (kebab menu)

• In ARC, open your project and ensure you have the EZB Connection skill added.
• Open the Connection skill settings (click the three-line kebab/hamburger on the top-right of the skill window).
• Under the COM/USB Connection settings set the correct COM port and Baud rate. If available, try toggling DTR/RTS checkboxes (some devices need these).
• Save and press the Connect button for slot 0 (or use the Connect0 button inside the skill).

7. Try connecting via ARC script (quick test)

• Run this JavaScript in ARC (use the Script control):

controlCommand("Connection", "Connect0");
var connected = controlCommand("Connection", "GetStatus", 0);
print("EZB connected? " + connected);

• If it returns false, check the ARC Status window (bottom). Press COPY on the ARC status bar and paste the contents here.

8. If Windows never shows a COM port

• Most likely your USB dongle is BLE-only. Try a known Bluetooth Classic USB dongle.
• Alternatively connect by wired serial/USB (if you can) or consider a Wicapable EZB (e.g., EZB v4) if you want modern WiFi support.

Common gotchas & fixes

• Another app (or previous ARC instance) already opened the COM port - close other apps.
• Conflicting COM number: in Device Manager Ports Properties Port Settings Advanced, change the COM number if there’s a conflict.
• Some vendor Bluetooth stack software can interfere - try using Windows’ builtin Bluetooth stack (uninstall vendor manager if necessary).
• Re-pair the EZB: remove old pairings both on Windows and on the EZB, then pair again.

If you still can’t connect, please provide

• Exact Bluetooth USB dongle make/model (or a link).
• What appears in Device Manager (exact device name and COM#, if any).
• EZB LED behavior at power-up (which LEDs are on / flashing).
• The ARC Status output (press COPY on the ARC Status bar and paste here).
• The baud rates you tried (and whether a terminal app could open the port).

If you want I can:

• Walk you through checking Services in the Bluetooth properties to confirm RFCOMM/SPP is enabled.
• Show exactly where to set the COM port, baud, and DTR/RTS in the Connection skill kebab menu.
• Recommend a specific Bluetooth Classic dongle that’s known to work with Windows 10/11 and ARC.

Would you like step-by-step screenshots for the Connection skill settings (where to find the kebab menu and COM/USB settings), or do you want to post the ARC Status + Device Manager details now so I can diagnose further?