ZeroBrane Studio for Vera integrates a powerful debugger that supports debugging of Lua code running on your Vera device. This simplifies writing and debugging of any Luup code you may need to work with.

  1. Start ZeroBrane Studio for Vera, select Vera interpreter if it’s not already selected (Project | Lua Interpreter), open new file (File | New), and copy the following script:

     local sunset = luup.sunset()
     luup.log(luup.version, sunset)
     print("Printed from Vera device", sunset, luup.devices[1].category_num)
     print(luup.version, os.clock(), 1)
  2. Save the script to a folder of your choice and set that folder as the current project folder (Project | Project Directory | Set From Current File).

  3. Start debugging (Project | Start Debugging).

If you run this for the first time you will be asked for a product key; use the key you received after your purchase. If you are connected to multiple devices, you will see a prompt with the list of devices that have been detected and can select one device you want to work with. The name of the device will be stored and used for subsequent debugging requests (until you restart the IDE).

When the debugger is stopped, you can set/remove breakpoints (using Project | Toggle Breakpoint), step through the code (using Step Into, Step Over, and Step Out commands), inspect variables using the Watch window (View | Watch Window), view the call stack using the Stack window (View | Stack Window), run Lua commands in the Remote console, and continue execution of your program (using Project | Continue).

You can use the Watch window to monitor variable values and expression results or quickly check the value of a variable or expression in a tooltip. The Stack window allows you to see the stack trace with local variables and upvalues shown for each stack frame.

Using remote console you can run arbitrary Lua expressions, including Luup calls, that will be executed in the context of your (suspended) script. For example, if the value of a variable count in the script is 10 and you execute count = count + 1, then the variable value will become 11, as you’d expect.

In addition to running/debugging Lua code from ZeroBrane Studio, you can also start the debugging from the device (which may be triggered by Lua code included in scenes or plugins). See the remote debugging section for details on how this can be done.

Vera functions

Several Vera-specific functions are available from the right click menu in the editor:

  1. Upload to '/etc/cmh-ludl/...' allows you to upload the current file to the device.
  2. Download '/var/log/cmh/LuaUPnP.log' retrieves the log file from the device and opens it in a new editor window.
  3. Restart Luup engine restarts the Luup engine on the device (you will see the progress and completion status in the Output window).

The first two functions are only available during the debugging. You can also upload files from the Project tree by also using the right click menu.

The results of print commands executed during debugging are “redirected” to the Output window in the IDE, which provides a convenient way of seeing the results without going through the logs.

The values you print are also pretty-printed, so you can do print(mytable) and the table content will be printed as {a = 1, b = 2} instead of table: address.


  • Debugging doesn’t start becase the IDE address is detected incorrectly. When you start debugging, the IDE may display the message with the server address: Using 'x.x.x.x' as the debugger server address. (You’ll see the message if you are using vera plugin v0.12+). If the address shown is not correct, or can’t be reached from the Vera device, the debugging is not going to work. To set the correct address, you can specify debugger.hostname = 'correct.IPaddress.or.hostname' in the configuration file and restart the IDE.

  • Debugging doesn’t start because the address of the device or the IDE is detected incorrectly. When you start debugging, the IDE will try to detect the address of the device and will use the IP address of the computer to configure the debugger. If you are running on VPN, it may cause the IDE to incorrectly detect the address of the device or the computer running the IDE. You may want to disable the VPN (and run ipconfig /renew) or configure debugger.hostname as described above to see if this resolves the issue.

  • Debugging doesn’t start because port 3480 on the device is blocked. Port 3480 on the device has to be open to allow the computer running the IDE to connect to it. To open the port, log into the vera controller from the web site and select that device.

  • Debugging doesn’t start because security settings disable potentially unsafe Lua code. If you are using Vera3, VeraLite, & VeraLite G (v1.7.1030+), VeraEdge (v1.7.3830+), VeraPlus (v1.7.3831+), or VeraSecure (v1.7.3832+), you may need to adjust the security settings to allow unsafe Lua execution for the debugging to work. You’ll find these settings at Users & Account Settings > Security. If this setting is not enabled, you are likely to see the following message in the luup logs: RunLua failed with 401/No unsafe lua allowed. See this Vera Software Update article for detals.

  • Debugging doesn’t start because of a conflict with existing Lua installation (macOS). In some rare cases the debugging doesn’t start as the system fails to load a dynamic library that has incorrect architecture. You may see a message dyld: Library not loaded: liblua.dylib or Reason: no suitable image found. Did find: /usr/local/lib/liblua.dylib: mach-o, but wrong architecture in the Output window. You may want to remove the Lua installation to resolve the conflict.

  • Debugging aborted prematurely. It has been reported that in some rare cases a debugging session may be aborted prematurely. If this happens, try to reduce the amount of logging you do (using luup.log command).

brilliant. Well worth the investment. (JoeyD)

Using ZeroBrane is a breath of fresh air! I've gained more ground on the plug-in the past few hours than I had in the previous week. I attribute that to auto-completion and the ability to debug remotely; seldom ever leaving the IDE. (aechelon)

You ROCK!!! I'm simply amazed that this worked! I didn't expect to be able to debug [register_handler and variable_watch] event types! (Shawn C)

works really well... should be very helpful to people starting-out with Lua/Luup programming for Vera scenes and plugins. (RexBeckett)

Love the debugger, saving my life. (Troy Sandal)

I have been programming computers for about 35 years and I don't think I have ever seen an environment that is easier to get started with. (Adrian)

ZeroBrane Studio has got a working debugger, full IDE feature set, small footprint, and is completely customizable in lua. (Jonathan Shieh)