Live view of script variables, types, sizes and values for debugging; auto-refresh, hex view, pause/clear; may affect program performance.
How to add the Variable Watch robot skill
- Load the most recent release of ARC (Get ARC).
- Press the Project tab from the top menu bar in ARC.
- Press Add Robot Skill from the button ribbon bar in ARC.
- Choose the Scripting category tab.
- Press the Variable Watch icon to add the robot skill to your project.
Don't have a robot yet?
Follow the Getting Started Guide to build a robot and use the Variable Watch robot skill.
How to use the Variable Watch robot skill
Variable Watch refreshes frequently and can slow down your ARC project, especially if you have many skills, scripts, or variables. Use Variable Watch only when you are actively debugging.
The Variable Watch skill displays the script variables currently known to your ARC project and shows their current values. As your robot runs and scripts execute, variables change—Variable Watch automatically refreshes so you can see those changes live. This makes it useful for beginners who want to understand what their code is doing step-by-step.
What is a variable? (Beginner explanation)
A variable is a named piece of stored information. Your scripts and skills use variables to remember things like:
- a sensor reading (distance, temperature, camera status)
- a state (e.g., “is moving”, “battery low”, “tracking enabled”)
- a value you set in a script (a counter, a username, a speed value)
Variable Watch lets you see those stored values while the robot is running, which helps you confirm that your logic is working.
Main Window
1. Variable Display
This list shows each variable and details about it:
- Name – the variable’s identifier used in scripts
- Type – the kind of data it stores (example: number, text/string, etc.)
- String Size – if the value is text, this is the number of characters
- Value – the current contents of that variable
2. Clear Button
Clears your variable list back to only the default variables. This is helpful when you want to “reset” what you’re looking at and remove variables created by scripts or skills during testing.
Note: Clearing the list is mainly for debugging convenience; variables may appear again as skills/scripts run and recreate them.3. Pause Checkbox
Temporarily stops the live updating of values in the list. Use this when values are changing quickly and you need time to read them.
Tip: Pause the display right after an event happens (like a button press or sensor trigger) so you can inspect the exact values.4. Show as Hex Checkbox
Displays variable values in hexadecimal (base-16) format. This is mainly useful for advanced debugging (for example, when interpreting bytes, colors, bit masks, or low-level data).
How to use Variable Watch (Step-by-step)
-
Add the skills you plan to use to your ARC project first.
Many skills automatically create variables (for example, a camera skill may create variables for tracking data). -
Add the Variable Watch skill to your ARC project:
Project → Add Skill → Scripting → Variable WatchNote: Add Variable Watch after adding other skills. Variable Watch populates its list from variables that already exist at the time it is added. -
Run and test your project as normal.
Keep the Variable Watch window open to observe values changing in real time.
This is especially helpful when debugging issues like “Why didn’t my IF statement run?” or “Is my sensor value updating?”
Beginner debugging tips
- If the list feels overwhelming, use Clear, then reproduce the problem so you only see variables involved in that moment.
- If values are changing too fast to read, enable Pause to freeze the display.
- If ARC feels slower after adding this skill, remove Variable Watch when you are finished debugging.
