Using the Classroom App to Troubleshoot your 123 Robot

Using Device Info for Troubleshooting your 123 Robot

It can be helpful to understand the values that the built-in sensors in the 123 Robot are reporting, so that you can better understand how and why your robot's behaviors occur in a project. Within the Classroom App, the Device Info section can be used to see a visual representation of your 123 Robot's sensor data. Device info will show the 123 Robot's sensor values that are being reported in real time, so that you can use that information to help you better understand your robot's functionality, and have an additional troubleshooting tool to use if you suspect something is not working as expected.


To view a robot's device info, first select the 123 Robot you wish to view, then select 'Show Device Info'.

Eye Sensor Information


With the Device Info open, the first sensor showing data is the Eye Sensor. The Eye Sensor reports the brightness of ambient light, the color the sensor is detecting (red, blue, green, or N/A), the hue value being detected in degrees, and the proximity of the object being detected (near or far). 

This information can be used to see what the 123 Robot is detecting, so that you can make adjustments if necessary to achieve a desired behavior, like changing the ambient light in the room, or the color of the object you are trying to detect.

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The hue (third value reported for the Eye Sensor) is the numerical values for each color as reported by the Eye Sensor. The hue value ranges from 0 to 360 degrees, beginning with red and moving in rainbow order around the circular chart. At times, the hue value detected may not match the color that you see present in the environment. This can be due to the quality of the ambient light present around the sensor, and does not mean the sensor is malfunctioning.


Because color is reflected light, the ambient light (light present in the area where the sensor is used) will affect the hue value reported by the sensor. For example, a green VEX 123 Art Ring may report the number '74', which falls between the 'green' and 'yellow' areas on the Hue Chart. This is not due to a sensor malfunction, but instead due to the ambient light present around the sensor.

The hue values may read differently for different students in the same classroom, even if they are scanning the same object with the Eye Sensor. This is all dependent on the amount of light in the area where students are located. Being seated near a window, for example, or on a particularly cloudy day, may change the way the sensor reports hue value data.

If students are having an issue with their project not working as intended when using the Eye Sensor, you can check the Device Info for that robot in the Classroom App. You can work with the student to change the environment of the robot or change the object being detected to ensure the hue values from the Eye Sensor continuously read as the intended color.

Also be sure that the logic being used in students projects is correct. Learn more about coding the Eye Sensor using the Coder in this article.

Light Sensor Information


The next sensor reporting is the Light Sensor, on the bottom of the 123 Robot. The Light Sensor reports a value of light or dark based on what value it detects on the floor beneath the 123 Robot. 

This information can be useful when coding your 123 Robot to do things like line tracking activities, to make the robot follow a 'dark' or 'light' path based on this sensor's data.

Inertial Sensor Information


The built-in Inertial Sensor reports two sets of data – the first is the acceleration on the X, Y, and Z axes. Even when the 123 Robot is sitting still, these values will appear to be continually fluctuating. This is an expected behavior when the Inertial Sensor is functioning properly, as it is reporting values based on the forces acting on the robot, including gravity. 


The built-in Inertial Sensor also reports the pitch, roll, and yaw of the 123 Robot. These values change based on how the 123 Robot is being rotated in three dimensional space. When the 123 Robot is sitting still, the pitch and roll should report 0 degrees. The yaw value may change depending on the direction the 123 Robot is turned towards. 

This information can be useful to learn more about how or why your 123 Robot drives and turns accurately. You can move the 123 Robot by hand, and watch how these values change, to see how the Inertial Sensor is reporting data.

Hide Device Info


To close the Device Info, select 'Hide Device Info'.

To learn more about how to use the Device Info in the Classroom App with your VEX Coder, see this article.

For more information, help, and tips, check out the many resources at VEX Professional Development Plus

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