Distance Sensor maxxing out

The distance sensor is maxxing out. The firmware has been updated for all components, and I have copied an example Modkit program that prints the distance. Help appreciated in debugging this.


You’re not very clear on the problem you’re having. What are you trying to do? What are you seeing?

There is a maximum value that can be changed. But, there is also a limit to the sensor.


I am trying to get the distance sensor to measure and display distance. Unless I go to 2000mm or 4000mm, it maxes out at 26314, or something like that. When at either 2000mm or 4000mm, it gives numbers in the 1000mm to 2000mm region, when the distance is only 100mm or less. Also, can the mm be changed to inches? When trying to change mm, I get a popup message saying Modkit Micro may have unsaved changes.

I have read that thread. I have done the same as described, re-installed the latest firmware, and changed the max setting, and it still does not work correctly.

What I just saw on YouTube is that the distance sensor can be tested by running the remote control program. When using the controller, and the distance sensor mounted on the front, the car will not get close to a wall; it stops the car. I need to check that out tonight, as that should be a guaranteed way of checking the sensor.

I tried to do what was done on YouTube, using the drive control program with the distance sensor mounted on the front. The car ran into the wall and was not stopped by the distance sensor. Is there a specific slot I need to put the distance sensor into? I don’t recall the video mentioning a specific slot to use.

I have built the autopilot configuration. The program recognized that the distance sensor is connected, but it does not work. The car runs into the wall. I am using the new firmware 1.11, and both the brain and sensors are updated. Is there something wrong with firmware 1.11 ?


Sorry you’re having difficulty. Are you talking about this video?

If you are, your smart motors need to be in ports 1 and 6 and the distance sensor can be in ANY other port but MUST be mounted on the REAR of the robot (not the same place as it is to run the full Autopilot program). Also, it’s best not to have ANY other sensors connected to the brain for the default functionality test. Then you BACK up the robot toward the wall (or other similar solid obstacle). Note this default code is written for the motors on the Robot Base when they are spinning in the reverse direction, not forward - that’s why the sensor needs to the mounted on the back of the robot base.

Lastly, be sure you’re backing straight toward the solid obstacle because if you are emitting the sound waves at an angle toward the wall, they will bounce off at an angle and never return to the sensor. Go slowly backing up to get a good feel for it and let us know if you experience further difficulty.

Thanks for the reply. I have done all the above and the sensor didn’t work. I then went to the AutoPilot program and the distance sensor does not work. It does not stop the robot car from bumping the wall. The program recognizes that the sensor is there, but it doesn’t function correctly. I have the latest firmware 1.11 and all sensors have been updated as well. I am using Modkit. What do you suggest trying now?

Hi Lynn,

We’re sorry that you are having this problem. Please contact our VEX Technical Support team at support@vex.com or call us at 1-903-453-0802 so we can provide additional help to resolve this problem.


  • Art