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Troubleshooting the Control System
One of the key aspects of troubleshooting is understanding the most common issues that occur in a system. Once those problems, and their indicators, are defined a flow has to be created. For example, a check engine light in a car indicates any number of issues. When a cars check engine light comes on, a mechanic pulls the codes from the car to narrow down the issue to a specific part of the engine. Even if the code leads to a specific part of the engine, like the transmission, it is not always indicative of the exact problem. However, there is a process flow. Each step narrows down the problem to a potential solution. Troubleshooting the REV Control system is no different!
The status LED is the REV Control System equivalent to the check engine light mentioned in the example. Visit the LED Blink Code section to understand what each code is and what it indicates.
Many issues can be solved by systematic troubleshooting without needing to contact REV Support. Take a look at the troubleshooting tips below for help in determining the cause of the issue you are seeing. Should you need to contact us, describing the steps you've taken in detail will help us get you up and running quickly. The section is divided into general best practices, Control Hub (REV-31-1595) troubleshooting and Expansion Hub (REV-31-1153) troubleshooting.

General Best Practices

Before diving into common troubleshooting paths its important to understand the general guidelines, or best practices, for Control System Health.
    Charge the Battery - While a charged battery and phone are crucial to a healthy control system in general; it is also helpful to ensure batteries and phones are charged before a match.
    Update - The applications, firmware, and operating system have periodic updates to improve the control system. Keeping the control system up to date ensures the best performance!
    Isolate the Issue - This is key to effective troubleshooting. Many issues can show the same symptom, so eliminating failure points one at a time is critical to finding the root cause.
DO NOT plug a battery charger into either the Control Hub or Expansion Hub. It will damage the Hub and cause eventual device failure
Maintaining and taking care of the 12V Slim Battery is also important for troubleshooting purposes. All rechargeable batteries have a finite lifespan however following the best practices for the 12V Slim Battery can extend the lifespan of the battery.

Control Hub Troubleshooting

The following questions consider common indicators of issues seen in the Control Hub. Think about the potential indicators your Hub is currently exhibiting and consider the following questions:
Is the Driver Station device unable to connect to to the Control Hub WiFi?
Yes
Is the Driver Station connected to the WiFi but not showing a ping or any other signs of communication?
Yes
Has the Status LED been solid blue for longer than 30 seconds (after start up)?
Yes

Can't Connect the Control Hub to a Computer

The WiFi reset will down grade the WiFi connection to 2.4GHz. If you have an android device with 5GHz you may want to switch the WiFi Band in order to run on 5GHz. Check out the Updating WiFi Settings Section to learn more about making this switch.
External factors, such as local WiFi environment, play a part in the ability to establish or maintain a connection between a Control Hub and a computer. Like all aspects of of troubleshooting its important to isolate an issue by asking questions and discovering the answers! As you work on troubleshooting consider the following questions:
    What is your local WiFi environment like?
      Local WiFi environment effects the consistency of a connection to the Control Hub. Use a WiFi analyzer to check the local environment for channels that are cluttered with WiFi networks. Change the Control Hubs WiFi channel to a channel with the least amount of overlap with other networks.
    Are you connected to another WiFi network?
      The Control Hub produces a non internet WiFi connection. Settings on the individual computer may cause the device to jump to a local, remembered network that produces an internet connection.
    Are you in a school or a place of business?
      In addition to the amount of local networks in an environment its important to understand what those local networks are capable of. For instance, some school districts have security measures in place that block unauthorized WiFi access points. Talk to your local WiFi adminstrator to find out what you need to get the Control Hub as an approved network.
If the Control Hub SSID is not shown in the list of available WiFi networks, try manually entering the Control Hub SSID to see if that allows you to connect.
Contact REV Support with details of the troubleshooting information you have collected such as the answers to the questions above and the outcome of your troubleshooting thus far. It will also help to send logs or other diagnostic data to REV Support.
Need help getting the Log Files to send to REV Support? See Downloading Log File for more information.

Driver Station Won't Connect

Information in this flowchart is for the initial bring up of connecting the Control Hub with a Driver Station. For issues with intermittent connection or periodic connection drops please check out the information below this flowchart.
The WiFi reset will down grade the WiFi connection to 2.4GHz. If you have an android device with 5GHz you may want to switch the WiFi band in order to run on 5GHz. Check out the Updating WiFi Settings Section to learn more about making this switch.
External factors, such as local WiFi environment, play a part in the ability to establish or maintain a connection between a Control Hub and a Driver Station device. Like all aspects of of troubleshooting its important to isolate an issue by asking questions and discovering the answers! As you work on troubleshooting consider the following questions:
    Is your system operating on a 2.4 GHz band or 5GHz band?
      REV recommends, if you have a dual band Driver Station device, that you operate on the 5GHz WiFi band. Check out the Updating WiFi Settings section to learn more about making this switch.
    What is your local WiFi environment like?
      Local WiFi environment effects the consistency of a connection to the Control Hub. Use a WiFi analyzer to check the local environment for channels that are cluttered with WiFi networks. Change the Control Hubs WiFi channel to a channel with the least amount of overlap with other networks.
    Are you in a school or a place of business?
      In addition to the amount of local networks in an environment its important to understand what those local networks are capable of. For instance, some school districts have security measures in place that block unauthorized WiFi access points. Talk to your local WiFi administrator to find out what you need to get the Control Hub as an approved network.
    Does the the Driver Station connect to the Control Hub until a mechanism is run?
      Certain mechanisms draw enough power from the Control Hub to put a strain on the battery. If you notice a drop in displayed voltage when you start a code, or when a particular mechanism is run, this may be indicative of a brown out condition. Other indicators include:
        The Driver Station throwing errors about power to the system
        The Driver Station making a disconnect sound
        The voltage on the Driver Station showing 9 volts or lower when running code
        Motors running at lower speeds then what they have been set to run
      To remedy this issue check out our instructions on proper battery care.
If the Control Hub SSID is not shown in the list of available WiFi networks, try manually entering the Control Hub SSID on the Driver Station to see if that allows you to connect.
If you are still experiencing connection issues, once you have gone through the flowchart and worked on addressing the potential root of connection issues describe in the list above, start looking for patterns in the behavior. How often does this behavior appear? Are there certain things that happen around the same time the disconnects happen? The following list provides some ideas on what sort of patterns you might see:
    The Control Hub connects fine when a team member takes it home but doesn't seem to like to connect at school.
    The Control Hub connects fine until you start driving the robot around.
Just remember correlation does not equal causation of an event but is useful data to further troubleshooting
Contact REV Support with details of the troubleshooting information you have collected such as the answers to the questions above and the outcome of your troubleshooting thus far. It will also help to send logs or other diagnostic data to REV Support.
Need help getting the Log Files to send to REV Support? See Downloading Log File for more information.

Status LED is Solid Blue for Longer than 30 Seconds

This section is for troubleshooting a Control Hub. If you have an Expansion Hub please refer to the Expansion Hub Troubleshooting guide for help solving Expansion Hub related issues.
The status LED on the Control Hub is similar to a check engine light on a car. A solid blue status LED indicates the Robot Controller is not communicating to the I/O of the Control Hub, but not what the root cause is. Updating the Control Hub to the latest version of all the software is a first step to resolving this issue. Below are two ways to update depending on what

Using the REV Hardware Client

The REV Hardware Client is software designed to make managing REV devices easier for the user. This Client automatically detects connected device(s), downloads the latest software for those device(s), and allows for seamless updating of the device(s). Using the REV Hardware Client allows you to perform any required updates that may be needed to recover your Control Hub. The Hardware Client can also be used to Send Diagnostic Data to REV.
If you do not have a Windows 10 or higher PC, see Downloading Log File for more options on getting your diagnostic data to REV, and Updating Firmware, Updating Operating System, and Updating Robot Controller Application for steps to update the software.

Using Android Studio

The Control Hub must run version 5.0 or higher of the Robot Controller Application. If using Android Studio, make sure you are using a 5.0 or higher project.
If you use Android Studio for coding you will need to update your Robot Controller application by creating a new Android Studio project with the most recent version of the Robot Controller APK. Information on this process can be found in FTC Wiki Android Studio Tutorial.
If your issue persists after going through this guide, contact REV Support with details of the troubleshooting information you have collected such as the answers to the questions above and the outcome of your troubleshooting thus far. It will also help to send logs or other diagnostic data to REV Support.

Expansion Hub Troubleshooting

The following sections, "Common Indicators and their Solution Steps," provides common indicators of issues seen in the Expansion Hub. Think about what the potential indicators your Hub is currently exhibiting and consider the following questions:
    Did you perform a firmware update before the Hub began to have issues?
    What is the behavior of the Status LED on the Expansion Hub?
    Is the Driver Station showing an error message 'Cant find the Expansion Hub Portal"?
    Did the Robot Controller app open when you plugged in the RC phone and gave power to the Hub?
    Are you experiencing issues with communication between a primary and secondary Hub?
If a path in this guide does not resolve the issue please contact REV Robotics Support at [email protected]

Common Indicators and their Solution Steps

Issues Seeing a Secondary Expansion Hub

The steps below utilize information provided in the Adding an Expansion Hub article. Use this article to help you navigate as you run through the troubleshooting flowchart.
To update a Robot Controller check out the article on Updating the Robot Controller Application.
If you are attempting to connect two Expansion Hubs together please confirm that the first Expansion Hub is connected to the Robot Controller. From there change the Expansion Hub address. For information on how to change the Expansion Hub address check out the FTC Wiki Using a Second Expansion Hub article.

Firmware Update

USB Serial Converter Check

    1.
    Plug your Expansion Hub into a Windows PC
    2.
    Open the Device Manager in Settings
    3.
    Click the arrow next to Universal Serial Bus Controllers
    4.
    Find USB Serial Converter under the menu
    5.
    If this is not present there maybe a larger issue with your hub. Email [email protected] with details of the steps you have taken so far,and any order numbers for the Expansion Hub (if you have them)
If you are using a Mac you can use System Information in Lion or later (or System Profiler in Snow Leopard and earlier versions of Mac OS) in Spotlight (press ⌘ and Space ). The program is in /Applications/Utilities and is the tool to see the connected USB devices and other hardware details.

Hub Startup Procedures

    1.
    Unplug the USB from your RC phone
    2.
    Power off the main robot switch (turn off 12V power from the Expansion Hub(s))
    3.
    Wait a few seconds
    4.
    Turn on the Main Robot Switch (supply 12V power to the Expansion Hub(s))
    5.
    On your RC phone, press the square button and the swipe to close the FTC RC app
    6.
    Plug your RC phone into the USB-- the FTC app should automatically open
      1.
      If the app doesn't automatically open you do not have a good connection from the Expansion Hub to the Phone. Check your cables first, followed by the micro and mini USB connections.
      2.
      Consider using some form of strain relief (like the REV USB Retention Mount or one of the many 3d printable options available on places like Thingiverse) to keep the USB-mini port from being damaged.
If the issues persists after applying the Retention Mount try running through the Firmware Update procedure.

Driver Hub Troubleshooting

Driver Hub Won't Connect

Information in this flowchart is for the initial bring up of connecting the Control Hub with a Driver Hub. For issues with intermittent connection or periodic connection drops please check out the information below this flowchart.
The WiFi reset will down grade the WiFi connection to 2.4GHz. If you have an android device with 5GHz you may want to switch the WiFi band in order to run on 5GHz. Check out the Updating WiFi Settings Section to learn more about making this switch.
External factors, such as local WiFi environment, play a part in the ability to establish or maintain a connection between a Control Hub and a Driver Station device. Like all aspects of of troubleshooting its important to isolate an issue by asking questions and discovering the answers! As you work on troubleshooting consider the following questions:
    Is your system operating on a 2.4 GHz band or 5GHz band?
      REV recommends, if you have a dual band Driver Station device, that you operate on the 5GHz WiFi band. Check out the Updating WiFi Settings section to learn more about making this switch.
    What is your local WiFi environment like?
      Local WiFi environment effects the consistency of a connection to the Control Hub. Use a WiFi analyzer to check the local environment for channels that are cluttered with WiFi networks. Change the Control Hubs WiFi channel to a channel with the least amount of overlap with other networks.
    Are you in a school or a place of business?
      In addition to the amount of local networks in an environment its important to understand what those local networks are capable of. For instance, some school districts have security measures in place that block unauthorized WiFi access points. Talk to your local WiFi administrator to find out what you need to get the Control Hub as an approved network.
    Does the the Driver Hub connect to the Control Hub until a mechanism is run?
      Certain mechanisms draw enough power from the Control Hub to put a strain on the battery. If you notice a drop in displayed voltage when you start a code, or when a particular mechanism is run, this may be indicative of a brown out condition. Other indicators include:
        The Driver Hub throwing errors about power to the system
        The Driver Hub making a disconnect sound
        The voltage on the Driver Hub showing 9 volts or lower when running code
        Motors running at lower speeds then what they have been set to run
      To remedy this issue check out our instructions on proper battery care.
If the Control Hub SSID is not shown in the list of available WiFi networks, try manually entering the Control Hub SSID on the Driver Hub to see if that allows you to connect.
If you are still experiencing connection issues, once you have gone through the flowchart and worked on addressing the potential root of connection issues describe in the list above, start looking for patterns in the behavior. How often does this behavior appear? Are there certain things that happen around the same time the disconnects happen? The following list provides some ideas on what sort of patterns you might see:
    The Driver Hub connects fine when a team member takes it home but doesn't seem to like to connect at school.
    The Driver Hub connects fine until you start driving the robot around.
Just remember correlation does not equal causation of an event but is useful data to further troubleshooting
Contact REV Support with details of the troubleshooting information you have collected such as the answers to the questions above and the outcome of your troubleshooting thus far. It will also help to send logs or other diagnostic data to REV Support.
Need help getting the Log Files to send to REV Support? See Downloading Log File for more information.
Last modified 2mo ago