Driver Hub Troubleshooting

In this troubleshooting guide we will use specific language to describe different ways of power cycling the Driver Hub.
Turn Off/Power Off - Long press (1-2 seconds) the power button so that a drop down menu appears, then tap "power off" on the screen
Hard Reboot - Hold power button for at least 10 seconds and do not touch anything on the screen. Once the green LED light turns off and the screen goes dark, release the power button, and the hard reboot is complete.
Most Common Issues
Updating the OS
Unexpected Shut Down
Charging/Power
Known Software Issues
Updating the Driver Hub Operating System
When Updating your Driver Hub to the newest operating system, version 1.2.0, please be sure to follow these steps:
Install the update on a fully charged Driver Hub. If the update fails, please plug in your hub and try again after fully charging.
Don't touch the screen when a loading bar is displayed on the Driver Hub during the update process. If you touch the screen you will be directed to a menu after installation completes. Do not touch the screen and hard reboot your Driver Hub.
Once you have updated your hub, please verify that your device is showing the current version 1.2.0, in the REV Hardware Client. 
Driver Hub Intermittent Battery Power Loss
Some Driver Hubs have a slight amount of extra space inside the battery bay that may cause a loss of power or intermittent battery charging. We have two quick fix options we are suggesting as solutions. The first is to use a small piece of folded paper or a few layers of tape to provide a more secure connection between the contacts. The second is a piece of foam tape we can ship to teams which will accomplish the same goal. Suggested installation steps are highlighted below:
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Option 1: Tape Quick Fix
Tape (painters tape or masking tape) is placed on the thin edge above the battery on the side opposite the contacts
Any tape or paper  needs to sit inside the battery bay door edge
Option 2: Foam Tape
1. Cut foam tape into small pieces, approximately 2 inches or less long. The foam tape recommended is approximately 1/4 inch or less wide and 1/16 inch or less thick
2. Foam tape will be applied inside the battery case, opposite battery contacts and below the ridge that the battery door sits within.  
3. Stick foam strip in the middle, both side to side and top to bottom, of the vertical surface opposite the battery contact switch.
4. Press foam strip down firmly to make sure it sticks.
5.1 Insert battery by inserting top of battery towards foam, and gently squeezing battery towards foam with thumb until battery can easily drop into battery case.
5.2 Continue to push the battery down until it is flush in the case.
6. Done
Common Charging/Power Issue Symptoms
The symptoms listed below can have a number of causes.
Driver Hub only turns on when plugged into a charger
Battery is discharging rapidly
Battery reports low-battery at levels significantly above 0% and shuts off
Device will not boot due to low battery even when Driver Hub is charged
Driver Hub is on charger but will not turn on
Device stopped charging and will not continue to charge 
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To properly troubleshoot, please start with the steps below
1.Check the orientation of the battery - see Battery Installation 
2.Ensure you are using the charger that came with the Driver Hub - the charger must specifically be a non-PD charger for these troubleshooting steps, and using the charger that was shipped with the Driver Hub is the simplest way to confirm that.
3.Unplugging and replugging in the charger from the Driver Hub may resolve some symptoms
4.Ensure your Driver Hub is fully updated​
5.Perform a Battery Recalibration​
6.If possible, swap the battery with a known good battery to see if the issue follows the battery or follows the Driver Hub unit
The following are known issues that we are working to resolve via a future software update:
Waking Wi-Fi from a Sleep State
There is a known issue with the Wi-Fi driver not restarting correctly when the Driver Hub is woken from a "sleep" state. The current resolution is to perform a hard reboot on the device when the Driver Hub is having issues connecting to a Wi-Fi network.
You can make sure this issue doesn't happen before a match by leaving the screen on, and the Driver Station app open. This will prevent the Driver Hub from going to sleep.
Unlock Times are Inconsistent 
Unlock can take anywhere from 2-10 seconds to occur, this is normal behavior. 
Device Froze or Crashed while in Sleep Mode
Perform a hard reboot to wake up the device. This includes some cases where status LED B is solid green, indicating that the device is on, but the screen will not wake. 
Inconsistent Battery Drain
Inconsistent battery draining while in a "sleep" state is a known issue. Devices may also shut off while in a "sleep" state due to this. Future software updates are in the works to resolve this.
Additional Troubleshooting
"App Not Installed" Error
On the homepage the FTC Driver Station app can report an "app not installed" error after updating the OS and the app. This can also cause the Driver Hub to not allow you to open the FTC Driver Station app. To fix this do the following:
1.Remove the Driver Station app icon on the home page by clicking and dragging to the X icon
2.Drag the new icon from the app drawer on the home screen. The app drawer is accessed by swiping up on the home screen of the device.
Android Permissions Lock Out
If the FTC Driver Station app is locked out due to android permissions, a factory reset of the Driver Hub should resolve this issue. Please power on the device, then follow the steps below to perform a factory reset:
1.Tap the "Setting" icon
2.Tap the "System" icon
3.Tap "reset options"
4.Tap "erase all data" (factory reset)
Battery Installation
To install the battery, place it with the REV Logo facing out and the -/+ located near the contacts for the device. Add on the rear door and screw in using the included M3 hardware.
A battery that is properly installed
Battery Calibration 
We are aware of some Driver Hubs that were shipped from the factory without having their batteries properly calibrated. If you are experiencing power issues such as trouble charging or being unable to power on the device, try the following:
1.Plug Driver Hub into a charger without battery (Please use the charger that came with the Driver Hub to ensure a proper calibration)
2.Turn on Driver Hub and verify that the Driver Hub reports 100% battery charge. If the Driver Hub does not report 100% charge, you may be using a PD charger and not the one that came with the Driver Hub.
3.Install battery into Driver Hub while device is still on and charging
4.Charge for at least 8 hours and do not remove battery or charge cable
5.Remove Driver Hub from Charger
6.Hard Reboot 
Battery Verification 
After completing a battery calibration, use these steps to verify that your battery is functioning as expected.
1.Place the battery in a Driver Hub and verify that the Driver Hub turns on. 
2.Shake the Driver Hub with the screen still on and verify that the battery does not lose physical contact with the Driver Hub's contacts. If power drops, please see instructions for Unexpected Shutdown above.
3.Take note of the indicated battery charge level, charge the Driver Hub for 10 minutes, and verify that the battery charge level increased. 
4.If you have the time, perform a full charge/discharge cycle with the battery to verify that the battery behaves normally.
Connecting to Control Hub
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 Wi-Fi reset will down grade the Wi-Fi connection to 2.4GHz. If you have an android device with 5GHz you may want to switch the Wi-Fi band in order to run on 5GHz. Check out the Updating Wi-Fi Settings Section to learn more about making this switch.
External factors, such as local Wi-Fi 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 Wi-Fi band. Check out the Updating Wi-Fi Settings section to learn more about making this switch.
What is your local Wi-Fi environment like? 
Local Wi-Fi environment effects the consistency of a connection to the Control Hub. Use a Wi-Fi analyzer to check the local environment for channels that are cluttered with Wi-Fi networks. Change the Control Hubs Wi-Fi 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 Wi-Fi access points. Talk to your local Wi-Fi 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 Wi-Fi networks, try manually entering the Control Hub SSID on the Driver Hub to see if that allows you to connect.
If no networks are shown at all, you should reboot the Driver Hub. See Most Common Issues section.
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 to Wi-Fi and the Control Hub when a team member takes it home but doesn't connect consistently at school.
The Driver Hub connects to the Control Hub until you start driving the robot around.
Correlation does not equal causation of an event but is useful to take note of for further troubleshooting
Foam Tape Installation
1. Cut foam tape into small pieces, approximately 2 inches or less long. The foam tape recommended is approximately 1/4 inch or less wide and 1/16 inch or less thick
2. Foam tape will be applied inside the battery case, opposite battery contacts and below the ridge that the battery door sits within.
3. Stick foam strip in the middle, both side to side and top to bottom, of the vertical surface opposite the battery contact switch.
4. Press foam strip down firmly to make sure it sticks.
5.1 Insert battery by inserting top of battery towards foam, and gently squeezing battery towards foam with thumb until battery can easily drop into battery case.
5.2 Continue to push the battery down until it is flush in the case.
6. Done
Still Need Assistance?
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. 
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If you encounter any of these issues below, please email [email protected]
Device freezes on boot, then restarts the boot process in a loop
Device freezes on boot and never gets into the OS, even after a hard reboot
Charging and Power issues persist after multiple battery calibrations ​
Need help getting the Log Files to send to REV Support? See Downloading Log File for more information.