Power On

Now that the device is wired and the connections carefully checked, power on the robot. You should see the SPARK Flex slowly blinking its light for a new device; the color will be Magenta. If the LED is dark or you see a different blink pattern, refer to the Status LED guide for troubleshooting.

Connect to the SPARK Flex

Basic Setup and Configuration

Before any parameters can be changed, you must first assign a unique CAN ID to the device. This can be any number between 1 and 63. After setting a unique CAN ID, the user interface will refresh and allow you to change other parameters.

Set the Motor Type

If you are using a NEO or NEO 550, verify that the motor type is set to REV NEO Brushless, Sensor Type is Hall Effect, and the LED is blinking Magenta or Cyan.

Limiting Current

There are two ways to protect your robot’s motors from electrical damage in high-current situations: Circuit Breakers and the SPARK Flex’s Smart Current Limit Setting. To protect your motors from currents that are too high, it is best practice to limit your current both with the SPARK Flex’s Smart Current Limit and an appropriately rated circuit breaker.

Circuit breakers, while an extremely important part of a robot's wiring and safety, are only designed to trip at a specific temperature, after a set amount of time, to protect the electrical system from fire or other electrical hazards. Due to this, we recommend setting a Smart Current Limit to protect your motors from damage due to high currents.

The SPARK Flex Motor Controller includes a Smart Current Limit feature that can adjust the applied output to the motor to maintain a constant phase current.

Out of the box, the SPARK Flex's Smart Current Limit default setting is 80A for any motor that you use. We recommend utilizing our or the table below to decide what to set your Smart Current Limit to for your robot.

Your ideal current limit may vary based on your specific application, but these values can be used as a starting point to reduce the chance of an overload on your motor as you begin tuning your specific mechanism's Smart Current Limit.

The settings must be saved for the SPARK Flex to remember its new configuration through a power cycle. To do this, press the Persist Parameters button at the bottom right of the page. It will take a few seconds to save, indicated by the loading symbol on the button.

Any settings saved this way will be remembered when the device is powered back on. You can always restore the factory defaults if you need to reset the device.

To spin the motor, go to the Run tab, keep all of the default settings, and press Run Motor. The setpoint is 0 by default, meaning that the motor is being commanded to idle (0% power). When you press Run you should see the LED go from slow blinking to solid, indicating that the motor is idling.

Slowly ramp the setpoint slider up. The motor should start to spin, and you should see a green blink pattern proportional to the speed you have set for the motor. Slowly ramp the slider down. The motor should spin in reverse, and you should see a red blink pattern proportional to the speed you have set for the motor.

If you are unable to spin the motor, visit our .

1. Verify you have completely assembled your MAXSwerve or EasySwerve Module and have the Steering Motor’s SPARK Flex or SPARK MAX connected to the Module's Through Bore Encoder

2. Install and open the latest version of the REV Hardware Client

3. Connect the Steering Motor’s SPARK Motor Controller directly to your computer via the included USB-C to USB-A cable

4. Select the Steering SPARK from the list of Connected Devices and navigate to the Update Tab to verify your Firmware is up to date.

5. Ensure the Steering SPARK is still selected, and then navigate to Absolute Encoder under the Utilities Tab.
6. Then, follow the steps below for the Swerve Module that you are calibrating to ensure that the zero position is set correctly.

Device is not visible

If you don't see all of the devices that you expect to see, follow these steps:

• Make sure that you are connected to the Internet, so that Windows can download the necessary drivers

• Disconnect the device from the computer and then reconnect it

Mac Users and Recovery Mode

If you plan on using RHC2 on a macOS machine, please note that recovery mode devices will only show up on mac if the app is copied into /Applications.

SPARK MAX Motor Controller

• Make sure that the SPARK MAX is not being used by another application, such as the REV SPARK MAX Client

• Unplug the SPARK MAX from the computer and plug it back in

To use your device with RHC2, you must have 2026 firmware (v26.x.x). Devices with 2025 firmware or lower must be updated to 2026 via . SPARKs can be updated via CAN with RHC2 if the bridge device (the device connected to USB) is updated to firmware 2026.

Hardware Tab

The Hardware Tab is where supported hardware devices are managed in the REV Hardware Client. When opening the REV Hardware Client, the Hardware Tab is displayed.

No Hardware Detected

1. Scan for Devices - When supported REV hardware is connected to a Windows or Mac PC the Client will auto scan for new devices.

2. Report an Issue - If you're experiencing technical difficulties with the REV Hardware Client or a related REV device, click this button to send a diagnostic report directly to support staff.

3. Dark Mode - Click to switch the REV Hardware Client to a native dark mode.

4. Navigation - Four tabs are at the top of the REV Hardware Client, allowing you to navigate the different features.

Connecting supported hardware to a Windows PC with the REV Hardware Client running will automatically scan and add the devices to the Hardware Tab.

1. Supported Hardware - Each type of supported hardware will appear. Clicking on the Hardware will bring up each unit's Device Menu.

Selecting a Device will bring up that device's menu. Below is a screenshot of the Power Distribution Hub's Summary Menu.

1. Device Menu Tabs - Swap between the Summary and Update pages here.

2. Firmware - Displays the current software version installed on the device.

3. General Stats - Useful electrical information corresponding to the selected device.

4. Faults and Warnings - If your selected device has any faults or warnings, they can be seen here and can be cleared.

1. Device Menu Tabs - Swap between the Summary and Update pages here.

2. Firmware Version - Clicking the dropdown tool allows you to select the previous or current software versions.

3. Release Notes - Describes what improvements, changes or bug fixes the selected firmware version contains.

4. Download and Install - Under each update type are buttons to download and install that update.

1. Signals - Where you can select different signals for REV devices.

2. Start & Restart Graph - Start initiates recording of telemetry.

3. Signal Key and Scale Adjustment - Signals you choose to monitor will be shown here.

4. Run Single or Multiple Motors - Click the single or double play button to run one or multiple motors for testing.

The Downloads Tab is where downloaded software files are managed. The latest software updates are able to be downloaded without a hardware device connected to the REV Hardware Client.

1. Software Channels - If you acquire a channel code to test beta software, simply input the code and press the plus to have it available.

2. Downloaded Update Files - This section allows for each version of software already downloaded to be viewed, release notes checked, and deleting the files from the local machine.

3. Available Update Files - This section displays the latest version of software to download, release notes for that software, and a button to initiate the download.

The About Tab is where the REV Hardware Client is managed. Here, updates for the REV Hardware Client are checked, downloaded, and installed.

1. Check for Updates - This section displays the current version of the REV Hardware Client and allows for checking for software updates to the REV Hardware Client.

2. Changelog - Lists all significant changes, enhancements, bug fixes, and new features made to REV Hardware Client 2 so far.

3. Supported Devices - This section lists all of the currently supported devices for the version of the REV Hardware Client installed on the user's device.

Version 1.4.2

• Adds a download location prompt for download actions from Control Hub's Robot Controller Console

• Improves recovery of wireless Control Hub connections after a Wi-Fi drop

Version 1.4.1

• Adds a prompt on startup when an update is available, with the option to update now, on exit, or ignore it

• Adds a prompt on startup showing the changelog after the app has been updated

• Adds visualizer for absolute encoder utility

• Adds inversion configuration to A301

• Adds support for opening the update manager directly from a device's update tab to enable updating multiple devices of the same type

• Uses Control Hub's friendly name in device list

• Improves general experience with the FTC Log Viewer

• Updates the supported devices list on the About page to reflect all currently supported devices

• Fixes UI crash on Systemcore

• Fixes Robot Controller Console not working as expected for Control Hubs connected over USB

• Fixes Expansion Hub firmware version not showing up for Control Hub devices

• Fixes Control Hub menu labels being illegible in light mode

• Fixes false positive error toast when attempting to run an A301

• Adds controller support for running motors

• Adds auto-fetching latest releases on startup

• Adds toast to show when an action failed due to being in read-only mode

• Adds setpoint presets to A301/SPARK run pages

• Fixes crash on run tab with A301 on versions before prerelease 16

• Adds support for connecting to a remote RHC2 instance (like Systemcore) from a desktop client

• Adds support for installing/updating a Systemcore's RHC2 from the desktop client

• Adds ability for leader to release control and read only-clients to claim control

• Adds a prompt for Windows users to install DFU drivers if none are found

• Adds support for new A301 CAN specification introduced in firmware version 27.0.0-prerelease.15

• Adds the ability to specify a speed for position control in A301's run utility

• Adds a toggle on the Motioncore card to override the robot program to run motors without a driver station

• Adds gearbox and motor health status cards for A301

• Adds support for REV FTC devices (Control Hub, Expansion Hub, Driver Hub, Driver Station Phone)

• Adds support for CAN Encoder Adapter

• Adds search bar for signals on Telemetry page

• Adds search bar for SPARK configuration tab

• When connecting to a Control Hub via Wi-Fi, no other computer will be able to see the Control Hub until it is power-cycled. The same laptop can continue to see and use the Control Hub even if it reconnects or RHC2 is reopened.

• Adds missing applied output signal for A301

• Adds indicator to navigation bar to show whether you are in read-only mode

• Improves startup time

• Improves CPU and memory utilization during runtime

• Adds support for A301

• Adds support for Linux Arm64

• Adds support for multiple separate CAN buses

• Adds support for updating the bootloader of supported devices

• Linux Arm64 does not currently support devices in DFU recovery mode

• Adds support for configuring new MAXSpline Encoder parameters

• Fixes start/stop button moving when running a SPARK

• Fixes motors not stopping immediately when running multiple motors simultaneously

• Fixes a bug causing devices to appear as remaining in bootloader mode after updating

• Adds button to install DFU drivers on Windows

• Adds warning when trying to run a motor without 12V

• Adds ability to reset SPARK slider to zero by double-clicking on slider handle

• Fixes splash screen not appearing in the foreground

• Adds warning about SPARK devices with an unconfigured CAN ID

• Adds button to clear telemetry signals

• Adds dialog to move the application into the Applications folder on macOS for improved experience:

  • Fixes devices in recovery mode not appearing on macOS

• Adds warning when trying to run a motor with the roboRIO present on the bus

• Adds error toast for when a SPARK parameter value is rejected

• Adds help dialog when loading devices takes a long time, especially for brand new SPARK MAXes on unsupported factory firmware

• Adds privacy policy

• Adds ability to start and stop multiple selected motors simultaneously

• Fixes high CAN utilization when switching between many SPARK device tabs

• Fixes an issue causing some SPARKs to continue spinning when disabling multiple at once

• Fixes an issue causing SPARK devices to resume spinning after leaving the bus and returning

• Fixes crash when opening on macOS

• Fixes detection of devices on Linux

• Fixes app icon

Initial stable release of REV Hardware Client 2

Sometimes, when updating the firmware on an ION Control System Device, it is possible for the process to be interrupted or for the firmware to be corrupted by a bad download or other type of interruption in data transfer. In this state, the Status LED will be dark or dim and the device will fail to operate. There is a built-in recovery mode that can force your device to accept new firmware even if the controller seems to be bricked and the procedure is outlined below:

Materials Needed

• A small tool, like a straightened paper clip or a SIM card removal tool, to press the Mode Button

• Data-capable USB-C to USB-A cable

• Computer with the installed and updated to the latest version

1. With the Device powered off, press and hold the Mode Button

2. While still holding the Mode Button, connect the Device to the computer using the USB-C cable - the Status LED will not illuminate - this is expected.

3. With the REV Hardware Client 2 running on the computer, wait a few seconds for the audible tone or icon for the device to be recognized, then release the Mode Button - no lights will be present on the device during this stage of the process. This is expected

4. Select the DFU Device Bootloader from the list of Connected Devices within the REV Hardware Client 2 window

The REV Hardware Client 2 (RHC2) 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)

Download the latest version of the REV Hardware Client 2

REV Hardware Client 2 - All Versions

Installation Instructions

• Download the REV Hardware Client 2 Installer

• Run the Installer

• Run the REV Hardware Client 2 from the applications menu or a desktop shortcut

• Automatically detect supported devices when connected via USB

• One-click update of all software on connected devices

• Pre-download software updates without a connected device

• Back up and restore user data from supported devices

• Operating System Options:

  • Windows 11, Windows 10 (version 1709 - October 2017) or newer

  • macOS 15 (Sequoia) or newer

  • Linux: Ubuntu 24.04/Debian 12 or newer

• REV Control Hub (REV-31-1595)

• REV Driver Hub (REV-31-1596)

• REV Expansion Hub (REV-31-1153)

• Android Phones

REV Devices must be running Firmware Versions 26.x.x or newer to be compatible with REV Hardware Client 2. Devices with 2025 firmware and below will need to be updated to 2026 firmware via before use.