Updating and Exploring Your Robot Controller Software

Started in the 2023-2024 season, Tech Tips are segments released in the FIRST Tech Challenge Team E-mail Blast. Sometimes the Tech Tips are included in whole in the email blast, but sometimes there is more content than is reasonable in the email blast so partial content is included in the blast with the rest of the content here.

Updating the Robot Controller App

If you use Android Studio, did you know that you’re not supposed to use the REV Hardware Client to update the Robot Controller (RC) App? Blocks and OnBot Java programs are stored on the Robot Controller (Control Hub or SmartPhone) differently than Android Studio programs, and this has a major effect on how updates can be managed on the device. Read more about this at Updating the Robot Controller (RC) App.

Don’t Update the SDK by Editing the Manifest

This section comes to us from an amalgamation of emailed questions asking about allowed ways to update an FtcRobotController SDK project. An approximate summary of the emailed questions along this topic is as follows:

“Is merely editing the Android Manifest file in the TeamCode directory of the FtcRobotController SDK project an acceptable way of easily updating the SDK?”

Even though it’s not forbidden, that doesn’t mean you should do it - like putting pineapple on pizza (sorry, the door was open, I couldn’t stop myself). Seriously, though, 4 times out of 5 you can likely get away with updating the SDK through editing the Android Manifest to point to the latest version of the SDK libraries. However, that assumes that all the Tech Team does is update the SDK libraries, which is never ever the case. In addition to also updating programming samples, often enough the Tech Team must also update tooling, dependencies, and other build items in addition to the SDK libraries, and simply updating the Android Manifest is going to get you into real trouble (things will appear to work, until they don’t, and you won’t know why). As a corollary, you can choose to simply only put gas in your car and ignore all the other fluids, but eventually you’re going to wish you hadn’t.

The proper way of updating your SDK is to use Git/GitHub to update your robot source each time the SDK software updates. The Tech Team always updates the FtcRobotController in-place (meaning the same repo is always updated each version), so if you’re using Git you can easily pull the changes made upstream and accept the changes within your code. You should never be manually updating files, like the Android Manifest file, because Git can tell you all of the files you need to update and can do that for you. If you use Git or GitHub, we highly recommend reading our guide on ftc-docs for managing your Android Studio project repositories.

For example, check out these changelists. The FtcRobotController v9.0 commit/change is everything that needs to be changed to upgrade from version 8.2 to 9.0 - there are 75 changed files there, which include samples, a core interface module change, gradle dependencies, and in that changelist the Tech Team also rearchitected the asset structure. However, the FtcRobotController v9.0.1 and FtcRobotController v9.1 pull requests only changed a handful of files (mostly samples), and the core changes are in the AndroidManifest.xml and build.dependencies.gradle files. In general our major version releases (where we increase the first number in the version string) are the big ones, and then the dot-releases are almost always fairly small targeted releases. The Tech Team tries very hard not to make big-scale changes to build systems or major dependencies during the season.

In summary, teams should never simply change the Android Manifest, they should be updating the software appropriately - as Voltaire warned, with great “Android Studio” power comes great “GitHub” responsibility.

Android Studio “LadyBug” and the FTC SDK

This is an important message for teams who use Android Studio to program their robots. Teams who use Blocks or OnBot Java are not impacted.

On October 1, 2024 Android Studio released a new version of their software, 2024.2.1 codenamed “LadyBug”, which brought a major user interface change as well as several other changes (bundled software and tooling changes) that affects how Android Studio builds projects. Unfortunately these tooling changes broke the native compatibility with the *FIRST* Tech Challenge Software Development Kit (SDK), most notably with the FtcRobotController project. FIRST Tech Challenge teams who use Android Studio with software projects version 10.1 and older are not able to use Android Studio “LadyBug” without performing additional steps (see System Requirements) to restore compatibility.

Teams do not need to update Android Studio to “LadyBug” to continue building current software, however if they do, a new version of the FtcRobotController project (10.1.1) has been released which is designed to work with Android Studio “LadyBug.” Users will be required to upgrade their Android Studio software minimally to Android Studio 2024.2.1 “LadyBug” in order to use the 10.1.1 version of the SDK and newer. There are no feature updates to SDK 10.1.1, it is merely a compatibility update which updates the build tools used by the SDK - including the underlying Gradle tools and the Android Gradle plugin - and eliminates the need to perform any additional steps to use Android Studio “LadyBug” and newer. It is expected that future updates of the SDK will build upon this update, and will minimally require “LadyBug.” Teams who are using older versions of Android Studio who upgrade to SDK 10.1.1 will receive notifications within Android Studio to update the version of Android Studio, which may require an internet connection to update.

Teams are encouraged to read the Managing an Android Studio Project article on ftc-docs for tips on managing their projects using GitHub and the git version control system. Teams managing software projects outside of GitHub and git may re-download the project, reapply their changes, and copy over their TeamCode folder. Teams who need technical assistance may use the FTC Community Forums to receive technical help and advice.

Reading the Robot Controller Source Code

Have you ever been programming your robot (especially in Blocks and OnBot Java) using FTC SDK APIs and wished you could see the source code under the hood that executes the commands you’re calling? Let’s explore the Extracted-RC GitHub repository. Note that Android Studio users can already view source code within Android Studio!

Several years ago, FIRST Tech Challenge gave permission for the OpenFTC project to extract AAR’s from our SDK releases and publicly post an extracted version of the Robot Controller source code. The Extracted-RC repository has branches that contain source code for each release of the SDK, as far back as SDK 5.2 through SDK 9.0.1. You can look up how setPower() works on a Continuous Rotation Servo, how REV Core Hex motors are defined, how Blocks OpModes are started, and even see the built-in driver for the HuskyLens vision camera.

The Extracted-RC repository will not accept Pull Requests (PR’s) since the repository has no actual development purpose - it is only to allow interested folks the ability to read the source code and see how things are implemented. Only FIRST staff and Tech Team members have access to the development source. Are you interested in joining the FIRST Tech Challenge Tech Team? Let us know by filling out this survey!

Got any questions about updating your robot software? Come start or join the conversation on the FTC Community Forums!