Embedded Development

With looking at the last post, I'm detailing out 4 main modules. The largest of the modules is the Drone Software module. This module is the executable that actually runs on the drone itself. This post will detail the architecture of the drone executable module; along with how to get started writing it. First, let's talk about how to get navigator libraries to work in Android Studio. Remember that we're linking in a dependent pre-built library. I suggest using CMake as it has strong integration within Android Studio and is well supported. To use CMake, create the project as detailed here . Now, edit the CMakeLists.txt file and add the library dependency like so: include_directories( ${CMAKE_CURRENT_SOURCE_DIR}/snav/1.2.31_8/include ) add_executable( drone-controller ${SourceList} ) add_library( libsnav-arm SHARED IMPORTED ) set_target_properties( libsnav-arm PROPERTIES IMPORTED_LOCATION ${CMAKE_CURRENT...

Finally we're at the point in our opus VR drone project that we need to look at the software. If you're following along, I have the Hardware drone built, using Snapdragon flight . To review, we have knowledge of how to create a project in Android Studio that can target Snapdragon Flight for deployment. We know how to utilize the Daydream controller to build an arm model . We also know how to setup a VR project in Android Studio . Finally, we know how to communicate with the Snapdragon flight controller. So, if we put it all together, we only need to figure out how to program the controller aspect of the Flight. Thankfully there's rich support available for Flight that allows us to have full C-API control over both the ESC and the controller board. It is provided through the navigator api library . Now let's talk about the overall design. I envision four main modules: VR Controller App interfaces with the user gets positional updates and issues commands de...

In working with the Drone project, I ran into an issue. It turns out to be really hard to control the drone while transitioning from/to VR. That is to say, when the drone is in the air, flying it in VR is really comfortable and easy. However, getting it to the air and then transitioning to VR mode is a challenge. Also, what happens when the VR mode allows the drone to do something that would allow it to crash. There's two potential solutions to this problem. 1.) I could advocate for having a buddy control the drone and keep it in stable flight allowing manual switch over for when ready for VR control, or 2.) I could advocate for writing some AI to allow the drone to control itself. I'm Opting for #2 for a few reasons, first I'd rather be able to fly the drone whenever I wish whether a buddy is available or not. Also I'd like to avoid creating multiple control capabilities and then require a certain skill level to control my drone. Finally, I'm a programmer, ...

If you're with me so far, in our Snapdragon Flight VR build, you might have noticed that the connectors that come with the motors do not match the connectors that come with the Snapdragon ESC. This means we need to replace the connectors so electrons can flow and power the motors. Remembering that the whole point of this is to get electrons to flow will make the concept easier. Copper is a conductive material, that's what wires are made up of. Solder is a metal material that is highly conductive with a low melting point and solidifies fast. So the idea is we want to use the molten solder to join the wires to the new connector. I personally favor damaging a cheap motor to damaging an expensive ESC, so I opt for doing the work on the motor connections themselves and highly recommend this path. While the minimum you'll need is 4 connectors, I am really good at making mistakes, so I wound up getting 10. The first step, is to cur the old connector off. Grab a pair of w...

In order to have a VR Drone, we must start building a real physical Drone. Snapdragon Flight offers a great light weight powerful platform we can do a lot with. While most home built Drones are built with very custom specs; I felt it necessary to make this very approachable by ensuring the Drone is built exactly as the specs outline. Our's looks slightly different, but hey Drone time! Let's start with the parts the Drone needs: Allen Wrench Hex Key Set Dynamite 5 pc Metric Nut Driver Assortment Generic M2.5 Nylon Hex M-F Spacer/Screw/Nut Assorted Kit Loctite Heavy Duty Threadlocker 2x clock wise motors 2x counter clock wise motors ac converter for battery charger battery charger Battery ESC (to control the 4 props) Frame Kit gps antenna 4 x DF3-3P-2DSA connector Wifi antenna Grey props: x2 Red props: x2 Before jumping straight into working with the hardware, a small house keeping task must be preformed. There's a small problem, If you have big ...

In order to connect to a USB Serial connection as is the case in connecting to Snapdragon Flight , there's slightly different ways for each host operating system. I broke this up to a separate blog post to provide easy reference for any other project. I'd note that these instructions work equally well on Intel's Edison boards which also require USB Serial connections. If you're trying to connect from windows, here's some steps for you: Run putty Now configure Putty as follows: Click Serial under Connection Type In the Serial line field, enter the COM# for your board, such as COM12. NB: If you did not identify your COM# when setting up your board, navigate to the Device Manager and check for an entry called USB Serial Port (not Intel Edison Virtual Com Port). The COM# is displayed next to the USB Serial Port entry, as highlighted below. Give the Speed field a baud rate that seems appropriate: 115200 Your configuration screen should look like this: C...

It's time for some fun. An awesome use case in how to use quaternions to achieve portable results. If you aren't familiar with quaternions, please feel free to review them in my previous article. If that's confusing, it's no problem, you can use the code from below, but it might be a bit tough to understand without the prerequisite math knowledge. So let's write the inspiration: Notice that controller? One here too! In the world of mobile VR, the two main systems, Google's Daydream and Oculus' mobile GearVR, are both now shipping with a controller that is used much like a laser pointer in the virtual world. While both Google and Oculus provide an SDK for working with the controller, much of what it takes to work with it is missing in any form of documentation. Thus most apps rely upon other people's controller implementation and create a project wide dependency (Unity, Unreal) just for one very small aspect of the application. Also, my project...