I was trying to use the DroneKit-Python API to control the movement of a drone. I've been reading what it's in that link, but I can't find what I need. I want to be able to run the code with the dron indoors (and of course outdoors), so I can't rely in the GPS. I've tried to eliminate that part and use only the send_ned_velocity() method (without the propeller). But I couldn't hear a significant change in the movement of the engines.
The only way I can think of is using the channel_override, but it doesn't seem to be the better choice. Can anyone help me?
Thank you in advance.
send_ned_velocity() will only work if you are in guided mode. With Arducopter 3.3, you can only be in guided mode if you have a gps lock. So you aren't going to be able to use this command indoors.
You'll have to wait for 3.4 to be released, then guided mode will be supported without gps. But instead of gps, you will need an optical flow module and a rangefinder installed and configured.
Related
I am very new at this and trying to get an understanding of this. I have read a lot on the DroneKit-Python site trying to figure out how exactly am I able to communicate with it.
Drone I am currently using is Iris+
I have looked more and there are software that already provide this, but I want to be able to control it plus more.
I want to set waypoints, tell it to then fly give the way points and keep going to them. Also, to be able to arm itself, which is in the example, and override the safety mechanism.
Here is the basic of what I am trying to use it for. Have it fly up at a certain time. Go to the waypoints 1,2,3,1,etc.. Then after X amount of time or on low battery go back to launch point and land.
I have found plenty of code that provides what i need to do, though I don't know if it will work and more importantly I don't even know how to start programming for this. Maybe I have the wrong approach in doing this?
I kind of want this to be a light API, so that in the future I can make a simple UI on my phone and insert some coordinates to give it ways points and that is it. I know there is software out there already that does it, but I want to remove the need for touching the drone. I want it to start and end autonomously.
If anyone could help provide some info that much would be greatly appreciated.
Assuming you have no companion computer (Iris+ does not by default), you are OK with running a ground station app (you won't be out of range to send commands to "end mission on time expiry") and that driving the behaviour from your phone is important, I would be looking at DroneKit Android.
Some notes:
You're going to have to touch the drone at some point to attach the
batteries.
You can arm the device from dronekit
You can override the safety mechanism from a script. I hope you have
a lot of money to pay for the new drones you're going to have to buy when they crash and all the litigation from damaged people and property (in other words "don't do it".
The default behaviour is to return the device to launch (RTL) on low battery. This is convigurable
Setting a time is more "problematic". You can have a timer in a script that then sends return-to-launch but the script needs to be connected to the UAV. This means that either you have to be running in a connected ground station (which might potentially be out of range) or on a companion computer.
Iris+ does not have a companion computer. You have to install one or connect from a Ground Control Station.
DroneKit-Python runs on Linux, MacOSX or Windows. You can't just run it on an ordinary phone, though you could find some other mechanism to send messages/scripts to it running on a companion Computer.
DroneKit Android runs on Android. We do have a planned iOS version too. In theory these could run on a companion computer, but in practice currently these are only used as ground stations.
I asked this question in the Raspberry PI section, so please forgive me for posting this here again. Its just there doesn't seem to be as active as this section of the forum. So, onto my question...
I have an idea and I'm working on it right now. I just wanted to see what the community's thought was on using a screensaver as digital signage. Every tutorial I've read shows someone using chromium in kiosk mode, and while that's fine and works well for some uses, it doesn't work for what I need. I have successfully completed a chromium kiosk, and it was cool. But the signage that I need to create now, has to work without internet. I've thought about installing LAMP locally on the PI, and still using chromium. I still may have to if this idea doesn't pan out. All I need from the signage is a Title Message in the top center, and a message body underneath it, with roughly 300-400 character limit. My idea is to write a screensaver module, in C, that will work with a screensaver such as xscreensaver. The module would need to be able to load messages from a directory on the pi. Then for my clients to update their signage text, I would write a simple client that sent commands as well as the text via SSH to the pi. I want to know what other people think about this. Is it a good idea? Bad idea? Should I "waste" my time doing something like this?
Thanks in advance.
I am already using a rPi as digital signage, just over a year. I am using two different setups:
version 1 uses Raspian loading xdesktop and qiv image viewer to cycle images stored on the Pi itself, synchronized with a remote server. The problem I found was power and SD stability, when the power fails, which it will do no matter what, just when... The Sd card can become corrupt due to all the writing that Raspian does all the time. Certainly does not really need to write to SD.
version 2 uses a RO-filesystem and a command line image tool. Uses the same process to show images from local, and sync with server. But power fail causes no ill effects.
I am not using screensaver to display images, that seemed redundant to me, and unnecessary to wait for the SS to start just to display the images.
Some of the images are created using imagemagik, which is nicely dynamic where needed.
Here is the situation. The company I work for builds this piece of software in c that can make a Windows computer act a bit like a TV. Essentially, our piece of software is meant to be played full screen and content is displayed from the internet without the user having to ever touch the computer again.
The problem is that once in a while, the system brings up pop-ups like "Your Windows system is ready for an upgrade." or "Please renew your Norton subscription" etc. which the user has to periodically and manually remove.
Is there a way to display content full screen without being bothered by those warnings?
Yah, whether or not the development community agrees, Microsoft has several standards for when and why it might be acceptable to have exclusive use of the monitor.
The most official strategy is to use DirectX in exclusive mode. This is what games do, what windows media player does in full screen video with hardware acceleration enabled, etc... If your application is multimedia intensive (as suggested by TV like functionality), you should probably be using DirectX too. Besides giving you the exclusive display access it will also increase your applications performance while lowering the CPU load (as it will overload graphics work to the video card when possible).
If DirectX is not an option, there are a great number of hacks available that seem to all behave differently between various generations of windows operating systems. So you might have to be prepared to implement several techniques to cover each OS you plan to support.
One technique is to set your application as the currently running screensaver. A screensaver if really just an EXE renamed to SCR with certain command line switches it should support. But you can write your own application to be such a screensaver and a little launcher stub that sets it as the screensaver and launches it. Upon exit the application should return the original screensaver settings (perhaps the launcher waits for the process to exit so that it returns the settings in both graceful exits and any unplanned process terminations ie: app crash). I'm not sure if this behavior is consistent across platforms though, you'll have to test it.
Preventing other applications from creating window handles is truly a hack in my opinion and pretty bad one that I wouldn't appreciate as a customer of such software.
A constant BringWindowToTop() call to keep you in front is better (it doesn't break other software) but still a little hack-ish.
Catch window creation messages with a global hook. This way you can close or hide unwanted windows before they become visible.
EDIT: If you definitely want to avoid hooks, then you can call a function periodically, which puts your window to the top of the z-stack.
You could disable system updates http://support.microsoft.com/kb/901037 and remove the norton malware.
You could also connect a second screen so that the bubbles appear in the the first monitor.
Or you rewrite it for linux or windows ce.
One final option is to install software that reconfigures your os into a kiosk http://shop.inteset.com/Products/9-securelockdown.aspx
If you don't need keyboard or mouse input, how about running your application as a screensaver?
A lot of thoses messages are trigged/managed by Windows Explorer.
Just replace it with your dummy c#/winform.
By changing the registry value
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
"Shell"="Explorer.exe"
You can specify virtually any exe as an alternative to explorer.exe
That's the way all windows based (embedded) system (ATM & co) do.
There's still few adjustment (disable services you dont need / dr watson & others), and of course, you'll want to keep a "restart explorer.exe" backdoor.
But that's a good start
I want to make project for my final year in college.
So someone suggested me to make Remote Desktop in C.
Now I know basic socket functions for windows in C i.e. I know how to make
echo server in C.
But I don't know what to do next. I searched on internet but couldn't find
something informative.
Could someone suggest me how to approach from this point..any tutorial...or any source ?
I think this is do-able. For a college project, you don't need to have something as complex and as full-featured as VNC. Even demonstrating simple keyboard and mouse control and screen feedback would be enough, in my opinion, and that's well within reach.
If you're doing everything from scratch and using Win32, you can get the remote screen using the regular "printscreen" example all around the internet.
http://www.codeproject.com/KB/cpp/Screen_Capture__Win32_.aspx has it, for one. You can then compress the image with a third-party library, or just send it raw; this wouldn't be very efficient but it would still be a viable demonstration.
Apart from capturing the screen data remotely and showing it in the local window, you'll need to listen for local window messages for mouse and keyboard events, send them to the remote host, and then play them back. http://msdn.microsoft.com/en-us/library/ms646310%28VS.85%29.aspx will probably do that for you.
Check tightvnc TightVNC is a free remote control software package. The source code is also available.
For sending the image of the screen I would probably use rtp. The JRTPLIB is really handy for that.
And yes, as KevinDTimm says, an echo server is the very easiest part.
KevinDTimm may well be right, writing an RDP client would a fairly significant undertaking. To give you some idea, the current spec, available at the top of this page, is 419 pages long and includes references to several additional documents for specific aspects of RDP like Audio Redirection and Clipboards.
i am developing a video player i silverlight
i wanna something to prevent recording or screen capturing
i thought about hacking the windows APIs and stop my program from running if there was any of those capturing software asking the user to close it first but i donno how to do this
is there another solution ??!!!!
It's simple not possible. If you try it, you're only going to annoy people.
Even 'hacking the windows API' would not work, since the OS itself could be run inside a VM.
I hate to be a downer, but task is impossible to fully accomplish.
If you were somehow able to hook the keyboard (from a silverlight app no-less) I would certainly hope that whatever AV the user is running would throw up some red flags.
Also what if the user doesn't use the standard (alt)+prtscr? A third-party tool might use a different key-combo. Also, I've written a screen-grabber with the GDI+ API, and there's no way to disable something that low-level.
What about attached capture-cards? What if your app is running in a VM or over remote-desktop?
If you are that deeply concerned about protection your HD content, watermark it, or make the user pay for it first.
All-in-all, as soon as your content's data enters your user's computer, they can duplicate it.
You could go about using a key hook system, stopping the user pressing the print screen key on the keyboard, that would be a start. There aren't many systems which stop users from print screening video specifically. You might want to try just watermarking your video instead? At least then people know that the video was originally sourced from you.
The solution is not to allow your application to run on a computer, but instead target a device such as a phone. Computers will always allow some kind of screen capture and video capture but this is much harder and less likely to be tackled if you restrict to only playing on certain devices.
How badly do you need this? There are many ways to defeat screen capture protection: for instance, aiming a video recorder at the computer screen (or looping output to a TV with a capture card, etc. etc. etc.)
Go for a commercial solution if you really really need this: don't have any experience with those myself, however.