I recently finished writing the first edition of OpenDroneMap: The Missing Guide. I thought I’d write a blog post about the overall experience in the hope that it will be useful to other want-to-be writers. First of all, if you are a software developer and you are thinking of writing a book about a project you’re involved with, don’t do it for the money; the amount of work required to write a book is huge compared to the monetary returns. […]
Docker can take a toll on your disk space. Fortunately you don’t have to keep the files in /var/lib/docker and on certain cloud providers like Digital Ocean it’s cheaper to attach a new block volume than to upgrade a droplet to get more disk space. After you’ve decided on a location, simply do: Change /lib/systemd/system/docker.service: Then: When you’ve verified things are working, remove the old docker directory.
Installing ROS on Arch is a pain in the rear. The fact that Arch is a rolling release distro makes it difficult to compile most of ROS dependencies. Even if you eventually manage to compile everything, you will find yourself running into all sorts of trouble compiling third party libraries, fixing problems between Python 3 and Python 2 and don’t even ask what happens when you do a system update. Save yourself the trouble and use docker. You will be up […]
Today I bricked this little drone by flashing the wrong firmware (whoops)! Turns out that the correct board to choose when flashing a new firmware is “OMNIBUS“. Oh well, good opportunity to learn how to take this thing apart. Unplug the camera plug from the side by gently pulling the cable out. Optionally also remove the props (I didn’t) to have more maneuvering space later on. 2. Set the drone on its back, and remove the 8 screws circled below […]
It is indeed possible to mount a GoPro on a Syma X5C. It is however, not ideal, since the Syma X5C is a toy and its payload capacity is limited. But if you’re like me and you like to push the limits of your hardware, this is not going to stop you from trying, is it? 🙂 I used a GoPro Hero3+, but the process should be similar for other models. 1. Reduce the Weight The Syma can’t pull much weight. […]
You can share a terminal session using your Kindle, which means you can use it as an external monitor for text-only applications. You won’t be able to do much web browsing or design work beside ASCII art, but if you’re a coder or a sysadmin, I’m sure this is not really going to bother you. Here’s a brief list of steps required to get this hack working. Jailbreak your Kindle. Install a Terminal application on it so that you can open […]
If you are a T-Mobile customer and tether your internet connection from your phone, you might have encountered this annoying screen: Now this is a ridiculous effort by T-Mobile to charge you twice for using the data plan that you already paid for. I call it a ridiculous effort because they have no sure way of detecting whether an internet request comes from your phone or from a device connected to it, and this is clearly a way to milk […]
So you have setup your own mail server on Digital Ocean. Everything works great, but for some reason all of your outgoing mail to Gmail’s addresses ends up in the Spam folder. What to do? 1. Check your SPF record SPF is a validation system to detect spoofing and needs to be setup in your DNS records. Fire up the DNS console of your droplet and make sure that you have it setup properly by adding a “TXT” record with the following […]
The hardest debug situation of my life just ended. Celebrate! I was trying to make a USB audio adapter to work on an embedded device running OpenWRT, but Linux wasn’t recognizing the USB device. The device turned on, but wasn’t getting mapped to /dev. So I think, ok, I probably forgot the modules. I Installed the modules. Still no luck. Maybe I chose the wrong modules? I started trying different permutations of modules (with each try taking half an hour […]
A few days ago I found that there is no way to print on Sublime Text 2. I was a little disappointed with this discovery, printing is such a basic feature that even Notepad offers. Why doesn’t Sublime Text 2 include it? Ok, besides saving trees, I hate to print stuff on paper myself, but sometimes you will be asked to print your code, either by a professor or someone else wanting to review your code. In the meanwhile I […]