Drones and ROVs and Arduinos

A journey building drones and ROVs and other open hardware and Arduino based stuff

Testing the OpenROV cape

Last week I received a prototype version of the OpenROV Cape (previously known as ArduSwimmer) and over the last few days I tried assembling as much as possible to finally be able to test the Cockpit software on the real hardware and not only on my Mac. This also because this evening we have a call with all the developers of OpenROV to see if we are good to go releasing the first version of the software that will ship with the kits.

Setting up the cape

The prototype cape came without headers or connectors so my first step was installing 4 sets of 90° headers for the 3 ESCs and the tilt servo. But ESCs and servos are not the only things that have to connected to the cape: also the 2 AUX output and the power supply have to connected to the cape. At the moment I didn’t have any connector available so I soldered the cable directly on the board itself, but I think of buying 3 JST 2 pins connectors to make it possible to switch devices and power connectors (battery, or bench supply).

Cape and LEDs


I soldered the 2 high power LEDs to the same AUX1 so that I keep AUX2 free for any other payload, and then directly to wires so that I can power the cape with 2 alligator clips, but I’ll replace both with the JST connectors.

Loading updated cockpit and arduino code

After I got the electrical part working, I got the latest code (I had already copied the official image on the SD). It was super-easy: all that was need logging on the beaglebone via ssh and launch an update command which goes online and pull all the latest changes from the official github repository. Just remember that “it goes online” so your board has to be connected to the internet, and not just to your computer with the ad-hoc connection.

On the other hand I couldn’t get the cape updated with the latest arduino code via the UI. It kept on failing and at the end I decided to remove the chip from the cape, put it on my UNO and load the code from my computer. No idea why it failed since the chip has the right bootloader on it.

Plugging in ESCs and Servo

Once I finally had the arduino code on the cape I was able to control brightness and tilt servo via the Cockpit’s web UI. I had some problems with the brushless motor, which was not running at all. Thanks to the latest diagnostic screen I tried manually controlling the speed and at the end I just ended up calibrating the ESC again. And after that everything went smoothly.

The complete testing setup

Testing everything

As final step of the day, I decided to do a complete system test, both with the keyboard and the gamepad. Apart from the beaglebone shutting down sometimes when there is too much current drained from the motors the cockpit software worked great. Here is a short video that shows the test:

As you see, also the tilt servo acts a bit weird at the end of the video: I think it’s the gamepad sending some noise that needs to be filtered somehow, but apart from this, everything looks pretty for tagging the code for the release. Other improvements will be done later, and hopefully everyone will update the software as first thing after they receive the kits.



3 comments on “Testing the OpenROV cape

  1. Tom
    December 5, 2012

    Nice video and examples of your work! Thanks for your contribution to the OpenROV project, I am hungry to start building one of them!

  2. Pingback: A better OpenROV cape wiring « Drones and ROVs and Arduinos

  3. Pingback: Testing Arducopter using a bench power supply « Drones and ROVs and Arduinos

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This entry was posted on December 2, 2012 by in OpenROV and tagged , , , , .
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