I really like APM and the ArduCopter code seems to be well done. But I am interested in computer vision and want to use a gumstix overo tide to do processing. Since there is so much power in that platform it seems unnecessary to do something like have it talk to the ardupilot mega hardware via I2C and send down mavlink messages (even though this seems the easy route it seems like unnecessary power and payload consumption would be the case). I am interested in porting the ardupilot mega code to run on the gumstix. I have not read the entirety of the code, in fact I have only read a few of the files, I would also need to get a 6dof imu to work with the gumstix (though I am sure this can be done) and to get that imu to talk to the ardupilot software. How compatible is the software with non-intended hardware, can anyone shed some light on this?
Thanks,
Matt
Replies
Hi Matt. I'm currently in the process of designing a quadrotor with a Gumstix Overo on-board (also see here). However I think porting ArduCopter code would be impossible, as the two are completely different environments. You would be able to lift some algorithms I suppose but you'd have to program the software yourself (anyone feel free to correct me!). I intend to use a Pinto-TH expansion board to connect to the IMU (serial) and output PWM signals (note that the Gumstix uses 1.8V logic, you will have to level shift this to use it with ESC's). Have a look at Scott Ellis' website for a great resource on Gumstix i/o.
People have had OpenCV run on the Gumstix, however I do not have details about this. There has even been someone who has accelerated the OpenCV algorithms using the on-board DSP available on some boards.. (You'll find this on google).
Hi Matt,
Not sure if you are aware that there have been people working on UAV/computer vision based on gumstix overo. Just search for pixhawk in the forum. They occasionally also report on their progress here.
Otherwise: about 2 years ago when I first got into the hobby I got myself an overo and put it into my MPX Twinstar, together with a webcam and a wifi connection (both via usb). Planned to sort out the servo control/autopilot/IMU functionality later on. I managed to send webcam pictures downlink but got extreme interference with my 35MHz radio receiver (though this may have been the USB bus I also found at least one more person via google who noticed the same). Also ground shielding did not really help.
Also, what I initially had not thought about, is that the regular RC servos operate on 5V PWM, so one would anyway need some sort of interface board/motor driver for those, in addition to the IMU. This is when I found the ardupilot (the APM was just new I think) and never looked back to the gumstix. Still planning to use it for something though, maybe for the ground station.
Anyway.. I'd suggest you to have a look around. As you say yourself, you can always link the two together via I2C (haven't tried yet myself). Or you have a closer look at what the pixhawk guys are doing.
Have fun, good luck, Andre