Gumstix

[chopsuey]

I am looking at purchasing either of these packages.

http://gumstix.com/store/catalog/product_info.php?products_id=147
http://gumstix.com/store/catalog/product_info.php?products_id=146

I am a little confused though. Will I be able to control servos with the use of the robostix? Will I need to supply additional power to the robostix to power the servos? Will I need any additional hardware? Does anyone own one of these? I would like to hear your experiences. Thanks.

[Vindication]

Yes,

I have one but haven't used it much other than running a couple example programs on it. One was for controlling servos.

You will need to supply power to the robostix and then also to the servos. This works in much the same way as a typical rc reciever. Either plug a reciever battery to one of the servo ports or a Speed Control w/ BEC circuit...

-Vind

[hogar]

Take a look at (http://perso.wanadoo.fr/pascal.bris...ml#pwm_accuracy) and see how they control servos from gumstix. I have done the same and it works fine.
-hogar

[chopsuey]

hogar: That link doesn't seem to be working for me. Are you using a gumstix in your UAV?

[hogar]

Sorry, I try again http://perso.orange.fr/pascal.brisset/chromicro/doc/chromicro.html#pwm_accuracy
I plan to use a gumstix, but I am far from have a working concept.

[chopsuey]

Thanks!

[defy]

Heres my gumstix setup

http://defy.net/balloon/images/nav_computer.jpg

gumstix, robostix, gpsstix, a couple of sensors and mostly my own software. the box is just for portability while testing, I haven't chosen an airframe yet. also using maxstream zbee's for shortish (1mile) range wireless.

So far I'm loving everything about these little boards.

[space_case]

gumstix, robostix, gpsstix, a couple of sensors and mostly my own software. the box is just for portability while testing, I haven't chosen an airframe yet. also using maxstream zbee's for shortish (1mile) range wireless.

So far I'm loving everything about these little boards.

Are you using a passive antenna on the gpsstix? How is your reception?

[defy]

Nope I'm using an active antenna, but a track needs to be disconnected and a resister added between the 3.3v vcc and antennas power pin on the gps module before it will work. Pictures of the hack and a link to more detailed instructions are on my project site at http://defy.net/balloon/

Reception with the active antenna is great.

[space_case]

Yeah, I've seen the mod. I'm debating on whether getting the GPSstix or integrating an OEM module.

Isn't the GPSstix running at 4Hz? How many serial ports did this leave you with? Are you using I2C?

[defy]

Not sure what Hz its running at, the u-blox data sheet for the module should say. It leaves me with 3 usable uarts (they are 3.3v ttl), by default ttyS0 is console, but that can be turned off. and I'm using i2c to connect the gpsstix to the robostix with the i2c-io software so I can read my sensors and control the servos.

The major downside to the gpsstix in this kind of project is all the wasted features. It comes with a sound mic and speaker jack and pinouts for an lcd and touch screen. All pretty useless features for a uav.

[space_case]

I don't understand why they built GPSstix on the AUDIOstix platform. I think I saw 4Hz on the sheet. Thanks for the info.

I have the 400 basix kit, the robostix, and an RF modem. I just need some sort of IMU and GPS. I see you are using the thermopiles. Maybe I should go that route.

[defy]

I think their target market for the gpsstix was people wanting to make their own hand held gps units. They are pretty nice little boards, once a revision comes out and they fix the few flaws the first revision was released with, I'll probably get another and have a go at getting the lcd and touchscreen working.

I only just discovered thermopiles about a month or so ago after browsing this forum, so I ordered a couple. Perfect technology for what I wanted, and I have 4 rotation rate sensing gyros which were given to me so I think I'll try to combine the gyro and thermopile somehow. Maybe use the gyros reading for quick corrections and the thermopile for leveling out...not entirely sure yet...I need to choose an airframe and get it all in the air for testing :D

[karthik_tunga]

hey!

I am using GPSstix along with gumstix. I have a few doubts .

1> does the GPS module continuously fetch the location and other parameters ?? or can it be called only when needed and then stopped ????
2> If the GPS module continuously fetches the data ..how can we know when the " /dev/ttyS2 " file is updated by the module ??
3> how long does the module take to find its position ? meaning how long does the module take to fetch the data ??

I hope I have made my doubts clear ... I am design a system wherein i don't need the GPS data all the time ..only when required ...( I am placing the gumstix on a moving object.)

Thank you
Karthik Tunga