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Re: Lost Crazyflie in high grass

Posted: Sun Jun 02, 2013 5:17 pm
by Surrender
This will be a great feature because the CF is so small that it's hard to find outside.

This "come find me mode" should be activated if the connection is lost. The motors should shutdown when the voltage reaches ~3050mV to prevent a cut-off. After the shutdown the voltage is raising, now the PWM should be activated to make the search mode running. Would be also a nice idea to make music during the fly (changing PWM frequency for sound and PWM duty cycle for motor speed).

Concrete:
- Motor shutdown @ ~3050mV (@3000mV -> cut-off)
- Start the soundmaking PWM (one frequency beep for finding, EDIT: Loudest sound @res. freq.)

Interesting article about making sound with dc motors: http://letsmakerobots.com/node/18211
Some soundgenerating methods: http://www.uchobby.com/index.php/2007/1 ... nd-part-1/

Re: Lost Crazyflie in high grass

Posted: Sun Jun 16, 2013 10:37 am
by zak
Just had something similar happen to me - I've been flying outside recently and have got quite good at controlling the flie. Unfortunately I got overconfident and lost it this afternoon over someone's house (at least, that's where I think it went down)! After having a look through their front garden and scanning with my laptop (I even found a 5 dBi antenna at home to try out), nothing has shown up and at this point I've given it up for lost.

Consider this a +1 for the 'come find me' mode! It's a testament to how much fun I've had with it that I'm considering replacing my flie when the next batch of orders becomes available...

Re: Lost Crazyflie in high grass

Posted: Sun Jun 16, 2013 11:20 am
by foosel
Let's play some Jeopardy, shall we? "Crazy ideas for 400 please!" - "This mod makes it fly sluggish but you can find it again in high grass" - "What is a loc8tor tag attached to a Nano Quadrocopter?"

Image

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Ok, this isn't really practicable ;) Just had one of those tags lying around (got myself a loc8tor set for my AR.Drone, since I nearly managed to lose that in high grass some days ago) and though I'd give it a try. It flies. It feels very very sluggish, and it needs way more power than usual to lift, but it flies ;)

Re: Lost Crazyflie in high grass

Posted: Sun Jun 16, 2013 1:49 pm
by zak
foosel wrote:Let's play some Jeopardy, shall we? "Crazy ideas for 400 please!" - "This mod makes it fly sluggish but you can find it again in high grass" - "What is a loc8tor tag attached to a Nano Quadrocopter?"
Given my current Crazyflie-less state, that seems like a pretty brilliant idea to me! About an hour after I've lost it, there has of course been a storm - even if I do end up finding it (unlikely enough), I'll be very impressed if it's still working :)

Re: Lost Crazyflie in high grass

Posted: Sun Jun 16, 2013 2:07 pm
by foosel
I just opened that tag up and took it apart (as far as reversibly possible). It's powered by two 1.5V coin cells (SG10, 72mAh each, according to the product specs the tag should run 2-9months on that). Shaving the weight of those coin cells plus the plastic case off (all in all 4.06g) we come out at a pure tag-weight of ~1.4g. If it is possible to power one of those things off the CF's 3.3V (I don't dare to try it right now ;)) it might actually be feasible to use one of those things as an onboard locator tag, mounted somewhere below the CF or something like that.

Re: Lost Crazyflie in high grass

Posted: Sun Jun 16, 2013 3:00 pm
by tobias
I'll be very impressed if it's still working
I lost one of our prototypes like that and it was lost for two days. First in rain and then below zero degrees Celsius. When I found it a removed the battery, let it dry for 24 hours, cleaned it with alcohol, turned it on and it worked :).

I'm getting the feeling we should prioritize the work on the "find me mode".