what components to use

hi,
i am new to arduinos
i have a project at my university whare i am supposed to make a bomb drop mechanism for an aircraft and i have no idea how to do that,
browsing through the internet i found arduinos and thought of this as the best option.
so if anyone could help me what components should i buy and make my project, it would really be helpful
i need to make a wireless circuit to drop a 25gm package

You're not a terrorist, are you? :D

We need more parameters about the project to be able to reply intelligently. Is this a radio-control aircraft?

ok... so for the project...its going to be a glider...which will be designed by other group members... and i am responsible for the package drop mechanism...which has to be wireless... the model will be thrown inside a room and it has to cover approximately 8 meters before dropping the package and then land safely... the model should not weigh more than 500 gm or less than 400 gm... as of now we are considering balsa wood for the making the model... and i am clue less about what should i be doing...

Use like an arduino nano to control a solenoid that releases a latch on package
There are plent of ways to transmit wirelessly and trigger the arduino,
They could probably use the an arduino to control the whole thing

i found a 315 and 433 MHz Superregenerati?on wireless Kit for Arduino MCU on ebay can any be used for my project...for the wireless transmission with arduino nano ???

Yes, you are going to have to make a controller of some sort tho, a way to trigger it
I haven’t used thos kind of wireless before but you could probably figure out something simple if its just one thing

thanks for the reply...i am in need of good help at the moment...

well i only have to control a servo with it... and as for the controller...can it not be done with the laptop...or something...

Im not sure, you would need perhaps a type of wireless serial atleast like xbee and parse the serial into the command

I think everthing worth to try.

You need short range wireless communication. A standard sized "shield" may be heavy for your model, so probably an BT xbee would be the lightest alternative. Normally easy to control from a laptop (either built in or very small USB dongle)

You want light weight?

Instead of servo perhaps use memory wire to flip a latch or pull string on a bow knot like untie a shoe.

Wireless can be IR same as TV remote. That would let you use an AT chip with little else instead of needing a whole board. Wire up a socket for the chip with power and light detector then pop the chip in, you don't even need the weight of a board. Just make sure that room light won't trigger the drop or block the signal, but does your TV have such problems? No. Well you do this for lesson and credit.

Here is how-to program ATTiny45 or 85 chip to do the job:

Full instructions and download of needed software: http://hlt.media.mit.edu/?p=1229

See how easy on youtube: http://www.youtube.com/watch?v=30rPt802n1k&feature=list_related&playnext=1&list=SP23C82C496271F7B9

They are 8-pin small with internal clock, use less power, need less battery. Maybe you could get away with a PC backup capacitor (farad or more, lot of juice) and a resistor instead of battery if only needed for short flight.

I think you could use the chip in your Arduino though you probably don't want to.

So weight is a major concern. You did not state if the dropping mechanism has to be reusable. If dropping the bomb is allowed to destroy the mechanism I would suspend the bomb with some plastic filament and use some heating element to melt through the filament.

The Arduino is overkill for this kind of project. You need just a IR or RC receiver that can output a signal to drive a transistor. No fancy microcontroller solution required. That is I would use something like this http://www.parallax.com/Portals/0/Downloads/docs/prod/audiovis/PNA4601M.pdf and just detect the presence of the carrier signal. If you have to use a servo, just amplify the (carrier) signal and rectify the signal before you put it to the servo.

Also your rules do not state what exactly is the meaning of "wireless". So other options might be timer based, sound / microphone based, light based (trigger by a bright flash or a laser).

If you insist on overkill though go for something like the yellowjacket: http://ruggedcircuits.com/html/yellowjacket.html

One more thought: why not just scavenge the remote control + receiver from a cheap toy airplane? E.g. something like this http://www.amazon.com/Syma-S107-S107G-Helicopter-Blue/dp/B003TVTPS0/ref=sr_1_14?ie=UTF8&qid=1319556487&sr=8-14.

Engineering lesson #1: clarify build vs. buy first ;)

[quote author=Udo Klein link=topic=76327.msg579388#msg579388 date=1319556569] One more thought: why not just scavenge the remote control + receiver from a cheap toy airplane? E.g. something like this http://www.amazon.com/Syma-S107-S107G-Helicopter-Blue/dp/B003TVTPS0/ref=sr_1_14?ie=UTF8&qid=1319556487&sr=8-14.

Engineering lesson #1: clarify build vs. buy first ;) [/quote]

Ohhhhh, I really like that one! It's probably got an actuator and power and has already been debugged!

3 channels --> 3 actuators. To be precise 3 motors.

And it is already optimized for weight.

thanks for all the replies... there are going to be 16 same projects in the class...and different approaches are expected from all the groups... and i thought that most of the ppl opt for ir and solenoids...so i can try this and stand out... and already gave a basic idea with arduino...so cannot change later on unless some major problem comes up.... well and for the size i would love to shrink on it...cause i do need to save some weight

and it has to be used thrice...there are going to be three flights and the package should be dropped on the target each time... and it can be by any means, sound light ir or anything...but all these being common for these projects...i have opted for something else...

well i just gave a report saying i would be using arduinos...so i would love to hear any number of ideas...cause i will be continuing this even after my project as a hobby...

thanks again for all the replies...!!

The yellowjacket and its clones are Arduino compatible.

You want to use Arduino in the plane or Arduino to program a chip to put in the plane?

The chips are AVR's, the -development board- is Arduino.

It is poor engineering to stick with a component or solution based on "I said", aka Ego, over "this is better". Not kidding here, I've seen businesses eat that shirt more than a few times before. You won't look bad for coming up with a better solution but you will for stubbornly sticking with a poor solution.

Thomas Edison had Nikolai Tesla as his employee. Tesla kept trying to sell Edison on AC power but Edison with so much in DC would not accept it even though shown that a DC power grid would not work. Edison pulled a lot of dirty stunts (including killing animals in public with AC current) to try and get AC power stopped. He set himself and would not see different. Westinghouse backed Tesla, AC power rightfully won and Westinghouse got the business, starting with the generators at Niagara Falls and going far beyond. Edison didn't go broke but he lost out on opportunities big enough to make light bulbs look like a side-show act. He was even kicked off the board of General Electric which he had formed and was the head. The only real why was his own ego, refusing to admit he made a mistake. IMO Edison was an idea and credit stealing jerk anyway but that's just me.

Fully agree. BTW: Tesla has a SI unit named after him, Edison has not.

that is what i want to know…
what components should i exactly use to get a wireless circuit work…
i need help on that…
and as of now…i have just given a report that mentions the basic components…which is just arduinos, txr, rxr, servos…
i might have to stick to arduinos…but i can still change the rest…if i get a few good options…