new project... feasible?

[scooterchief]

I apologise for my ignorance in advance but I am thinking of devoting a lot of time on this and need to see if it is feasible before I go out and buy/learn everything:
I don't own yet a mindstorm now but I want to build something that remotely wakes up the nxt for it to perform a certain task (it will be in a remote location and I cannot physically press its buttons) but I will have a computer near for it to connect via bluetooth or usb.

So,
1. can the brick be woken up via bluetooth/usb or whatever other method without pressing its orange button (this is what I've seen from all the videos so far), or
2. can it remain on - say by disabling an auto-sleep function? (does it have one?)

I this feasible? If you want more info please write to me as I am very excited and can't wait to start if this doable. Thanks.

[mattallen37]

The answer is no, you cannot turn on the NXT through BT or USB. The NXT doesn't have a "sleep" mode (like a low-power mode), so that's out of the question. You can however start a program using USB or BT, as long as the NXT is turned on, and able to communicate with the computer.

[dimasterooo]

In RobotC there is definitely a non-sleep function, but you'd have to keep the program running the entire time (shouldn't be a problem). If you combined that with a rechargeable battery (see the lego website; I'm on my phone so it's hard to get links working, sorry), you could probably get it to work because the NXT can function while the battery is plugged in. The only problem would be that your robot wouldn't be mobile.

For activating it, you could use mattalen's suggestion, or you could get the Dexter Industries WiFi sensor and try to get it to work using that. Check Xander's website, botbench.com - he used that sensor to set up a robot where anyone could input a motor speed on a webpage, which would then be sent to the NXT, which would then move its motors accordingly (the users could also see that actually happening on a live stream video of his robot; it was really cool). You could set it up so it activates some function or changes a variable to serve as a trigger.

And one more thing: what you want to do is pretty difficult, and might be very hard using NXT-G (I'm not even sure if the WiFi sensor is supported in that, but don't quote me). So I'd advice using either NXC, RobotC or something else like it. I personally use RobotC and like it a lot, and Dexter Industries posted a bunch of tutorials on how to use their WiFi sensor in RobotC last week, but it's not free (not too expensive either, but still not free).

[sidneys1]

Or you can look at Philo's excellent external power supply, although you can risk frying your NXT or electrocuting yourself... If you aren't an electronics-savvy person, don't try this one. I'm just saying it's hypothetically a solution for you.

Have a nice day,
~Sidneys1

[mattallen37]

In RobotC there is definitely a non-sleep function, but you'd have to keep the program running the entire time (shouldn't be a problem)...

Well, yes there is (supported in the standard FW as well), but it's a shut-off timer, not a low power standby mode.

[haydenstudios]

In RobotC there is definitely a non-sleep function, but you'd have to keep the program running the entire time (shouldn't be a problem)...

Well, yes there is (supported in the standard FW as well), but it's a shut-off timer, not a low power standby mode.

The reason that answer only consisted of keeping it from turning off was because it was focussing on his second question, not really his first one.

[mattallen37]

Okay, I see... But you can just set the NXT power off timer to "Never".

[scooterchief]

Ok great thanks a lot guys.
Actually I don't want it to be mobile, it will be a box sort of and any movement is within. Just to give you an idea I want to have the NXT punch in a code remotely on a keypad when I am not there (I travel alot). So basically I will connect to the NXT-attached (usb) computer and give the nxt the 'order'. As I need to see the result of my code in the keypad's display I am thinking of attaching a camera on the computer. But would it be possible to attach a camera on the nxt and have part of the nxt routine take a picture and save/send it in the computer? is that feasible?... food for thought. Thanks again.

[dimasterooo]

The only way I know of to attach a camera to an NXT is using Mindsensor's NXTCam, but thet's more for tracking objects and lines. It isn't really meant for taking photos, though it has been done: http://www.youtube.com/watch?v=iUfF0p8to_w. The quality is probably not good enough for your purposes though.

Something you could do is make the robot physically press the button on a camera, and then find some way for the computer to show you the picture you took. A webcam with skype or a live stream would probably work too.

A few more questions:
So the robot needs to be remote controlled?
What does the keypad look like? (the more complex it is, the harder it'll be to get a NXT to reach the keys with only three motors)