I've started on a project that entails two Arduinos (ok, one of them is technically a 3.3 volt "Teensy" instead, the other one is a standard 5 volt Arduino Uno).
How easy is Virtual wire to use?
So far, what I have is....
"The outside unit"...intended to be near the doorway outside. It has the Teensy, a transmitter, and a sensor. When the sensor senses, then it is supposed to transmit....is it true that a lower bitrate is transmitted better than a higher one?
"the inside unit"....a main Arduino, hooked up to a receiver, and a servo (that would be part of a feeding mechanism) The inside unit could be connected to a power supply (can you "power it" via USB?) When it picks up the signal, the servo will rotate, to drop some dry dog food. This is because the dog gets excited when someone goes by. This will train her.
The outside unit needs some kind of power (as plugging it would not be feasible)
I'd not rate it as hard as some other things, but its harder than flashing a LED?
.is it true that a lower bitrate is transmitted better than a higher one?
As you are only sending a small amount of data, it doesn't really matter, you could send at 1200 baud and it would be fast enough to tell your unit inside that there was a movement.
The outside unit needs some kind of power (as plugging it would not be feasible)
Solar + battery ??
How should I go about this?
You already seem to have designed it. I don't see any major problems.
Doe these Arduinos and Teensys have built in power supply? Or not really. Would I be able to just recharge the "outside" unit every so often? Or will I have to work in some kind of power source. If so, anything you can recommend? At 3.3volts, that is? (I chose a "teensy" to make the device not so big.)
No they are just circuit boards with components on them, they are not a complete consumer product with its own attached power supply.
At 3.3volts, that is? (I chose a "teensy" to make the device not so big.)
Why are using the Teensy?
Your project doesnt need the sort of processing power provided by the Teensy
Just use 2 normal Arduino boards, e.g a Uno
Externally, to use as little power as possible, you could use a Arduino Pro Micro on 3.3V if you really wanted.
However the best approach is just to turn the power on to the arduino and the transmitter when your detector senses movement
Most IR sensors have a setting that will allow the output to be held on for a minimum of 3 seconds, and up to 20 secs, which is plenty of time for the arduino to power up and send a small message via radio e.g. 433Mhz TX
Really all you need power for is to run the detector
No they are just circuit boards with components on them, they are not a complete consumer product with its own attached power supply.
So is there some kind of battery that's easy to attach? And if so, to what holes in the device? (yes, I'm new to this) And as for the internal one, can it be powered by USB? (the inside one can be attached to a computer)
Why are using the Teensy?
The name says it all. Reduced size. The "outside" part shouldn't be too big if it can be helped. Also got the smallest possible breadboard. Although the guy I'm making it for says he'll convert it to soldering eventually. But now the rub is the power supply. Any devices or something? Any power supplies that are teensy or Arduino ready? I'll get a "proper" Uno if that's what's needed.
It's a Teensy 3.0 by the way, not a 3.1, since that would be overkill for what's being done.
The name says it all. Reduced size. The "outside" part shouldn't be too big if it can be helped
See Arduino Mini, its smaller and cheaper than the Teensy. The Teensy is a high performance board not required for the very simple project you are doing.
Some of the components you will need are likely to be...
Arduino Micro (or pro mini ) or Arduino Nano for your use the Nano would be the easiest to use, I like the Micro as well, but the USB can be a bit odd, so its not ideally suited to novices, Pro Mini is good but needs external RS232 interface for programming
Cool, looks like the internal one is USB powerable. So, best kind of battery or other "small" external power source for the one that's attached outside the door? (with the motion detector and the transmitter)