Turn on Arduino Wirelessly, passivly that is.

Development Boards Arduino
1

Hi, I was just thinking of something.

Parts:

Arduino UNO

RF Transmitter

Passive RF Receiver

Battery Pack / Power Supply / Something

Bluetooth Module

Transistor

Some kind of amplifier (or not?)

Some kind of transformer

Would it be possible, to turn on an Arduino wirelessly for example by doing this:

Have some kind of transmitter, a regular RF transmitter like this http://www.dx.com/p/433mhz-rf-transmitt … 9xYJK3xW7I and some kind of passive receiver (any suggestions by the way?), meaning that there is no supply power for the receiver.

Transmitt a high signal to the receiver, amplify (or not? need power for that?) and transform the voltage to for example 5V or something less, transform it into a voltage that i could use.

We then have a transistor that we use as a switch, the 5V (or whatever) we got from the transformed signal will be used to change the “state” of this transistor/switch (ON/OFF), when turned ON it will let through 5V (From a battery pack or any kind of power supply) for the Arduino, which then powers on and keeps the circuit closed by outputting 5V to the transistor we used as a switch until set LOW, and the Arduino turns off.

Of course, in the code of the Arduino you make it output HIGH right away as it starts, when I want to turn the Arduino OFF i send a command through the bluetooth module or USB telling the Arduino to output LOW maybe have it turn OFF by itself after a given time of inactivity.

The thing is that I want to turn OFF every part of my project completely without having to press a physical button, but also being able to turn ON everything without using a physical button. If that’s not possible I’ll just have to use a button :slight_smile:

No it doesn’t have to be this transmitter nor RF at all, if IR could work I’d use that, something that lets me do this wirelessly.

So my question was as you can see under the Parts list Would it be possible, to turn on an Arduino wirelessly for example by doing this, and then I also wonder, how?

2

Just use the button.

All switches, of any type and without exception, require energy to operate. Otherwise the device would violate laws of physics.

3

The thing is that, if you read the PDF that i just attached, Passive Receivers are something that we have been using once, I want to exploit the energy of the Radio signal, to possibly charge up a circuit which changes the state of the transistor to ON (Closed).

I found the PDF here http://prod.sandia.gov/techlib/access-c … 044610.pdf.

4

Sure, you can extract energy from a radio signal and use that energy to power something, or turn a device on.

Below is a picture of a microwave oven leakage detector made using a PCB loop antenna, an LED and a germanium diode.

See http://www.creative-science.org.uk/mobile_LED.html

http://molbio.uoregon.edu/~remington/microwave_det.JPG

5

Super, thank you for your answer :smiley:

6

Don’t get your hopes up. While the latter suggestion is a wireless method, it may not be appropriate. TheJonaMr, you never mentioned at what distance you needed the arduino to be activated. The suggested coil-led example may be wireless. But it is only barely working contactless. (hence the suggestion of simply going for a pushbutton) Same goes for other RF or magnetic coupling powering schemes. You need to hold the transmitter close for it to work exciting the receiver.

7

True True.

Since you mentioned it, the distance I hoped that it would work with is up to 4 meters.

8

That’s a definite no-go for this.

But I really do not understand your requirement of a receiver without powersource. You have an Arduino with a powersupply or battery that must be switched on by this, yet the thing that switches it on must be without it’s own powersource!?! Makes no sense. Sure, you’d want the receiver to use as little of power as possible to extend battery life. But why not use the Arduino powersource?