Power on a phone

I am interfaceng Arduino with a Siemens S55 and a Siemens S65 and I can send GSM AT commands to it sucesfully.

My idea is to build a simple alarm that makes me a call when Arduino powers on (because I want only watch if there is power or not). I can do it.

But my problem is how can I power on the phone, because when it is power off I can't send AT commands to power it on.

I thinked in control power key in the phone in some way, but I have been looking for a solution and I can't find it (maybe a mosfet?)

Can anyone help me? I'm very beginner in electronic

Could you use a solenoid or a servo to push the power button?


Too expensive and complicated. I think is better open the phone and solder the contacts of the key to a reel or a mosfet

But... any other way simpler?

I disagree, unless you want to make it look pretty.

Just take a piece of wood, and put some nails or dowels in it to hold the phone in place. Mount the solenoid or servo to it, wire it to the Arduino, and the mechanical part is done. If there's a holster available for your chosen phone, that makes it really easy to make a solid mount that won't even mar the phone's paint.

If the only cheap solenoid you can find is a "pull" type, you might need to come up with an arm and a pivot. I'd use a Lego Technic beam. But I prefer the servo, because the gearing gives you more force per milliAmp, at a slight cost in speed that you don't really need. You should be able to buy a used one for US$10 or less, because you can use a servo that's not quite fast or precise enough for a radio control hobbyist.


Thanks Ran. Maybe you are right, but initially I only see mechanicals problems. I'm going to try with a reel and two cliped wires. I'll post news

I can't understand why you have to power on the arduino and the cell phone. If it's an alarm, I suppose there's the arduino connected to some sensors, and the phone. To monitor and send alarm you have to leave them powered on all the time. Otherwise you could turn the phone on or off by hooking the power button contact to one arduino pin and a pull-up resistor. The nice thing is that you could answer when the arduino rings, and hear the noises in the room :)

Agent Smith: My need is very simple. I need only know if somebody turn on the main power switch in my vacancies house. Then I only need Arduino for make a call or send a message when it boot. Simple.

And think if you donĀ“t use the battery and due to a blackout power is lost. Phone would not power one by itself.

Agent Smith and Ran: Finally I have done it puting a relay between the power button contacts, breaking the button.

Agent Smith: You say use a pullup resistor, without relay... Can you give me an schema? this is for apply a voltage, isn't it? but I apply only a contact with the relay, no voltage nor current. Safer I think.

hi, i m facing a problem with interfacing my arduino with a siemens. I cant send GSM AT commands to it sucesfully. i dont know, if there is a problem with software or hardware. Would you be so kind and send me your source code for serial communication between the phone and the arduino? thanks

That's my final job and it's working!!!

Please, take a look to this blog I've made. Here I explain how to make a very simple alarm with a Siemens S55 mobile and an Arduino Diecimilia that makes me a call when somebody come in my vacancies flat. It is written in spanish, but I'm sure google translator will make a good job with it.


magnox, i hope it will help you

thank you, i ll take a look at it.