Control a motor remotely with cell phone signals

[kpk250]

Hey Guys,
I'm a mechanical engineer (please forgive my ignorance) with an electrical engineering problem. I'm trying to control a small DC motor with speed and duration controls using a remote cell phone. I might also like the ability to receive temperature data from the motor back at the cell phone. Can this be done? How? Do they sell off the shelf cell phone receivers or something similar for this purpose?

Thanks for your time and help,
Kris

 

[mgb_phys]

You can buy gsm modems that simply take a SIM card and will make and receive SMS messgaes and send them out on a serial port.
Then you just need a small computer (like an Arduino) to read the commands and control the motor

 

[dlgoff]

Welcome to Physics Forums kpk250. My first thought of a way is to use SCADA but I'm not sure how you could interface with a cell phone. There's a wiki page on it.
http://en.wikipedia.org/wiki/SCADA"

 

[kpk250]

Well i guess in envisioned a very small final form for this device. Say 1in x 1in x 2in long. I know that probably means a custom PCB and circuit right? But maybe I can use an existing circuit and design and shrink it down and strip away the unnecesary components/functionality.

 

[Topher925]

Exactly which method of protocol or communication are you looking at using? If your planning to control the motor directly from just the cell phone signal output, your in for a challenge. If you have a phone that has internet access and want to control something from it over the internet, that's going to make things a lot easier.

Why is it you want to control this motor with a cell phone? Is the idea that you can control this motor from almost anywhere with this device? If only short distance communication is required, there are much simpler ways of doing this.

And yes, more than likely you will have to make your own PCB and have to work with QFN chips. Hope your good with a hot air gun.

 

[Topher925]

Heres a link to some cellular development boards that will probably fit the bill. Keep in mind that in order to use these you will require a GSM account for it.

http://www.sparkfun.com/commerce/categories.php?c=66

 

[dlgoff]

Heres a link to some cellular development boards that will probably fit the bill. Keep in mind that in order to use these you will require a GSM account for it.

http://www.sparkfun.com/commerce/categories.php?c=66

Nice Tropher. I'm bookmarking this one.

 

[bassplayer142]

You could use a bluetooth module that is set to output in serial. I just used one to connect a wii remote to a computer, then the computer to the bluetooth module, out to my microcontroller, and then to a robot!

 

[kpk250]

Hey Topher925,
First off thanks for taking the time to reply and offer some help. Yes, the idea is to be able to control this motor from anywhere, preferably with text messages sent to the device. I took a peak at the link you suggested, but I must admit all of that is over my head (I even had to google GSM to see what that meant!). What do the boards on that site enable me to do?

Why would it be easier if the phone and device were linked through the internet?

This device (where the motor is located) will be mobile as well so it won't have the luxury of connecting to a network or wifi spot.

 

[mgb_phys]

See also http://www.hwkitchen.com/products/gsm-playground/

GSM is the standard for mobiles in most of the world (except bits of the USA). The workings of the phone part are normally a single sealed module because there isn't much you can change and the cell phone companies don't want random home made electronics connecting to their networks - so the unit is fixed and certified.

The GSM modems normally have a serial port connection and let you dial and receive calls and send/receive text messages just like a regular modem - except with no phone line.
The arduino is a simple cheap single board computer for interfacing to things like this.

 

[kpk250]

Thanks mgb_phys. So the GSM Playground board receives and redirects the text message to the Arduino board, and then the Arduino board deciphers the text and turns on the dc motor, right?

If so, the only problem is size. I need the whole system (GSM Playground, Arduino, Lithium battery, and antenna) to fit within a 1in x 1in x 2in long package. The GSM playground has some functionality that I don't need. Can it be repackaged into a suitable circuit that is smaller?

 

[Topher925]

Hey Topher925,
First off thanks for taking the time to reply and offer some help. Yes, the idea is to be able to control this motor from anywhere, preferably with text messages sent to the device. I took a peak at the link you suggested, but I must admit all of that is over my head (I even had to google GSM to see what that meant!). What do the boards on that site enable me to do?

Why would it be easier if the phone and device were linked through the internet?

This device (where the motor is located) will be mobile as well so it won't have the luxury of connecting to a network or wifi spot.

There are three different types of boards for that link. The 'breakout boards" are basically just PCBs that give you simpler access to the modem so you don't have to do any fancy soldering to use the GSM modem. The "evaluation boards" are like the breakout boards but include stuff like voltage regulators, connects, and a few other things the modem needs to operate. The "development boards" basically include everything you will need for this project with the exception of the GSM SIM card which you will have to purchase separately. This includes the GSM modem itself, antenna, relays, peripherals, battery backup, and a microcontroller to control it all along with some other stuff. You will need to buy a GSM SIM card no matter which board you purchase.

In order to use these development boards you have to know how to use the microcontroller that's on them, (PIC and AVR are two of them). If you have no experience with microcontrollers, which it sounds like you don't, I suggest you don't get a development board.

I suggest you get one of the evaluation boards like this http://www.sparkfun.com/commerce/product_info.php?products_id=9311". I think your limit of 1x1x2 inches is a bit unreasonable though. To make something that size you're going to need to design your PCB and circuit. All the components I suggest would still be good for development and prototyping though.

If you have never done this stuff before, there will be a steep learning curve but its certainly doable. I'm an ME also and if I can do this stuff, anyone can.

 

[kpk250]

Hey Topher925.
Cool thanks. It is slowly coming together...at least in principle.

What's the different between the Arduino Pro Mini and the Arduino Nano 3.0. The Nano seems more capable and is about the same size (other then the obvious .1 connector posts boardering the PCB).

I also have a fundamental mobile phone/communication question. Once I have the hardware figured out, I need a SIM card right. Does that mean I need to connect to a cell phone provider network somehow to get service and start communicating back and forth to the GSM modem and my iPhone 3G? If so, how is that done?

Thanks again.

 

[Topher925]

Hey Topher925.
Cool thanks. It is slowly coming together...at least in principle.

What's the different between the Arduino Pro Mini and the Arduino Nano 3.0.

One is 10 bucks cheaper I guess? I'm not really sure they seem to be pretty close to the same thing to me.

Once I have the hardware figured out, I need a SIM card right. Does that mean I need to connect to a cell phone provider network somehow to get service and start communicating back and forth to the GSM modem and my iPhone 3G?

Yes. That is the entire purpose of the SIM card. The SIM (Subscriber Identity Module) card is basically the ID that the phone company uses to identify the device. Think of it as your cell phones social security number. The SIM card is how your phone (or what ever device you have it in) is identified and also has the phone number tied to it. So your motor controller will have its own phone number and sort of be like a super-dooper glorified cell phone.

 

[Arpita.koli]

i want project based on remote motor speed control using cell phones

 

[kocthu]

From my point of view, you should not spend a lot of money to control this small valued DC motor. Its not a worth. So you might need only cell phone detector circuit and micro-controller circuit. It may give your wish.