Matrix user forums

Hello all:

I notice that there is a teaching module for mobile phone technology and a project for a cell phone audio "bug".

I want to build a cell phone video "bug" that would allow me to call a cell phone located in a remote location and to take and view real-time snapshots using the cell phone camera.

I don't need pan and tilt or audio although those capabilities might be nice.

This is in a rural area where there is no Internet access except via cell phone (or expensive satellite link) and no power. The cell phone would be solar powered with a rechargeable battery and be on 24-7.

Viewing the snapshots on a "calling' cell would be fine unless there is application software out there that would let my PC display the pics.

Has anyone out there already tackled this?

Jim

Hello

The control of taking photos and pan / tilt etc could all be done by sending the phone a text message. All the microcontroller would have to do is to parse the text that comes into it and try to pull out commands and data.

You would need either an external camera controlled via the microcontroller or you would have to do some fiddling with a phone handset to allow it to auto answer.

I like your solar powered idea for the phone.

Let us know how you get on with this project.

Ben:

I assume that the audio "bug" project implements auto answer. If so, how do you guys accomplish that? Do you have an external micro that is hard wired into various points of a cell phone such that the micro does the answering, etc.? If yes, would the same approach be a good starting point for a camera version?

Jim

With our Mobile phone solution we use a GSM modem that has a RS232 serial port.

All of the transactions are done over the RS232 bus.

This is where I am seeing the possible problems. You would need a mobile phone with a camera that you can interface to. Maybe quite a tall order. It may be easier to use a similar GSM modem and then use a camera combined with a frame grabber to collect the images. This could be then sent over the GSM modem as data.

Ben:

Where could I go to get information on the transactions that can be accomplished via the serial port?

I have an Ericsson cell phone with a serial port (and a built in camera) and application software that allows me to use the phone as a dial-up modem but, as far as I know, that is the only supported function.

Beyond dial-up, I have no idea of how to communicate with/control the phone via the port. Is there a "standard" set of commands or industry protocol?

Jim