Modems with respect to microcontollers...

[cubdh23]

Hi, I have been recently reading this book " PRogrammers guide to serial communications" It doesnt talk at all about microcontroller, its actually a VB and VB.net book on serial comm. Anyway im reading a lot about modems in this book and it seems that the modem using similar signals to RS232. I guess what im trying to ask is, Is the modem an important peripheral that can be used with microcontrollers to communicate with other PC's or other microcontroller... I dont explain myself well since english is my 2nd language so sorry. Can modem be a bridge between microcontroller and internet? Has anyone ever done this. What im thinking is maybe there can be uses like remotely keeping track of your home, sending commands through the modem and getting feedback from the controller and view it on a webpage. Is this possible and if so what all do i need to read on about?
thanks

 

[checkmate]

Try not to venture off too far.
Serial communication is simply using the COM port to transfer data between the PC and a peripheral, which may be a modem, a microcontroller circuit, or even another PC.
But using a simple microcontroller to connect to the internet through a modem is no easy task.

 

[Exo]

yes, it can be done but it won't be simple...

basically a modem converts rs232 signals to a signal that can be sent over a phone wire. If you have two modems connected to the phone lines and you let one modem 'dial' the phone number where the other modem is connected you will have a link and can communicate RS232 as if the 2 were connected straight together.

The tough part in this is getting to know the modems commands to 'dial a certain number'.

 

[cubdh23]

IM just curious but does the Ethernet card work the same way as the modem. Im not planning on working on this anytime soon im just trying to get a general grasp. Ok you say the modem transfers 232 signals to analog over line and recieves and has the same 232 signals again. Does ethernet card work completely differently from this or is it similar except for the dialing functions i would think. Since modems are obsolete i was starting to wonder about ethernet cards and how they would be useful. IM sorry if im asking too much questions, im just at work and bored out of my mind. Is Hyperterminal program the main program that would be used for such things? what all cool things can u do with hyperterminal i was playing with it for the first time yesterday and i didnt get too far but it seemed interesting.
CUBS GET NOMAHHH
#### yeah.
thanks
bye

 

[Exo]

No, an ethernet card works completely diffirent...

Hyperterminal allows you to monitor what's coming in trough the serial port, or dump files to the serial port

 

[Exo]

this might be interesting to you
https://www.electro-tech-online.com/custompdfs/2004/08/00724c.pdf

 

[cubdh23]

Very nice article thank you.
Ok now i understand what u mean by , Leave it alone its no easy task
or some earlier poster that said that .

 

[Exo]

The application note is about connecting a picmicro to a ISP trough a modem, most of it deals with the communication with the ISP. If you just want to connect 2 pics togheter trough modems (no ISP, just a straight Pic-Modem-phone line-Modem-Pic) then you only need the system to dial a certain number.

just make the modem dial the phone number where the other modem is connected to and you've got a straight connection