Modem Challenge

SciNemo

My PropComp is nearing version 2.0 and the one thing that I keep pushing off the list of features-to-do is the internet. I have this 56K modem that was laying in my junk box and I think it might be possible to use it with the propeller. My challenge to all of you Prop hackers out there is to figure out how it would be possible to connect this to my Propeller and have it connect to the internet (or to a home computer over phone lines).

Here is what I have managed to scrounge up in the way of info, which isn't much:

Specs-
# AMR 1.2 Modem
# PCTel chipset (PCT303L / PCT303A)
# 56K V.90 standards
# AMR interface (v1.2B)
# Two (2) RJ-11 phone line jacks (Line and Phone)

Here is a picture of it that I found on the internet:


Any help at all is greatly appreciated. I'll have to think of some way to award the person who figures this out, but for now it is for brownie points

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Not the fish.
sites.google.com/site/bitwinproject/

Post Edited (SciNemo) : 6/8/2009 12:46:22 AM GMT

Clock Loop

First thing you need to do find the datasheet for the primary IC.

I tried to search on google and found nothing.

And acutally, a picture of the pcb with all chips on it would help.

Get the numbers off every IC. Then find the datasheets for EVERY IC.

After you find the datasheets for every IC then you might be getting somewhere..

But I somehow think that this pctel device may have relied mostly on software...
They call em' "winmodems" i think...

But like I said, your not going to get anywhere without exact datasheets that match your IC's.

Post Edited (BPM) : 6/8/2009 12:50:46 AM GMT

Oldbitcollector (Jeff)

Why not simply go external? RS232 modems are robust and the creation of a simple serial connection is one chip (MAX3232) away.

OBC

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New to the Propeller?

Visit the: The Propeller Pages @ Warranty Void.

BradC

BPM said...

But I somehow think that this pctel device may have relied mostly on software...
They call em' "winmodems" i think...

BPM is spot on. That is a controllerless modem designed to have all the DSP work done in software in the HOST PC. File it in the circular filing cabinet and pick up an external modem like OBC suggested [noparse]:)[/noparse]

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"VOOM"?!? Mate, this bird wouldn't "voom" if you put four million volts through it! 'E's bleedin' demised!

Beau Schwabe

SciNemo,

I can't tell if that card is ISA or PCI... If it's ISA, it's not that hard to decode how the pins are talking to the PC, and from my own experience of building several ISA cards you could most definitely do all of the decoding with a Propeller. I'm not sure about the PCI standard, the timing is a bit more critical and I don't know it as well. Most modems will accept a standard AT commands set so regardless of the type of modem you are using, the AT commands should work for basic communication.


Edit:

I didn't catch what BPM said at first... You need a modem that does all the work, so technically all your doing is sending and receiving the raw BYTE data through the ISA or PCI buss

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

Post Edited (Beau Schwabe (Parallax)) : 6/8/2009 5:03:33 AM GMT

trodoss

Multi-Tech Systems (and others) make embedded modem modules that could be used, if you didn't want to use an external modem.· If you are going to that sort of trouble though, you might as well go for an ENC28J60-based solution, and avoid dial-up.

Kye

That's a

http://en.wikipedia.org/wiki/Audio/modem_riser

or

http://en.wikipedia.org/wiki/Communications_and_Networking_Riser

or

http://en.wikipedia.org/wiki/Advanced_Communications_Riser

Those cards should be easy to communicate with because they feature no on board processing. However, this means the prop has to do more.

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Nyamekye,

SciNemo

I suppose I will just have to buy a simple RS232 modem, I doubt I can figure out how to interface the board I have myself.

So now my question is, what is the best and cheapest RS232 modem that I can buy that will get my propeller connected to the internet?

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Not the fish.
sites.google.com/site/bitwinproject/

Matthew Burmeister

you could emulate a modem with a FCC DAA approved circuit

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Disclaimer: I cannot guarantee any information i post is accurate, but most of the time, it is correct.

known programming languages: SX/B, PASM, SPIN, BASIC, PBASIC, PICAXE BASIC, C/CPP, 8086 ASM

Misses 8 bit computing

StefanL38

Hewllo SciNemo,

as you want to connect to the internet where almost everything is based upon UDP and TCP/IP why not changing to the ethernet-chip ENC28J60

ENC28J60 Ethernet PHY/MAC Chip Driver
and the
Ethernet ENC 28J60, complete demo

or using any kind of embedded webserver with a RS232-interface

best regards

Stefan

SciNemo

That chip is exactly what I wanted to set up. Thank you very much for all the info, maybe sometime in the future I'll try and tackle the old 56K modem.

I found an ethernet module being sold on Sparkfun that uses that chip and suits my purposes perfectly.

www.sparkfun.com/commerce/product_info.php?products_id=765

I have a new question though, is it possible to use this to connect my Propeller to my home computer anywhere in the world, and if so, how would I do that with the released object for the chip?

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Not the fish.
sites.google.com/site/bitwinproject/

Post Edited (SciNemo) : 6/11/2009 2:13:50 AM GMT

hinv

How about one of these?
shop.ebay.com/items/?_nkw=enc28j60&_armrs=1&_from=

They are pretty tiny and cheap!


Doug