Post by thread:modems easy (and cheap)

Does anybody knows about an single chip modem (2400bps) cheaper then the CERMETEK module CH1786 (1 to 9 units = $62.50ea ! ). It's not a problem for me if it uses some external components. I'm looking for other options (others than Rockwell RC224ATF). All ideas, places, manufactures and prices are welcome. See you, Beto.

If you can make do with 1200bps, you can get an SX chip to do it. You'll find code and an appnote at http://www.scenix.com -Randy Glenn E-Mail: spam_OUTPICxpertTakeThisOuTyahoo.com Web: http://i.am/PICxpert Currently wondering why I can't get in to Safe Mode - where's a Mac when you need it? {Original Message removed}

Speaking of the Cermetek modem modules, does anyone know if there is anything special that needs to be done to connect one of them to a PIC? We are currently trying to replace an off-the-shelf modem with one of these modules. But it doesn't seem to be communicating. The PIC never understands anything from the modem and the modem doesn't understand the PIC. (It's a 16C74A). We had a 232 chip in the circuit to talk to the standard modem, and we just removed that and wired directly to the Cermetek module. When I didn't work we wired some LED's in the the TX and RX lines to see if any data was flowing, and it is. Thanks, Jim Dossey Roberto Fonseca Iannini wrote: > > Does anybody knows about an single chip modem (2400bps) cheaper then the > CERMETEK module CH1786 (1 to 9 units = $62.50ea ! ). > It's not a problem for me if it uses some external components. I'm > looking for other options (others than Rockwell RC224ATF). > All ideas, places, manufactures and prices are welcome. > > See you, > Beto.

part 0 3851 bytes A MAX232 inverts the data.  Are you sure that this module requires non-inverted data? Mike <UL> {Original Message removed}

Take a look at AN724. It shows a PIC with a Cermetek modem used for PPP dialup access to the Internet. The hardware (3 wires direct from the PIC to the modem) and software are all there. And yes, the MAX232 does invert, so if you didn't change any code when you removed it that could be the problem too, unless you were using a *pair* of MAX232's... Dale --- The most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" (I found it!) but "That's funny ..." -- Isaac Asimov > Speaking of the Cermetek modem modules, does anyone know if there is > anything special that needs to be done to connect one of them to a PIC?

On Mon, 21 Feb 2000, Dale Botkin wrote: > Take a look at AN724. It shows a PIC with a Cermetek modem used for > PPP dialup access to the Internet. The hardware (3 wires direct from > the PIC to the modem) and software are all there. And yes, the MAX232 > does invert, so if you didn't change any code when you removed it that > could be the problem too, unless you were using a *pair* of > MAX232's... for you lazy guys: "Using PICmicro MCUs to Connect to Internet via PPP" http://www.microchip.com/10/Appnote/Category/Internet/00724/index.htm Cermetek site: http://www.cermetek.com/ They list the "lowest cost" CH1786NH module for $28US/1,000. An evaluation kit is $99+. Other modem chips: http://www.hitex.com/chipdir/abc/m.htm - j

Perhaps the Z-80 2400 baud modem would work? Andrew On Sun, 20 Feb 2000 22:42:58 -0300 Roberto Fonseca Iannini <.....roberto1KILLspam@spam@LINKEXPRESS.COM.BR> writes: > Does anybody knows about an single chip modem (2400bps) cheaper then > the > CERMETEK module CH1786 (1 to 9 units = $62.50ea ! ). > It's not a problem for me if it uses some external components. I'm > looking for other options (others than Rockwell RC224ATF). > All ideas, places, manufactures and prices are welcome. > > See you, > Beto. ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: dl.http://www.juno.com/get/tagj.

Check Silicon Labs at http://www.silabs.com -- Rich On Sun, 20 Feb 2000, Roberto Fonseca Iannini wrote: {Quote hidden}> Date: Sun, 20 Feb 2000 22:42:58 -0300 > From: Roberto Fonseca Iannini <roberto1KILLspamLINKEXPRESS.COM.BR> > Reply-To: pic microcontroller discussion list <.....PICLISTKILLspam.....MITVMA.MIT.EDU> > To: EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU > Subject: modems easy (and cheap) > > Does anybody knows about an single chip modem (2400bps) cheaper then the > CERMETEK module CH1786 (1 to 9 units = $62.50ea ! ). > It's not a problem for me if it uses some external components. I'm > looking for other options (others than Rockwell RC224ATF). > All ideas, places, manufactures and prices are welcome. > > See you, > Beto. >