7 Replies Latest reply on Aug 29, 2017 7:59 PM by clem57

    Raspberry pi usb dialup

    gam3t3ch

      Has anyone gotten a USB 56k modem to work? I have a few and was pondering a idea with them.

        • Re: Raspberry pi usb dialup
          balearicdynamics

          Hello Wesley,

           

          not at all. Interesting this idea; can I ask what is the user for modems?

          Anyway USB modems are not a big mess to make them working with Pi. Just consider them as USB to Serial (should be verified but it is easy that this is the connection of them). Then after the bare physical connection of the peripherals there are many ways to make them working, from terminal up to a C program or Python. I think that as all the modems they work with a set of AT commands. What you need is a complete list of the supported commands by your modems.

           

          This link - https://www.computerhope.com/atcom.htm - is just an example of the incredible quantity of manuals and online lists of the AT commands. Consider that the USB modems supporting the GSM connection includes some extra commands to manage SMS and other GSM-specific features. Then not all the AT standard (HAYES command set) are always supported by all devices and in addition there are some extra AT commands that are device-specific, enable by a special AT standard Escape Sequence.

           

          Just to make a test of your serial connection, the ATE will generate and echo on the terminal and AT+ if I am not wrong will send back an OK string when the modem is ready. ATD will enable the external phone line communication on both GSM and non-GSM models.

           

          Enrico

            • Re: Raspberry pi usb dialup
              gam3t3ch

              I plan on making a field computer using a raspberry pi and wireless line only and a dial in server at my house to use I am not sure how in depth I am going to go into it but have had the idea a few years now and decided I should probably start building it.  The field computer would also be able to mounted and solar charged and powered for longer duration's in the wilderness allowing remote access and live feeds in the mountains.   I would love to have a 360 video camera setup as well on it for that.   

               

              Why a computer like this?  For data collection mainly and to make something I have wanted to for a while.   I have a spot in mind which would put it near a repeater station but out of sight but in site of the tower I thought this would be great for doing some sdr and being able to transmit from there to my local station the only thing I would have to try to figure out is a auto dial system for it which I don't think should be too hard.

               

              I think there is a lot I have to get sorted yet for this project but the main thing was making communication to a host computer for collection of the data was my primary concern.    Plus one day I would love to work on top of a mountain.  but that being said I want the cost to be as low as possible.  using gsm sounds like it would be ideal but for my project I am opting for lower budget dialing out.  I would be using a wireless home phone system which has a 3 day battery life which in turn would be great for cloudy days to prevent the system from going down. 

               

              I hope some of this makes sense, thanks for you reply I greatly appreciate it.

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                • Re: Raspberry pi usb dialup
                  balearicdynamics

                  IMHO this has sense Wesley. I have done something similar some years ago in an industrial environment to collect data and send instructions via remote from terminal (also from mobile) to a PLC network controlled by this way.

                   

                  My only concern is your idea to use fixed (wired) phone lines instead of GSM I think that just the GSM modem can give you a lot of benefits but the traditional phone line especially lowering the budget. There are more options you can manage with this kind of implementation that with fixed lines you can't. For example with the very low cost of a SMS you can send a lot of remote controls, including knowing when data are available and other useful information without spending time and money to schedule periodic transfers. Then as far as I know today there are worldwide good data only mobile plans that can solve the budget problems. Last but not least, as you speak of imaging (I suppose will be part of the data to collect) a fast 3D or 4G (and cheap) connection is more reliable and trustable than a phone line. 

                   

                  Enrico

              • Re: Raspberry pi usb dialup
                shabaz

                Hi Wesley,

                 

                You may have better luck with a serial port modem, connected to the Pi through a USB-to-RS232 adapter. This is in case some USB modems are a soft-modem which could be missing drivers.This is just speculation thouugh, I've never tried it, maybe USB modems are ok. Definitely worth a try if you already have one, using the commands balearicdynamics says Some businesses still use modems(as a backup connection to control(say equipment at remote sites and some of them use the  RS-232RS-232 modems since a lot of older equipment is missing the USB port anyway

                1 of 1 people found this helpful
                • Re: Raspberry pi usb dialup
                  gam3t3ch

                  Wow thanks guys for all the info,  first I guess I should mention the connection would be to a gsm home phone wireless unit.  but would not have data capabilities.

                  wireless-modem.jpg

                  Similar to this one here.

                   

                  I do also still have my USB-to-RS232 adapter laying around not doing anything as well. 

                   

                  This is the usb 56k modem I was hoping to use but I have other usb ones as well so hopefully something would work.

                   

                  56k.jpeg

                   

                  And then would create a linux dial in server on the collection terminal.  Still lots to work out for sure but greatly appreciate everyone input here this is awesome! Thank you all.