Post by thread:[EE] CDMA or something similar....to send data ove

I'm going to explain best I can in simple terms....and I think there have been some on the list that has either looked at this or implemented it. Essentially looking at using the existing celluar phone system to transmit data back and forth to remote modules. Each remote unit would have a PIC (duh) collecteing data and storing it, where it would "phone home" now and then reporting what it found. These are remote sites, so having a phone line there (that would be easier then) to call is not always possible. So, questions: 1. Is CDMA the most widely used system in the states? ie....want to make sure there is a service provider that can be interfaced with. 2. What does it take, given that a CDMA (or like) module is used, to interface to a cell system? Obviously need a phone number established, but are they serial interfaced so you can activate it, dial and connect via that method? OR Are there cell phones now (my phone calls....gets calls.....has a voicemail box..so im not into tech phone gadgets) that have a built in serial port that you can simply do all of that just using the PIC UART.....dial....send serial data....hang up. Think what I'd really like to see is to be able to log into a server and just dump the data...there isnt alot of it to transmit so even 56K would be more than enough. Perhaps I am over simplying the whole thing..... --------------------------------- Discover Yahoo! Get on-the-go sports scores, stock quotes, news & more. Check it out!

> THats the hard part now.....the interface protocol. > Are there published specs on these? Please line-wrap your messages! Just hit return every 80 chars or so. Makes life easier for some. Check out http://www.bitpim.org. It's an open-source cellular phone interface program. I gather that it does both cell phone as a modem as well as accessing phone book and ringtones. I think the modem part is called "BitFling". I could be wrong, though. At any rate, looking at the protocols they used for the PC program MAY give you some idea of how to do ith with a PIC. Of the four phone models I've used with BitPim (LG VX6000, VX4400, VX8000 and VX7000), all four supported a USB-to-Serial bridge, and all seem to convert the signal to serial internally anyway (i.e., Windows "sees" the phone as an extra serial port). The VX4400 didn't even support native USB. Good luck! Mike H.

As far as I know (based on some USB/phone links as well as some PCMCIA cards) they're generally just set up as a serial link with the actual I/O being Hayes codes. - Marcel alan smith <spam_OUTmicro_eng2TakeThisOuTyahoo.com> wrote: > OK...course right after I post....got thinking....of course.....cell phones have > been interfacing with serial ports for a while...and sure enough there are > cables...to plug into a usb port. And drivers. > THats the hard part now.....the interface protocol. Are there published specs > on these? > > > > --------------------------------- > Discover Yahoo! > Have fun online with music videos, cool games, IM & more. Check it out!

below. alan smith wrote: >I'm going to explain best I can in simple terms....and I think there have been some on the list that has either looked at this or implemented it. > >Essentially looking at using the existing celluar phone system to transmit data back and forth to remote modules. Each remote unit would have a PIC (duh) collecteing data and storing it, where it would "phone home" now and then reporting what it found. These are remote sites, so having a phone line there (that would be easier then) to call is not always possible. > > What you are asking is happening right now. The PIC works great as a data logger. > >So, questions: >1. Is CDMA the most widely used system in the states? ie....want to make sure there is a service provider that can be interfaced with. > > GSM and CDMA are split on useage in the USA. However CDMA is the more advanced system, especially for data transfer work. >2. What does it take, given that a CDMA (or like) module is used, to interface to a cell system? Obviously need a phone number established, but are they serial interfaced so you can activate it, dial and connect via that method? > > The CDMA module must be approved by the FCC and also approved by the particular carrier you want to use. Pretty simple to activate, a cellphone number is activated and the service established. > >OR > >Are there cell phones now (my phone calls....gets calls.....has a voicemail box..so im not into tech phone gadgets) that have a built in serial port that you can simply do all of that just using the PIC UART.....dial....send serial data....hang up. > > I have no idea. > >Think what I'd really like to see is to be able to log into a server and just dump the data...there isnt alot of it to transmit so even 56K would be more than enough. > > > You can adjust the CDMA module to accept anything from 9600 to 115kb. These are pretty smart modules. At first, its a few AT commands, then your PIC requests PPP access, providing an destination IP address#:port# as well as an account name and password. You can then pass whatever is needed. Once you get past the 500pg manuals, its just a primitive PPP account by means of a simple modem. Look at http://www.wavecom.com . > >Perhaps I am over simplying the whole thing..... > > why not oversimplify? Make everybody else do the work- I'm old and tired. --Bob > >--------------------------------- >Discover Yahoo! > Get on-the-go sports scores, stock quotes, news & more. Check it out! > > -- Note: To protect our network, attachments must be sent to .....attachKILLspam@spam@engineer.cotse.net . 1-866-263-5745 USA/Canada http://beam.to/azengineer