This article will help to figure out how to send AT Commands to iPhone 4. The commands will be sent via iPhone shell. We've already published the list of AT commands and the tools that will help you to send that commands. In this tutorial we will use minicon (you can install it from Cydia) or just follow the link above to review the tools which can be used for communicating with your iPhone's baseband. To install minicom from Cydia you should do next things. After installing the package itself check if the folder /usr/etc exists. Connect to your iPhone through SSH and then type in:

minicom -s

after that continue setting up the ports and all the other things as usual. If you're not sure how to do that or just want to remind yourself of something within the installation process - read this post to get the detailed instructions on how to install and configure minicom. In /dev folder you can find interfaces like this:

 iPhone4:/dev root# ls /dev
 aes_0 io8logmt tty.highland-park
 bpf0 klog tty.iap
 bpf1 mux.spi-baseband tty.umts
 bpf2 null ttyp0
 bpf3 pf ttyp1
 btreset ptmx ttyp2
 btwake ptyp0 ttyp3
 console ptyp1 ttyp4
 cu.bluetooth ptyp2 ttyp5
 cu.debug ptyp3 ttyp6
 cu.gas-gauge ptyp4 ttyp7
 cu.gps ptyp5 ttyp8
 cu.highland-park ptyp6 ttyp9
 cu.iap ptyp7 ttypa
 cu.umts ptyp8 ttypb
 disk0 ptyp9 ttypc
 disk0s1 ptypa ttypd
 disk0s2 ptypb ttype
 disk0s2s1 ptypc ttypf
 dlci.spi-baseband.call ptypd ttys000
 dlci.spi-baseband.chatty ptype uart.bluetooth
 dlci.spi-baseband.cl1 ptypf uart.debug
 dlci.spi-baseband.extra_0 random uart.gas-gauge
 dlci.spi-baseband.iq rdisk0 uart.gps
 dlci.spi-baseband.low rdisk0s1 uart.highland-park
 dlci.spi-baseband.pdp_0 rdisk0s2 uart.iap
 dlci.spi-baseband.pdp_1 rdisk0s2s1 uart.umts
 dlci.spi-baseband.pdp_2 sha1_0 urandom
 dlci.spi-baseband.pdp_3 tty vn0
 dlci.spi-baseband.pdp_ctl tty.bluetooth vn1
 dlci.spi-baseband.reg tty.debug zero
 dlci.spi-baseband.sms tty.gas-gauge
 io8log tty.gps

The /dev/dlci.spi-baseband.extra_0 worked fine for me but I can't guarantee it will do the same for you. Setup minicom properly to make it work:

 iPhone4:/dev root# minicom -s

after that select "Serial port setup" and press A and edit the line of the serial device (for me was that):

 A - Serial Device : /dev/dlci.spi-baseband.extra_0

Type esc and "Save setup as dfl", then exit and type:

 iPhone4:/dev root# minicom -w

for connecting to the device. Afterwards type in AT. If you get an "OK" response - everything should now work like a charm If not - double check the "serial port setup" settings. To make a call to the 3931111100 number simply type:

 atd3931111100;

for hanging up:

 ath

To obtain the sim serial number (iccid number) type:

 at+ccid

To get your phone's imei number put in:

 at+cgsn

That's basically all the steps you need to make to send AT Commands to iPhone 4. Looks pretty easy if you know at least what minicom and SSH is, right? If you need to connect to iPhone 5 BB use this guide. Let us know how it worked for you in the comment section under the article.