Connecting 3g modem with arduino

I have a Huawei e160 3g usb modem, that i want to connect to an arduino . When connected to the pc, the modem is creating a serial port and simulate a cd rom with a software on it. I can then send at commands selecting the port created. Trying to connect it directly to arduino it does't work , because(i think) the data wires are not typical rx/tx serial connection. I tried to look for the pinout of the modem to find the rx/tx , but i could only find jtag pins.

I want to use the modem only as a gsm, sms sender and reciever with at commands.. (no internet or data transfering) I don't wanna use a usb shield with it( later i want to use it with an arduino mini pro). Does anyone have tried connecting a 3g modem to an arduino without a usb shield? Or have a sugestion to how can i connect it?

Most Arduinos don't have USB Host capabilities, so I'm not sure how you managed to connect this USB device to your Arduino

Which board do you have?

Also; The PC would have needed to load a driver to communicate with this USB device. There will almost definately not be any "driver" code for such a device even if your Arduino had USB host capabilities (i.e if you attached a USB Shield etc)

I didn't connect it to arduino. The basic idea of the project is to replace a bare boned mobile phone (which is a little to big for my like ) connected to an arduino pro mini , using 3 wires (serial rx/tx and ground) , with a 3g modem(which is preety small). The question was ; if anyone knows if there are serial connection pins(rx/tx like on the phone) on the huawei e160 3g modem , or if someone knows a 3g modem that have serial pins.

What you are trying to do is possible but quite difficult. You need a USB host shield to talk to any kind of USB device. The difficulty will be in finding out what the USB modem expects to see from the host controller. You wont find any 3g modems that have normal serial pins , they are all USB.

Well, i don't want to use a usb host shield, because is to big for my project. My sony ericsson phone, that i use right now for the project, has a usb port , but also has serial rx/tx and other pins on the pcb. The 3g modem has 28 round pins on both boards. I know what 10 of those are (jtag). But still ,there are 18 pins that i cannot find any documentation for what they are. And to try poking all of them to see if the AT commands work, its a bit too much. I know that the tx/rx are working from 1.7 to 2.7 V , but after measuring every pin for voltage , still there are 14 pins that i don't know what they do. I think i will try to solder wires to every pin , and try some combinations.