A7670C sim module can not make calls but able to send messages

Projects Networking, Protocols, and Devices
1

Currently, I am using a USB to ttl adapter for the A7607C sim module. module I use

I am able to send SMS messages just fine, However, whenever I try making phone calls it just gives me an "ERROR". I also tried turning on verbose errors and it only says Error. I have a German Sim and I am trying to call a friend that has a dutch sim card. So I have been trying to use the command "ATD+31..." (+31 is the country code for Dutch phone numbers). I have also tried not having the + sign, tried doing + and even ++. But none of these options work. I read the data sheet and it says that ATD+31... should be fine, however I can't seem to get it to work

Any help would be much appreciated!

2

Some SIM cards may be limited to domestic calls only. Try to call to the German phone numbers.

3

I am able to call my friends when I have my sim card in my phone, and I also tried calling a german number and it did not work either. Though maybe it’s because I am in Netherlands with a german Sim. Thank you for your response though, I’ll try borrowing someone else’s sim card :slight_smile:

4

It could be a power problem or incorrect code.

How you powered the modem? The modem requires a strong power when making calls.

5

I am powering it through my laptop using 5v, not sure about the current because for some reason it wasn’t showing the current, but I’d assume it’s around 1A? Is that enough?

6

Do you mean laptop USB connected to arduino? Nominal USB2.0 output is only 500ma, while the modem can require up to 2A when connects to network. You definitely need an external power for it.

7

Ok thank you so much! I’ll try it out :)))