I have an 3g dongle usm modem,I tested on windows works correctly
I tested on raspberry pi,using sakis3g software i got an error like
Modem responded "ERROR" while checking for PIN
I searched in google and try almost solutions but it does not work
I tested sending sms using gammu on raspberry pi and works correctly
sends sms without any error
but only internet connection has error

It's been a while...
https://wiki.archlinux.org/index.php/USB_3G_Modem

tnx for your solution
I tried this and i am sure my SIM does not have PIN but when i try to get internet connection by sakis3g i got error like
"Modem Responded "ERROR" While Checking For Pin"
I read that article in your post and i checked every possible issue but unfortunately got that error again

Then you have to give us more information:

• distro
• configuration: what you did to get it to work, packages installed etc.
• commands issued
• full output received (*)

(*) use CODE tags for that, see my signature.

HTTP request sent, awaiting response... 200 OK
Length: 200713 (196K) [application/octet-stream]
Saving to: ‘sakis3g.tar.gz’

sakis3g.tar.gz 100%[===================>] 196.01K 165KB/s in 1.2s

2020-02-18 06:12:38 (165 KB/s) - ‘sakis3g.tar.gz’ saved [200713/200713]

root@ehsan:~# tar -zxvf sakis3g.tar.gz
sakis3g
root@ehsan:~# chmod +x sakis3g
root@ehsan:~# lsusb
Bus 001 Device 005: ID 12d1:1001 Huawei Technologies Co., Ltd. E169/E620/E800 HSDPA Modem
Bus 001 Device 003: ID 0e0f:0002 VMware, Inc. Virtual USB Hub
Bus 001 Device 002: ID 0e0f:0003 VMware, Inc. Virtual Mouse
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
root@ehsan:~#
root@ehsan:~#
root@ehsan:~#
root@ehsan:~# ./sakis3g connect
Modem responded "ERROR" while checking for PIN.
Failed to connect.
root@ehsan:~#
----------------------------------------------------
ubuntu minimal:
Linux ehsan 4.15.0-76-generic #86-Ubuntu SMP Fri Jan 17 17:24:28 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
----------------------------------------------------
installed only:
ppp
usb_modeswitch
----------------------------------------------------
root@ehsan:~# dmesg | grep tty
[ 0.004000] console [tty0] enabled
[ 431.289811] usb 1-2.1: GSM modem (1-port) converter now attached to ttyUSB0
[ 431.290037] usb 1-2.1: GSM modem (1-port) converter now attached to ttyUSB1
[ 431.290310] usb 1-2.1: GSM modem (1-port) converter now attached to ttyUSB2

Does it have to be sakis3g?
https://duckduckgo.com/?kae=d&kp=-1&...for+PIN&ia=web
Doesn't look too promising.

What about NetworkManager/ModemManager? Or Wvdial?
Or like this: https://wiki.archlinux.org/index.php/USB_3G_Modem

I used wvdial but i got error again

Attached Thumbnails

 

^ you're not trying very hard, are you?

1 members found this post helpful.

why
I try 10000 time
and every time gets error
I am frustrated for dongle 3g huawei however it does work on windows very nice
I used dlink dongle accessed to internet but sms function does not work

How about reading wvdial's documentation before you start.