Hi, I’ve established a connection to the network and was able to access the web via my RPi 4B housed in a 4” TFT Touch screen with a SIM7600 LTE HAT.
I have powered this with a 6A power supply and have configured the chatscript and provider files as shown below.
I have also ran the AT commands and provided the output. Can someone please point me in the right direction as to why I can’t maintain a connection to the network?
Network Check:
jameshayek@raspberrypi:~ $ ping google.com
ping: google.com: Temporary failure in name resolution
jameshayek@raspberrypi:~ $ ping 8.8.8.8
ping: connect: Network is unreachable
jameshayek@raspberrypi:~ $ sudo lsof | grep ttyS0
lsof: WARNING: can’t stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs
Output information may be incomplete.
lsof: WARNING: can’t stat() fuse.portal file system /run/user/1000/doc
Output information may be incomplete.
pppd 1491 root 10u CHR 4,64 0t0 133 /dev/ttyS0
Status of PPP:
jameshayek@raspberrypi:~ $ sudo systemctl status ppp-autoconnect.service
● ppp-autoconnect.service - PPP auto-connect for LTE HAT
Loaded: loaded (/etc/systemd/system/ppp-autoconnect.service; enabled; pres>
Active: active (exited) since Sun 2024-02-25 21:07:41 EST; 22min ago
Process: 1450 ExecStart=/usr/bin/pon (code=exited, status=0/SUCCESS)
Main PID: 1450 (code=exited, status=0/SUCCESS)
Tasks: 1 (limit: 8734)
CPU: 75ms
CGroup: /system.slice/ppp-autoconnect.service
└─1491 /usr/sbin/pppd call provider
Feb 25 21:07:42 raspberrypi pppd[1491]: Serial connection established.
Feb 25 21:07:42 raspberrypi pppd[1491]: Using interface ppp0
Feb 25 21:07:42 raspberrypi pppd[1491]: Connect: ppp0 ↔ /dev/ttyS0
Feb 25 21:07:43 raspberrypi pppd[1491]: PAP authentication succeeded
Feb 25 21:07:43 raspberrypi pppd[1491]: Could not determine remote IP address: >
Feb 25 21:07:43 raspberrypi pppd[1491]: not replacing default route to wlan0 [1>
Feb 25 21:07:43 raspberrypi pppd[1491]: local IP address 10.170.1.79
Feb 25 21:07:43 raspberrypi pppd[1491]: remote IP address 10.64.64.64
Feb 25 21:07:43 raspberrypi pppd[1491]: primary DNS address 8.8.8.8
Feb 25 21:07:43 raspberrypi pppd[1491]: secondary DNS address 8.8.4.4
lines 1-20/20 (END)
Provider File Details:
jameshayek@raspberrypi:~ $ sudo cat /etc/ppp/peers/provider
user " "
connect “/usr/sbin/chat -v -f /etc/chatscripts/gprs -T hologram”
/dev/ttyS0
115200
noipdefault
usepeerdns
defaultroute
persist
noauth
Chatscript File Details
jameshayek@raspberrypi:~ $ sudo cat /etc/chatscripts/gprs
Cellular Network Connection Script
This script is used in conjunction with the PPP daemon to establish a cellular network connection.
The APN is specified in the PPP peers configuration file and passed to this script via the -T option.
Standards reference: 3GPP TS 27.007 - AT command set for User Equipment (UE).
See: 3gpp for AT command details.
ABORT BUSY
ABORT VOICE
ABORT “NO CARRIER”
ABORT “NO DIALTONE”
ABORT “NO DIAL TONE”
ABORT “NO ANSWER”
ABORT “DELAYED”
ABORT “ERROR”
Abort if the modem is not registered with the network
ABORT “+CGATT: 0”
“” AT
TIMEOUT 30
OK ATH
OK ATE1
Uncomment and modify the next line if a SIM PIN is required
Replace ‘YOUR_PIN’ with your actual PIN number
#OK “AT+CPIN=YOUR_PIN”
Configuring handset for full functionality
#OK AT+CFUN=1
Setting the APN provided by the cellular network operator
The ‘\T’ token is replaced by the APN specified in the peers file
OK AT+CGDCONT=1,“IP”,“\T”,“”,0,0
Dialing command to initiate the data call
OK ATD*99#
TIMEOUT 22
CONNECT “”
Note:
I found i have a provider file along with the gprs file. I renamed the provider file to provider.old since I’m using the gots file to set modem configurations.
jameshayek@raspberrypi:~ $ sudo cat /etc/chatscripts/provider
This is the chat script used to dial out to your default service provider.
Please customize the entries enclosed in parenthesis to match your setup.
Only the “provider” file will be handled by poff and pon (unless with
extra command line arguments).
Remember to edit /etc/ppp/peers/provider accordingly.
ATZW2 as a default init string
- On all hayes compatible modems, W2 will correctly report the connect
speed.
ABORT BUSY
ABORT “NO CARRIER”
ABORT VOICE
ABORT “NO DIALTONE”
“” ATZW2
OK ATDT
ogin
word \q
jameshayek@raspberrypi:~ $
AT Test Results
jameshayek@raspberrypi:~ $ sudo systemctl stop ppp-autoconnect.service
jameshayek@raspberrypi:~ $ sudo minicom -D /dev/ttyS0
Welcome to minicom 2.8
OPTIONS: I18n
Port /dev/ttyS0, 21:07:42
Press CTRL-A Z for help on special keys
AT
OK
ATI
Manufacturer: SIMCOM INCORPORATED
Model: SIMCOM_SIM7600A-H
Revision: SIM7600A-H_V1.1
SVN: 03
IMEI: 868022030994565
+GCAP: +CGSM
OK
AT+CGMI
SIMCOM INCORPORATED
OK
AT=CGMM
ERROR
AT+CGMM
SIMCOM_SIM7600A-H
OK
AT+GMM
SIMCOM_SIM7600A-H
OK
AT+CPIN?
+CPIN: READY
OK
AT+CCID
+CCID: 8944500711212958027
OK
AT+CRSM=176,28539,0,0,12
+CRSM: 144,0,“130184130301FFFFFFFFFFFF”
OK
AT+CFUN?
+CFUN: 1
OK
AT+CSQ
+CSQ: 31,99
OK
AT+CREG?
+CREG: 0,5
OK
AT+CGREG?
+CGREG: 0,5
OK
AT+CEREG
OK
AT+CGDCONT?
ERROR
AT+CGDCONT?
+CGDCONT: 1,“IP”,“hologram”,“0.0.0.0”,0,0,0,0
+CGDCONT: 2,“IPV4V6”,“ims”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 3,“IPV4V6”,“sos”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,1
OK
AT+CGACT?
+CGACT: 1,1
+CGACT: 2,0
+CGACT: 3,0
OK
AT+COPS?
+COPS: 0,0,“T-Mobile Hologram”,7
OK
AT+COPS=?
+COPS: (3,“Verizon”,“Verizon”,“311480”,7),(1,“AT&T”,“AT&T”,“310410”,7),(3,"313 )
OK