Using Nova with PPP on embedded platform w/o SDK


#1

Hello Hologram,

I’m working on a project using the Nova board with a custom embedded Linux board we designed. I’m trying to establish an internet connection without using the Hologram CLI/SDK. I’ve been working on the ppp interface, but I am having some trouble getting the interface up and running.

When I call the ‘pon’ command, the chatscript does run, and the Nova’s blinking LED goes solid blue for about 3 seconds before shutting off. Checking the log, I’m getting a message that ‘LCP terminated by peer’, so it looks like my ISP is hanging up when the Nova calls for a connection. Log:

root@APSA_rev4:/etc/ppp# pon
root@APSA_rev4:/etc/ppp# pppd[1472]: pppd 2.4.4 started by root, uid 0
chat[1473]: abort on (BUSY)
chat[1473]: abort on (NO CARRIER)
chat[1473]: abort on (VOICE)
chat[1473]: abort on (NO DIALTONE)
chat[1473]: abort on (NO DIAL TONE)
chat[1473]: abort on (DELAYED)
chat[1473]: timeout set to 12 seconds
chat[1473]: report (CONNECT)
chat[1473]: send (AT^M)
chat[1473]: expect (OK)
chat[1473]: AT^M^M
chat[1473]: OK
chat[1473]: – got it
chat[1473]: send (ATH^M)
chat[1473]: expect (OK)
chat[1473]: ^M
chat[1473]: ATH^M^M
chat[1473]: OK
chat[1473]: – got it
chat[1473]: send (ATZ^M)
chat[1473]: expect (OK)
chat[1473]: ^M
chat[1473]: ATZ^M^M
chat[1473]: OK
chat[1473]: – got it
chat[1473]: send (ATQ0^M)
chat[1473]: expect (OK)
chat[1473]: ^M
chat[1473]: ATQ0^M^M
chat[1473]: OK
chat[1473]: – got it
chat[1473]: send (AT+CGDCONT=1,“IP”,“bandwidth”^M)
chat[1473]: expect (OK)
chat[1473]: ^M
chat[1473]: AT+CGDCONT=1,“IP”,“bandwidth”^M^M
chat[1473]: OK
chat[1473]: – got it
chat[1473]: send (ATDT99*1#^M)
chat[1473]: expect (CONNECT)
chat[1473]: ^M
chat[1473]: ATDT
99***1#^M^M
chat[1473]: CONNECT
chat[1473]: – got it
chat[1473]: send (^M)
pppd[1472]: Serial connection established.
pppd[1472]: Using interface ppp0
pppd[1472]: Connect: ppp0 <–> /dev/ttyACM0
pppd[1472]: LCP terminated by peer
pppd[1472]: Hangup (SIGHUP)
pppd[1472]: Modem hangup
pppd[1472]: Connection terminated.
pppd[1472]: Exit.

I’ve validated that the SIM card is working and enabled. By using the same Nova with a Raspberry Pi, I’ve been able to get on the internet with this SIM card through the Hologram CLI. So, there is something that the Hologram scripts are doing that my ppp scripts seem to be missing. I think there may be a handshaking step that I am missing when I try to use ‘pon’ directly.

Do you have a guide or example of establishing an internet connection using the PPP interface, instead of the Hologram CLI? Or, is there a flowchart or document describing the connection steps that the Hologram CLI commands go through? Appreciate any support!

-Chris


#2

The CLI really doesn’t do much extra to start a PPP session. You may want to compare your chatscript and peers file to the ones in here: https://github.com/hologram-io/hologram-tools/tree/master/ppp/


#3

Thanks for getting back to me. I actually was able to identify the issue this morning. I had an incorrect keyword for my ISP (AT&T in this case) in my chatscript:

AT+CGDCONT=1,“IP”,“bandwidth”

should instead be:

AT+CGDCONT=1,“IP”,“broadband”

I must’ve gotten mixed up and typed in ‘bandwidth’ by mistake instead of ‘broadband’. Once I had corrected this, I was able to run pon, get an IP address, and ping websites right away. Hope this might help someone else in the future.

Thanks again for the support Reuben!

 -Chris

#4

Cool, makes sense. Glad you got it working


#5

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