at command - SMS and GPRS: Multiplexing GSM module on BeagleBone Black using n_gsm -


i'm using simcom 800h cellular module beaglebone black similar popular simcom 900. want 2 main things simcom module

  • use @ commands configure settings , send , receive messages
  • use ppp enable internet access on bbb through gprs.

now obvious problem cannot both @ same time. did web search , found following posts

  1. using gprs , gsm simulatneously
  2. sending @ commands sim900 whilst pppd active

the 2nd link has been particularly useful 1 of user has used code on repository.

the common theme has been use n_gsm module. tried load module using modprobe n_gsm , failed. user mentioned bbb doesn't include n_gsm module default had go , build new kernel n_gsm added module. i'm having issues including n_gsm module. here steps followed

  1. i followed this tutorial , downloaded right linux headers bbb.

  2. i tried compile module linux lkm (loadable kernel module) follows

  3. i downloaded n_gsm.c here

  4. the n_gsm.c file had includes missing in bbb. downloaded them.
  5. i created makefile. directory had n_gsm.c , makefile

makefile

obj-m += n_gsm.o  all:     make -c /lib/modules/$(shell uname -r)/build m=$(pwd) modules  clean:     make -c /lib/modules/$(shell uname -r)/build m=$(pwd) clean

this generated errors shown in figure n_gsm errors

  • i able load different module shown in this (the hello world of kernel modules). dont understand why need recompile entire linux kernel create lkm.

  • i feel i'm making obvious errors looks people able load module successfully.

  • is right way load module , n_gsm. there isn't document/tutorial on this.

  • is there simpler way multiplexing in case thisdoes not workout? idea of @ commands sms , ppp gprs (instead of @ commands both).

any tips , suggestions helpful!

edit1 : details bbb

  1. kernel - linux beaglebone 3.8.13-bone79
  2. distro - debian 7.9 (wheezy)

edit 2 : added details gsm module

  1. this gsm breakout board i'm using.
  2. it uses this module , can checkout command manual , multiplexing application note.

update 1

  1. thanks @serge, able build n_gsm module , add without re-compiling kernel. however, still haven't been able gsm module mux mode.
  2. at+cmux=?, at+cmux? , at+cmux= geneated error on sim800h module.
  3. here's de-bugging have done
    1. played around hardware/software , no flow. didnt work in mode.
    2. set te-ta fixed local rate at+ipr auto, 115200 , still at+cmux generates error
    3. tested at+cmux? on sim900 module , works.

any idea why not work sim800h?

the make issue in question has been solved downloading n_gsm.c beaglebone's kernel source repository kernel version in use.


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