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ITBP modems and RPI 4 (or other RPI) integation. Debian 10 [Raspbian Buster] notes.


About this

This tutorial address the Raspberry PI 4, 3B+, 3B, 3A+, II, B, Zero and Zero W software integration with modems [full size or modular, 2G / 3G / 4G or LPW LTE CATM], including our u-GSM modem family [~22 modem types having BBB P9 interface embedded].


Most of the hardware related notes regarding modem integration will be exemplified for u-GSM modem, but will find references for the other modems.


Raspberry PI 4 with u-GSM LTE modem [EG95/EG91/BG96/BG95-Mx]

Involved parts

* BC95G (do not be confused with BG95-M2 or BG95-M3) does not have ppp support included.

** first generation itbrainpower modular modems does not have RPI interface integrated, but still can be interfaced with RPI using wires. Same interfacing directives may be applied for u-GSM modems SMA version!


note@20230227 => I stress you again! LiPo/LiION battery OR super-capacitor are REQUIERED for proper u-GSM functionality! *

* for low power LTE u-GSM modems used in LTE-CATM or NBIoT mode only [BG95-M2 and BG96/BG95-M3 having 2G mode restricted], the LiPO battery or the super-capacitor can be safely replaced with 1000-1500uF/6.3V LOW ESR capacitor.



Some RaspberryPi [4 or other] and u-GSM hardware references u-GSM shield it is the worldwide first (and the only one) modular modem that supports ALL deployed GSM standards [LTE NB IoT / LTE CATM1 / LTE CAT4 / LTE CAT1 / UMTS-3G / GSM-2G] in one unified design! Read u-GSM part numbers, radio protocols and country coverage to find the modem suitable for your application.


u-GSM RaspberryPI interface [and ITBPMM interface]

u-GSM modem pinout and embedded RaspberryPI interface



RaspberryPi interfacing w. u-GSM via embedded RPi hat interface

RaspberryPI with u-GSM modem + super-capacitor assembly

RaspberryPI and u-GSM modem w. super-capacitor assembly

More RaspberryPI u-GSM hardware integration info.



RaspberryPI with u-GSM modem + LiPO assembly

RaspberryPI and u-GSM modem w. LiPO battery assembly

More Raspberry u-GSM hardware integration info.


HINT: for low power LTE modems used in LTE-CATM or NBIoT mode only [BG95-M2 and BG96/BG95-M3 having 2G mode restricted], the LiPO battery or the super-capacitor can be safely replaced with 1000-1500uF/6.3V LOW ESR capacitor.



For a painless hardware integration (including PCB trimming how to) mandatory reading: u-GSM and RaspberryPi [4] hardware integration guidelines and antenna notes.



Dedicated hardware information for modem interfacing via ITBPMM interface using wires

This applies to u-GSM modem SMA version and first version of ITBP modular modems (c-uGSM, h-nanoGSM, d-u3G or l-LTE). You may ignore this if the u-GSM integration it's performed as described above.


Simple connect the wires as shown bellow:

RPI PIN12 [GPIO18]        <====> ITBPMM STS

RPI PIN16 [GPIO23]        <====> ITBPMM ENA / ITBPMM POW

RPI PIN18 [GPIO24]        <====> ITBPMM RST* / ITBPMM RST

RPI PIN08 [GPIO14 / TX] <====> ITBPMM TX

RPI PIN10 [GPIO15 / RX] <====> ITBPMM RX



RPI PIN04 [5V]    <====> ITBPMM Vin



Dedicated hardware information for full size modems interfacing

This applies to a-gsmII, b-gsmgnss and a-gsm modems. You may ignore this if do not use one of those modems.


Simply follow the hardware integration section here.



Linux Debian 10 [Raspbian Buster] install information and hints

Platforms compatibility: RASPBERRY PI any version including Raspberry PI 4.


u-GSM Debian support packages are available here: u-GSM shield download section.


Easy and fastest approach - use the RPI image patched for itbp modems:

Access the download section, select your shield type and download the last available RPI image patched for ITBP modems. This image is based on Raspbian Buster Lite 2019-09-26.

One micro SD card [at least 4Gb #] it is required for installation of this Linux image [Install a RPi image how to or google for it.]
Some features:
* static ETH0:0 IP address []
* sshd enabled
* enabled root access [1234 default password] [including root remote access enabled]
* maintained "rpi" user, having "raspberry" as password
* USB drivers
* mapped USB drivers for UMTS / LTE modems
* modified/remapped hciuart service [enabled BTH support over /dev/serial1 @ 115200bps]
* four additional packages installed [ppp, python-serial, mc and mtr]
* disabled avahi-daemon
* compact size 4Gb image [expanded] #

# for smaller SD (2Gb) - use patched image based on Streach Lite 2018-06-27(but not RPI4 compatible) from download section.

If you like to know what's changed/patched in this Linux image, read next chapter.



Custom install [Debian Buster Lite]

Download and install last Debian Buster Lite image from, or use your image.

Follow the same steps described in our RPI software how to, but:

a. first, remove "console=serial0,115200 console=tty1" from "/boot/cmdline.txt" ("cmdline.txt" on SD boot partition)

b. next, add in "/boot/config.txt" ("config.txt" on SD boot partition) following four directives:

c. ignore step 4(done before) and step 10!

d. optional, disable the "avahi-daemon" by running following three commands as root:
systemctl disable avahi-daemon.socket avahi-daemon.service
systemctl mask avahi-daemon.socket avahi-daemon.service
systemctl stop avahi-daemon.socket avahi-daemon.service









Original how to written by Dragos Iosub & team





document version 1.01 / 2020-01-06 © R&D Software Solutions srl