Debian 10 - ITBP modems and RPI 4 (or other RPI) integation

About this

This tutorial address the Raspberry PI 4, 3B+, 3B, 3A+, II, B, Zero and Zero W software integration with itbrainpower.net 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 itbrainpower.net modems.

Involved parts

• Raspberry PI 4 / 3B+ / 3B / 3A+ / II / B / Zero / Zero W
• any u-GSM modem uFL version (excepting BC95G version*) or
• any first version of ITBP modular modem (c-uGSM, h-nanoGSM, d-u3G or l-LTE **),

and mandatory one of the following:

• 1pcs. x LiPo battery [3.7V, > 250mA]***, or
• 1pcs. x super-capacitor for itbrainpower.net modems***.

* 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!

I stress you again! LiPo/LiION battery OR super-capacitor are REQUIRED for proper u-GSM &RPI assembly 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

itbrainpower.net 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]

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

RaspberryPI with u-GSM modem + super-capacitor assembly

More Raspberry u-GSM hardware integration info.

RaspberryPI with u-GSM modem + LiPO 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 PIN06 [GND] <====> ITBPMM GND
RPI PIN04 [5V]    <====> ITBPMM Vin

Dedicated hardware information for full size itbrainpower.net modems interfacing

This applies toitbrainpower.neta-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 [192.168.122.200]
• 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 Stretch 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 the last Debian Buster Lite image from https://www.raspberrypi.org/downloads/, 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:

enable_uart=1
dtoverlay=pi3-disable-bt 
dtoverlay=pi3-miniuart-bt 
core_freq=250

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

READY! TUTORIAL PROVIDED WITHOUT ANY WARRANTY!!! USE IT AT YOUR OWN RISK!!!!