LTE CAT-M1, NB IoT, LTE CAT4, LTE CAT1, UMTS and GSM IoT modem ** u-GSM

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Unique modem form factor that supports ALL existing GSM protocols [LTE CAT M1, NB IoT, LTE CAT 4, LTE CAT 1, 3G/UMTS and 2G/GSM], depending on embedded module variant.
Being a master piece of design, u-GSM is the unique world-wide modem shield that can be directly plugged to Raspberry PI or to BeagleBone Black and covers all GSM standards:
- [Low Power LTE] CAT M1 + NB-IoT [CAT NB1 and NB2] + EGPRS + GNSS - Quectel BG95-M3 module
- [Low Power LTE] CAT M1 + NB-IoT [CAT NB1 and NB2] + GNSS - Quectel BG95-M2 module
- [Low Power LTE] CAT M1 + NB-IoT + EGPRS + GNSS - Quectel BG96 module
- [Low Power LTE] NB IoT - Quectel BC95G embedded module
- LTE CAT 4 + 3G/UMTS + GSM - Quectel EG95x embedded module
- LTE CAT 1 + 3G/UMTS + GSM - Quectel EG91x embedded module
- 3G/UMTS + GSM - Quectel UG96 / UG95x embedded module
- 2G / GSM / GPRS / EDGE - Quectel M95FA embedded module
More info about available versions and modem performances [bands, transfer speeds, protocols supported]: part numbers and description.

Raspberry PI embedded interface: Plug directly the u-GSM shield into Raspberry PI GPIO interface. Raspberry PI 4, 3+, 3, II, B+, Zero and Zero W are supported.

BeagleBone Black embedded interface: Plug directly the u-GSM shield into BeagleBone Black P9 GPIO interface.

u-GSM shield can be powered directly from RPI / BBB 5V PINs!! - thanks to integrated LiPO / LiIoN battery charger.

GNSS [GPS + GLONASS] engine: High performances GNSS engine embedded having parallel GALILEO, GPS and Glonass satellites interpolation for best sensitivity and accuracy. The GNSS module it is embedded only in u-GSM versions equipped with BG95-M3, BG95-M2, BG96, EG91A and EG95A.

Embedded USB adapter - with mini-USB type B socket and USB soldering pads. Raspberry PI and BeagleBone Black Linux [DEBIAN] and Windows drivers support.

ITBPMM* interface having 3-5V auto voltage support for UART[TX, RX] and control GPIOs [ENA, RST, STS and RI]
- u-GSM may be wired directly (without the need for any level adapter board) with any 3/5V Arduino shield or any version of RASPBERRY PI, BEAGLEBONE, other SBC or any other 3V-5V microcontroller.
- available trought 0.1"(2.54mm) BIG SIZE soldering pads.

Multiple powering configurations - the u-GSM shield can run in configurations with or without Lithium Polymer battery, depending on chosen powering schema.

SIM support: 1 x NANO SIM/USIM socket + 1 x external SIM interface.

Very compact and light weight: 27 x 45mm [main partition -wo RPI&BBB interfaces] / around 10g.

Arduino, BeagleBone and RaspberryPI code examples support files: - 4G, LTE, 3G, UMTS, GSM, SMS, DTMF, TCP/UDP, HTTPS and HTTP over 4G/3G/GPRS*, smart features like RAM DISK SYSTEM for FILE STORAGE and other.

RaspberryPI and BeagleBone PPP, TCPIP routing support (Debian distribution based) and modem control scripts.

* ITBPMMI - modular modem interface - compatible with any of our modular modems [c-uGSM dual SIM shield, h-nanoGSM shield, d-u3G shield and l-LTE shield]



u-GSM shield v2.19 - pinout description
u-GSM shield v 2.19 - top PCB detail 1
u-GSM shield v 2.19 - top PCB detail 2
u-GSM shield v 2.19 - bottom details


In the left edge of the top PCB side, bottom to top:
1. RX[TXD] - modem TX - output
2. TX[RXD] - modem RX - input

3. RST - MODEM RESET - input, active HIGH*
4. ENA - ENABLE MODEM POWER - input, active HIGH**

5. Vusb - POWER PIN - output +5V (USB +5V)
6. Vin - POWER PIN - input +5V for LiPol charger only
7. Vcc - POWER PIN - input/output +4V**

9. RI - RING INDICATOR - output
10. STATUS - STATUS - output
* min. 250msec. pulse [HIGH level] will RESET the modem, excepting BG95-Mx and BG96 variants. RST pin have alternate functionality, as POWER ON / POWER OFF / exit PSM mode, for BG95-Mx and BG96 variants.
** HIGH level will enable modem power. All u-GSM variants, excepting BG95-Mx and BG96, will be waked [POWERED ON].
** LOW level disconnects the modem power. All u-GSM variants will shutdown.
*&** To wake BG95-Mx or BG96 variants, keep ENA pin to HIGH level and then apply 250ms HIGH level pulse to RST pin.

Raspberry PI embedded interface

In the PCB top side left hand, from left to right:
RPI02 - Vin <--> RPI 5V*
RPI04 - Vin <--> RPI 5V*
RPI06 - GND <--> RPI GND
RPI12 - STS <--> RPI GPIO18
RPI16 - ENA <--> RPI GPIO23
RPI16 - RST <--> RPI GPIO24
* Read about sjp7 functionality bellow.
** Read about sjp5 and sjp6 functionality bellow.

BeagleBone Black embedded interface

In the PCB top side right hand, from right to left:
P9.01 - GND <--> BBB GND
P9.02 - GND <--> BBB GND
P9.05 - Vin <--> VDD 5V* ***
P9.06 - Vin <--> VDD 5V* ***
P9.11 - RX[TXD] <--> GPIO_30[UART4_RXD]**
P9.12 - RST <--> GPIO_60
P9.13 - TX[RXD] <--> GPIO_31[UART4_TXD]**
P9.15 - ENA <--> GPIO_50
P9.16 - STS <--> GPIO_51

* Read about sjp7 functionality bellow.
** Read about sjp5 and sjp6 functionality bellow.

LEDs, switches and additional interfaces

PCB top edge, left to right:
1. RST switch - RESET function for all versions, excepting BG95-Mx and BG96. POWER ON / POWER OFF / exit PSM mode for BG95-Mx and BG96 variants
2. GREEN LED - network status LED
3. YELLOW LED - power status LED
4. GNSS u.FL connector [only for BG95-Mx, BG96, EG95A variants]
5. LiPO / LiION battery connector [GND, +]

Left PCB side, inside PCB, from top to bottom:
1. GND - super-capacitor soldering PAD, negative pole
2&3. Vbat - super-capacitor soldering PADs, positive pole

PCB bottom edge, from left to right:
1. USB connector type miniB
2. USB soldering PADS [GND, D-, D+, Vusb]

Right PCB edge:
1. nano SIM socket connector

Solder jumpers

sjp1* - RESERVED - default circuit closed.

sjp2 - Active GNSS antenna powering - default, the active GNDD antenna power is enabled [circuit closed]. Relevant only for BG95-Mx, BG96 and EG95A variants.

sjp3 - disable LEDs powering - default, LEDs power is enabled [circuit closed]. STS [STATUS] signal is disabled if LEDs power is disabled.

sjp4 - bypass modem power separation - default disabled [circuit open]. If enabled, ENA input will lose its role.

sjp5 and sjp6 - connect modem UART to RPI and BBB embedded interfaces - default connected [circuits closed]. If disconnect, RPI/BBB RX and TX GPIOs will be released. You may like to use this option if modem is connected to RPI/BBB via USB.

sjp7* - connect Vin to BBB/RPI 5V - default connected - u-GSM us as power supply 5V from RPI / BBB [circuit closed]. If disconnect, u-GSM may be powered independent.

BBB voltage selector* - use BBB Vdd 5V / SYS 5V as power source - default Vdd 5V is used as power source. Relevant if u-GSM is connected with BBB.
sjp5, sjp6, sjp7 and BBB voltage selector are relevant only if u-GSM is connected to BBB/RPI via embedded interfaces.
* consult u-GSM block schema.

External SIM CARD port, antenna connector

External SIM card interface
- if not used, leave them not connected
- if used, in order to avoid interferences, keep the wires as short as possible and take in to account the routing.

GSM side antenna connector
u-GSM shield may be ordered with u.FL connector or with SMA F connector. Check here: u-GSM part numbers.

PCB breaking lines

If required the u-GSM PCB may be trimmed across the breaking lines. We recommend to you to trim the u-GSM PCB only if you intend to fit your Raspberry PI & u-GSM shield assembly into one RPI case.
Guidelines here.


u-GSM shield :: Arduino / Raspberry PI logical interfacing [using ITBPMM interface]

u-GSM shield PIN NAME UNO/MINI/NANO (Mega328) MEGA2560 software serial DUE or MEGA2560
hardware serial
Raspberry PI 4, 3+, 3, II, B+, ZERO, ZERO W
1. RX[TXD]* D2 (RX soft) D10 (RX soft) D19(RX1) PIN10 (RX)
2. TX[RXD]* D3 (TX soft) D3 (TX soft) D18(TX1) PIN08 (TX)
3. RST D6 D6 D6 PIN18
4. ENA D7 D7 D7 PIN16
6. Vin (5V LiPol)** +5V +5V +5V PIN02 or 04
8. GND GND GND GND PIN04 or 14
10. STS [STATUS] D5 D5 D5 PIN 12
* Raspberry PI: do not wire 1 and 2 (serial TX and RX) if USB comunication is used!
** WITH Lithium Polymer batteries configuration: wire 6 (Vin) OR do not wire it and use via USB powering placing a jumper between PIN5 (Vusb) and PIN6 (Vin). Read notes about u-GSM powering configuration on:
- u-GSM v2.19 modular modem shield block schema

- ITBP modular modem shields how to start - tutorial RECOMMENDED READING
- gSPS adapter board - plug and run switching power supply for the ITBP modular modems

Raspberry PI interfacing logical schema:

RPI - u-GSM shield logical interfacing schema.

Raspberry PI interfacing using i-HAT adapter (without wires) how to:

Raspberry PI, i-HAT adapter and modular modems how to.

Arduino Zero or xyz-mIoT modem-less shield interfacing:

1. RX(TXD)       <----->       RX0
2. TX(RXD)       <----->       TX1

3. RST              <----->       D6
4. ENA              <----->       D7

6. Vin               <----->       5V power supply
8. GND             <----->       GND
10. STS            <----->       D5


u-GSM shield :: Raspberry PI logical interfacing [using Raspberry PI embedded interface]

Apply the directives described in: u-GSM SHIELD RASPBERRY PI HARDWARE HOWTO.

- due to mechanical reasons, this variant cannot be used for u-GSM shield with SMA integration.
- we recommend to you to trim the u-GSM PCB only if you intend to fit your Raspberry PI & u-GSM shield assembly into one RPI case.


u-GSM shield :: BeagleBone Black logical interfacing

Variant a. Interfacing using BeagleBone Black P9 embedded interface

Due to mechanical reasons, variant a cannot be used by u-GSM shield with SMA.

Variant b. Interfacing via ITBPMM interface

Follow directives in: BeagleBone Black and ITBP modular modem interfacing how to.
This variant allow integration for u-GSM shields having SMA connector.



Resources marked with "#", requires for download the following information: your name, email address and the modem IMEI. The modem IMEI can be found printed on the Quectel GSM module, or run AT+GMGS command.

u-GSM shield code examples for Arduino, Raspberry PI and BeagleBone Black can be downloaded from our download page.


The u-GSM shield documentation can be found here.


Arduino & RaspberryPI projects based on products


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document version 1.2 / 2022-11-14 © R&D Software Solutions srl