Read our last post: Modems and RaspberryPI 5. RaspberryPI OS [Debian 12 bookworm] notes.. Order u-GSM modems.

Important information - the a-gsm 2.064 shield is no longer in production.

Documentation and code support, last updated version, are still available for download here. The a-gsm v2.064 shield can be directly replaced by a-gsmII shield or by b-gsmgnss shield. All you need to do is to change the a-gsm libraries with a-gsmII or b-gnss shield libraries.

You may like to order online the a-gsm version 2 a-gsmII shield
same as a-gsmII but having GNSS engine embedded b-gsmgnss shield


Find bellow, arhived a-gsm v 2.064 shield information.



Quad band GSM/GPRS module (Quectel M85) with true worldwide coverage: 850MHz, 900MHz, 1800MHz and 1900MHz

INTEGRATED GSM antenna and connector for external GSM antenna thought u.FL connector;
DUAL SIM, SINGLE STANDBY - MAIN SIM card socket standard and,

SECOND SIM card socket (depends on ordered code) - (SIM cards required not included)

MicroSD card socket standard (support uTF cards up to 32 Gb),

USB adapter embedded standard - SERIAL to USB bridge adapter with micro-USB type B socket (you can use the a-gsm board as wireless modem with your PC, connecting it directly thought USB to your PC - Windows and Linux compatible),

SERIAL TTL interface, down to 3V compliant (TX and RX) available in Arduino pin-out,

SWITCH POWER Supply* with efficiency up to 95%; the shield can be powered using: Arduino Vin pin(5-12V), Arduino 5V pin and thought USB connector(*).

Audio in and out 3.5 stereo jacks standard - HIGH power audio output (700mW RMS) and capacitor Microphone interfaces embedded,

Embedded switches: control for modem ON/OFF & modem RESET and Arduino Reset

DIGITAL AUDIO interface and SERIAL2 (3V TXD and RXD) interfaces available thought additional back PCB side pads.
COMPACT FORMAT: 84.00x53.34mm, around 35g.
*        5V-38V input support, low consumption, 3 way powering profiles: USB, Vin pin or 5V pin with manually selector for users convenience

**      High Speed GPRS Multi-slot class 12 (configurable 1~12) Downlink and uplink speed - 85.6 kbps Max

Extended Arduino and RaspberryPI support, with code examples: - GSM, TCP/UDP, HTTP over GPRS**, DTMF, SMS and other features and utilities like micro-TF CARD FILE SYSTEM STORAGE, DUAL SIM, others.
RaspberryPI PPP and TCPIP routing support (RaspbianOS) trough easy installation and usage scripts.





GSM GPRS SHIELD - Arduino RASPBERY PI compatible a-gsm 2.064 top description

PIN definition:

Pin D2 = GSM TXD(RX),

Pin D3 = GSM RXD(TX),




PinRST = Arduino RESET OUT,

Pin5V = Arduino 5V,

PinVin = Arduino Vin,

Pin GND(1&2) = GND









Standard Arduino Pin-out - direct Arduino connection

ONE to ONE connection without additional cables for Arduino UNO/LEONARDO and Arduino MEGA ADK/MEGA 2560*
* Arduino LEONARDO & Arduino MEGA ADK/MEGA 2560, additional strap / 1k resistor may be needed


Easy RaspberryPI wiring

Connection name               RPi pin                       a-gsm shield pin

POWER a-gsm                   16                         D7  - power(UP/DOWN)

RESET a-gsm                    18                         D6  - reset *

a-gsm STATUS                  12                         D5  - status

serial TXD0                       08                         D3  - RX(TXD) 

serial RXD0                       10                         D2  - TX(RXD)

GND                                06(or 14)                GND - on Arduino power IN connector

5V power supply                02(or 04)                5V  - on Arduino power IN connector **

*        connection not mandatory

**      mandatory only for a-gsm powered from RPi; not mandatory for a-gsm powered separately: via USB connector or Vin.



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.

Download a-gsm kickstart for Arduino (COMPILABLE) CODE - version 0.92/0.96/0.971 0.9711/2016.07.15>>
a-gsm series software kickstart for Arduino # (zip)

DOWNLOAD ARDUINO RUNNING(COMPILABLE)CODE here - version 0.91 0.921/15.07.2016>>
a-gsm series GSM / GPRS / DTMF / SMS ARDUINO shield examples # (zip)

Preview bellow the Arduino GSM GPRS shield examples and how to run directives:

-          Arduino with a-gsm shield SD CARD example >> How to run - quick tutorial Arduino with a-gsm shield SD CARD

-          SMS Arduino GSM shield example >> SMS how to run - quick tutorial Arduino with a-gsm shield

-          Arduino gsm shield GPRS HTTP example >> how to run - quick tutorial HTTP / GPRS Arduino with a-gsm shield

-          Arduino gsm shield UTILITIES(SIM/MODEM/NETWORK/POWER ON/POWER OFF) example >> how to run - quick tutorial UTILITIES(SIM/MODEM/NETWORK/POWER ON/POWER OFF) Arduino with a-gsm shield

-          Arduino gsm shield SEND DTMF example >> how to run - quick tutorial SEND DTMF Arduino with a-gsm shield

-          Arduino gsm shield RECEIVE DTMF example >> how to run - quick tutorial RECEIVE DTMF Arduino with a-gsm shield


a-gsm series GSM / GPRS / DTMF / SMS Raspberry PI shield examples # (tar.gz)

Raspberry PI GSM GPRS shield examples list (python - preview, NOT COMPILABLE):

- - a-gsm 2.064 power on / power off / modem communication example >> GSM SHIELD POWER ON/OFF tutorial code

- - a-gsm 2.064 set serial communication speed example >> GSM SHIELD SET SERIAL SPEED tutorial code

- - a-gsm 2.064 list/read SMS example >> GSM SHIELD READ/LIST SMS tutorial code

- - a-gsm 2.064 send SMS example >> GSM SHIELD SEND SMS tutorial code

- - a-gsm 2.064 HTTP client over GPRS example >> GSM SHIELD GPRS over HTTP tutorial code

- - a-gsm 2.064 list/read/write/delete files on uSD example >> GSM SHIELD FILE SYSTEM HANDLING tutorial code

- - a-gsm 2.064 SIM/MODEM/MISCELLANEOUS (including DTMF) usage example utility >> GSM SHIELD UTILITIES tutorial code



a-gsm-raspian-ppp.tar.gz - Raspian PPP and routing utility - change and save a-gsm serial communication speed Python utility (included in a-gsm-raspian-ppp.tar.gz and in a-gsm-series-RaspberyPI-code-examples-1.0.tar.gz)

a-gsm-raspian-ppp-1.0.tar.gz # (tar.gz)

a-gsm series GSM/GPRS shield IoT Rest support for Arduino >> GSM modems IoT Rest support for Arduino # (zip)

Arduino GSM class hack. Run (almost) any project writen for Arduino GSM using the a-gsm shield >>
Arduino GSM class hack for GSM shields (a-gsm and c-uGSM) (zip)


Additional documentation: (click for view, right click + save as for saving on you computer)

kick-start for a-gsm 2.064 by (PDF) READ THIS ONE FIRST!


a-gsm shield RaspberryPI USB communication how to (txt) NEW!

Arduino/RaspberryPI gsm shield communication debug how to (txt) NEW!

a-gsm v 2.064 audio wiring (jpg) NEW!

a-gsm v 2.064 rev 1.3 ARDUINO and RASPERRY PI compatible shield block schematics (png) NEW!

a-gsm series GSM / GPRS / DTMF / SMS ARDUINO and RASPERRY PI compatible shield presentation (PDF) UPDATED!

a-gsm shield series - TOP description (jpg)

a-gsm shield series - ARDUINO wiring using software serial (used in CURRENT Arduino code examples) (txt) UPDATED!

a-gsm shield series - Arduino wiring for hardware serial (txt)

a-gsm shield series - Raspberry PI B+ wiring schema (png)

QUECTEL M85 AT command manual (PDF)


Do not miss the a-gsm shield projects pages (proposed by contributors and by

Arduino & RaspberryPI projects based on a-gsm shield



document version 1.1 / 2020-04-02 © R&D Software Solutions srl