What is USSD
What is the difference between USSD and SMS
Examples of USSD usage
What about USSD short codes
Requirements
Installation
From PyPI
Useful links
Donation

Published October 1, 2020 © LGPL

Py-SIM800L-USSD

Unstructured Supplementary Service Data (USSD) network result parser with Python language

BeginnerFull instructions provided1 hour4,379

Things used in this project

Hardware components

SIMCom Wireless Solutions SIM800L

Raspberry Pi 4 Model B

SparkFun FTDI Basic Breakout - 3.3V

Software apps and online services

Raspberry Pi Raspbian

Hand tools and fabrication machines

Soldering iron (generic)

Solder Wire, Lead Free

Solder Flux, Rosin Mildly Activated RMA

Premium Female/Female Jumper Wires, 40 x 3" (75mm)

Story

NOTICE: Be prepared to handle huge power consumption with peek up to 2A. Maximum voltage on UART in this module is 2.8V. Higher voltage will kill the module.

Pinout SIM800L

SIM800L is a complete Quad-band GSM/GPRS solution in a SMT type which can be embedded in the customer applications.

SIM800L support Quad-band 850/900/1800/1900MHz, it can transmit Voice, SMS and data information with low power consumption. With tiny size of 15.8*17.8*2.4 mm, it can fit into slim and compact demands of customer design. Featuring Bluetooth and Embedded AT, it allows total cost savings and fast time-to-market for customer applications.

PinoutRaspberryPi

The Raspberry Pi is a low cost, credit-card sized computer that plugs into a computer monitor or TV, and uses a standard keyboard and mouse. It is a capable little device that enables people of all ages to explore computing, and to learn how to program in languages like Scratch and Python. It’s capable of doing everything you’d expect a desktop computer to do, from browsing the internet and playing high-definition video, to making spreadsheets, word-processing, and playing games.

What is USSD?

USSD (Unstructured Supplementary Service Data) is an interactive, menu-based technology communication protocol available on every GSM-enabled mobile device.

It is a session-based text communication without a store-and-forward mechanism (unlike SMS) that is practical for interactive communication, such as banking or education.

USSD messages can have up to 182 alphanumeric characters and the time it takes from a request to a response is 2 seconds while it takes 6 seconds for an SMS to reach a mobile phone.

What is the difference between USSD and SMS?

While SMS is a store and forward technology, USSD texts and interactions are not stored on the mobile phone. SMS content remains stored in the mobile phone memory.

Examples of USSD usage

Some examples of service usage are airtime top-ups, "please call me" services, balance checking and mini statements delivery.

What about USSD short codes?

USSD short code format is defined by the * and # signs at the beginning and the end of the series of digits.

There are three types of USSD short codes available. The standard rate USSD short code is charged the standard fee for the USSD menu usage by the end-user. Reverse-billed short codes are free for the end-user. Premium rate USSD short codes are charging the end user a premium price for short code triggering. Generally, USSD short codes are either reverse-billed or standard rate.

Requirements

Python 2.7 or Python 3.4 and newer
If running on Windows: Windows 7 or newer

Installation

This installs a package that can be used from Python:

import serial

From PyPI

pySerial can be installed from PyPI:

python -m pip install pyserial

Using the python/python3 executable of the desired version (2.7/3.x).

Developers also may be interested to get the source archive, because it

contains examples, tests and the this documentation. By using PyPI, you will be using the latest stable version.

Useful links

Donation

print('If this project help you, you can give me a tip ;) ')

Paypal/mamdpay <<<<<<<<<<<>>>>>>>>>>> Linkedin/MortadhaDahmani

Code

USSDDecode.py

#!/usr/bin/python3
# -*- coding: utf8 -*-

import time
import serial

def USSDDecode():
    rep = phone.read_until('\n').decode('latin1', "replace")
    #print(rep)

    if rep.find("+CUSD: 0") >=0:
        #print("0")
        rep0 = rep[rep.find("+CUSD: ")+len("+CUSD: 0, \""):len(rep)-7]
        try:
            int(rep0, 16)
            #print ('it is hex')
            rep0 = bytes.fromhex(rep0).decode('latin1', "replace")
            rep0 = rep0.replace(chr(00), "")
            #print(rep0)
            rep=rep0
        except ValueError:
            #print ('it is not hex')
            #print(rep0)
            rep=rep0
    elif rep.find("+CUSD: 1") >=0:
        #print("1")
        rep1 = rep[rep.find("+CUSD: ")+len("+CUSD: 1,\""):len(rep)-7]
        try:
            int(rep1, 16)
            #print ('it is hex')
            rep1 = bytes.fromhex(rep1).decode('latin1', "replace")
            rep1 = rep1.replace(chr(00), "")
            #print(rep1)
            rep=rep1
        except ValueError:
            #print ('it is not hex')
            #print(rep1)
            rep=rep1
    elif rep.find("+CUSD: 2") >=0:
        #print("2")
        rep="Not supported by network"
    return rep

phone = serial.Serial("COM14",  115200, timeout=2)
phone.flushInput()
phone.flushOutput()

phone.write(b'AT')
time.sleep(1)

phone.write(b'AT+CFUN=1')
time.sleep(1)

rep = phone.read_until('\n').decode('latin1', "replace")
#print(rep)
try:
    phone.write(b'ATZ\r')
    time.sleep(0.5)
    rep = phone.read_until('\n').decode('latin1', "replace")
    print(rep)
    
    phone.write(b'ATE1\r')
    time.sleep(0.5)
    rep = phone.read_until('\n').decode('latin1', "replace")
    print(rep)
    
    phone.write(b'AT+CUSD=1,"*123#",15\r')
    time.sleep(2)
    print(USSDDecode())
    phone.flush()
    
    phone.write(b'AT+CUSD=1,"*101#",15\r')
    time.sleep(2)
    print(USSDDecode())
    phone.flush()

    phone.write(b'AT+CUSD=1,"*110#",15\r')
    time.sleep(2)
    print(USSDDecode())
    phone.flush()
    
    phone.write(b'AT+CUSD=1,"2"\r')
    time.sleep(2)
    print(USSDDecode())
    phone.flush()
    
    phone.write(b'AT+CUSD=1,"1"\r')
    time.sleep(2)
    print(USSDDecode())
    phone.write(bytes([26]))
    
    phone.flushInput()
    phone.flushOutput()
    time.sleep(.5)

finally:
    phone.close()

'''Revision History

    Initial Release : 25 Mars 2020

License

    Py-SIM800L is distributed under the LGPL version 3 license.
'''

Credits

Mortadha Dahmani

2 projects • 3 followers

I spend most of my time around IoT platforms. I worked for years in the realization and prototyping of projects and PoC

Py-SIM800L-USSD

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

What is USSD?

What is the difference between USSD and SMS?

Examples of USSD usage

What about USSD short codes?

Requirements

Installation

From PyPI

Useful links

Donation

Schematics

UART Connexion

Code

USSDDecode.py

Credits

Mortadha Dahmani

Comments

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Py-SIM800L-USSD

Py-SIM800L-USSD

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

What is USSD?

What is the difference between USSD and SMS?

Examples of USSD usage

What about USSD short codes?

Requirements

Installation

From PyPI

Useful links

Donation

Schematics

UART Connexion

Code

USSDDecode.py

Credits

Mortadha Dahmani

Comments

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