Questions tagged [gsm]
GSM stands for Groupe Spécial Mobile. It is a standard set developed by the European Telecommunications Standards Institute (ETSI) to describe protocols for second generation (2G) digital cellular networks used by mobile phones.
24 questions
32
votes
7answers
22k views
Why does GSM cause speakers to buzz?
Based on numerous internet resources, speaker wire acts like an antenna which picks up the transmitted signal of nearby cellphones and causes the speakers to buzz. But I'm not really buying that... A ...
7
votes
4answers
1k views
Can Cellphones be used for Ad Hoc Communication?
Can Cell Phones be (legally) used Adhoc, (ie, Point-to-Point) Communication? For example, let's say I'm in a remote area of the woods, or a valley. Can I configure cell phones to be used as true ...
6
votes
4answers
16k views
How to properly power sim800l module?
I have this sim800L module It has a 3.7v - 4.2v voltage requirement. So I created a simple buck regulator using MIC4576 regulator according to it's schematics and adjusted it's output to 4.2 volts. ...
3
votes
4answers
17k views
how much power is radiated by cell towers?
I want to know how much power is radiated by cell towers of GSM (1.8 Ghz), 3G (2.1 Ghz), 4G (2.6 Ghz) ? I want links to references if exist.
13
votes
6answers
3k views
Simulate bad cell phone reception in the lab
I'm currently developing an internet of things device that utilizes a uBlox SARA-U260 gsm/3G modem. In field testing, we have had significant software/firmware issues due to poor cell phone reception ...
8
votes
1answer
2k views
Killing GSM Buzz with Ferrite Beads
I'm trying to rid my speakers of the typical buzz from my iPhone. I get poor reception in my apartment and so it's constantly trying to find a signal, meaning I get a near-constant buzzing when the ...
8
votes
2answers
2k views
Wavelengths blocked by a certain metal mesh
Introduction: I've heard about a theory, according to which you can check if there is any leakage in your microwave oven by putting your mobile phone inside and call it. However, I gave it a try and ...
2
votes
0answers
396 views
GSM noise from a 2-layer PCB with SIM800C
I've designed a 2-layer PCB that contains a 12-5V buck converter (P2576L-50 - a Clone of the LM2576), 3.3 (AP1117-33) and 4V (MIC29302WU) shunt regulators, an STM32 micro and a SIM800C GSM module. ...
1
vote
1answer
733 views
Usb 3 g, 4 g调制解调器,吃晚饭ply
I have read that usually a gsm module requires a power supply capable to provide up to 2A. But how can 3g modems sticks work properly when they are powered through usb port which provides only up to ...
2
votes
3answers
3k views
Is it possible to use SIM900 GPIO to control relays without using external MCU?
From the product manual / reference guide it looks like SIM900 / SIM900A is already equipped with 12 GPIOs. But could not find information on how to use these GPIOs to control relays directly, instead ...
1
vote
2answers
22k views
Connecting GSM SIM900A module with Ardunio
I have bought an SIM900A Mini V4 GSM module. Here is the module, I want to configure with arduino to send and receive SMS. Do I have to connect TXD of this module--Tx of Arduino & RXD of this ...
12
votes
10answers
59k views
What AT command should be sent to modem to get time?
I am using SIM800E. I want to know what AT command should be sent to the modem to get time? This modem has a RTC. But I need to set it automatically through cell tower. The tower can send the time to ...
3
votes
5answers
7k views
How to power a GSM Modem from a Li-Po battery?
I want to integrate an AirPrime SL6087 GSM modem into a design, this is my first try at working with a GSM module. The datasheet states that the modem draws 2A for 1mS every 4mS (max) at 3.6V, the ...
1
vote
2answers
2k views
GSM/GPRS AT command - hitting a link
I am trying to target a specific page (script) on my webserver using a GPRS modem. I can hit my domain, and get a reply back but then when I am trying to call my script it just won't let me: ...
4
votes
1answer
5k views
GSM Module gets into reboot loop
I have assembled a diy m590e gsm gprs module kit, bought from Amazon. The seller provided image is: The Schematic used to assemble the kit is: I connected it to the Laptop using a CP2102 based USB ...
