Questions tagged [sim]

A SIM card is a card in a GSM cell phone that tells the network about the phone, e.g. for authorization.

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A6 SIM module keeps resetting

I'm using a SIM A6 module (Goouuu Tech A6, I believe it's the same) to send messages. The problem is, once I plug in a SIM card, it keeps resetting (the green led blinks and kind of interrupts after 3-...
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SIM7600e http get request with version 1.0 instead of 1.1

I'm using Arduino and SIM7600e to send an HTTP GET request to a custom URL but the server is rejecting it because the request is done with HTTP 1.0 instead of 1.1. If I use SIM800 or SIM900 module, ...
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Assisted GPS (AGPS) on SIM7600 module does not work

I recently got a SIM7600G breakout board and wanted to use it with the CGPS functionality for A-GPS. It works with connecting with my SIM to the Internet and all, but when I try to use AT+CGPS=1,3 (UE-...
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Is there something wrong with this SIM card circuit

I have been troubleshooting a SIM card circuit for a few days now but cannot get it to work. The purpose of this circuit is to connect a quectel bg95 to a sim card so that I can connect to my cellular ...
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2 votes
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Would it be possible to use a GSM without a SIM card?

I would like to reduce the footprint of my PCB (a simple IOT GSM impl.). Given a common GSM such as SIM800/868/900l etc. Would it be possible to completely replace the footprint of a SIM card holder (...
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Problem gsm with SIM868E

I am working with sim868e, I have run the serial port and I am sending and receiving commands without any problems. I am using a custom board, designed by myself. When I insert the SIM card, the ...
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How can I program my mcu stm32f103 to transmit and receive data via a server [closed]

hello I am a beginner and my final project is an alarm system, in fact I use a mcu stm32f103 and I want to transmit the data by a GSM module to a base (to access it by a mobile application) and also ...
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Putty won't allow me to type. Can only type the letter 'A'

I connected a SIM7605CE module to the PC (Image shown below). I downloaded and installed all the necessary firmware for the device. I connected the device to a 5V DC power supply and connected it to ...
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Are there regional constraints with the SIMCom modules? (Eg. SIM7605CE/SIM7600CE)

I recently received a SIMCom Module (Model no. SIM7605CE), shown below. The item can be (purchased online as well). The device, much like the ones used with Arduinos (like the SIM800L), is supposed ...
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Do the contacts on a SIM card and card holder always match?

I am trying to choose an SMD SIM card holder for my PCB but while doing so noticed a few inconsistencies for the C1-C8 locations on a product's footprint. It has got me wondering if all SIM cards and ...
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How can I let 2 devices take turns accessing a SIM card?

I need to store data in a sim card using one device, then another device needs to access that data. They do not ever need to use it at the same time. A question was asked about this a few years ago ...
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How do I prepare my SIM card for SIM800L GPRS GSM module?

Im trying to send a SMS message using the SIM800L GPRS GSM module. I know this might sound stupid but, do I need to load my SIM first before it can send SMS message? If possible, can I just pay after ...
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2 answers
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Why RXD text are uncomplete in atmega328 intrupt driven USART?

I have an Atmega328p MCU which is connected to USB port by ch340 chip and I've connected it to GSM module by hardware RX/TX/GND pins. I don't send any command to USB port all commands are send by ...
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Why does the Atmega328 USART get trapped in a loop?

I have an Atmega328 micrprocessor. I connected its RX/TX pins to an SIM808 module and uploaded this code to the processor to communicate with it and send commands: ...
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SIM 800L, I lose signal (+CSQ=0,0) once I insert the SIM card

I have a GSM/GPRS module, SIM800L, and I am facing network difficulties with it. If the SIM card is not inserted, the antenna connects perfectly to the network with ...
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1 vote
1 answer
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What is an epad in SIM MFF2 layout

I found a Kicad model for SIM MFF2 on the web that I wanted to use in my project but I don't know what is EPAD pin and how to connect. EPAD is this central biggest pad on the right image. Does anyone ...
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SIM800L GND pins

I want to create a PCB design for this . In datasheet of SIM800L i found it has many ground pins. datasheet recommend this : My first question : is just using 2 , 43 , 44 and 45 pins enough and i ...
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GSM SIM800C not responding

I'm using Arduino IDE software Arduino Uno board GSM SIM800C BSNL 4g SIM card Interfacing RX (of GSM) to PIN 2 (of Arduino) TX (of GSM) to PIN 3 (of Arduino) GND to GND Power supply For Arduino - ...
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SIM800L microphone problem

I want to feed SIM800L a microphone signal. I found this page in the datasheet and it worked but I need more a sensitive microphone. I want to hear voices in room as much as possible, like a spy bug. ...
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SIM800L rarely responds to commands

I'm trying to get a SIM800L module working with a USB-to-serial adapter using this circuit: simulate this circuit – Schematic created using CircuitLab (All of those resistors are 1000 ohm.) I ...
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1 vote
1 answer
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Sim Card extender Circuit

I am looking for suggestions to solve a Sim card problem. In my system I have a microcotroller interfaced to an Lte mode and this resides in an outdoor elevated position. I would like to put the Sim ...
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3 votes
1 answer
2k views

SIM800 doesn't give GSM location

I have problem to get exact GSM location using SIM800L. I have followed instructions in the manual. But my module just gived me latitude = 0 and longitude = 0. This is what I do with my serial ...
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SIM868 breakout board does not accept GNSS/GPS AT commands

I bought SIM868 breakout board with GNSS support. https://www.aliexpress.com/item/33013782111.html However, I can’t get coordinates using standard at-command AT+CGNSPWR=1, AT+CGNSTST=1, etc. I get “+...
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How to cut a nano SIM out of a 8-pin SIM? [closed]

I have a 8-pin SIM, which I want to cut into a nano SIM (which only has 6 pins). Looking at the Wikipedia X-Ray image, I assume I should cut the lower 2 pins. Is this correct?
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Molex 5039600695: What is the SIM card stopper referring to?

On some SIM card holder datasheets, I've seen references to a card stopper feature that prevents users from inserting a SIM card incorrectly. This card stopper appears to be a mechanical feature built ...
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1 answer
237 views

SIM800: AT-command to get connected sender ids

I want to roughly estimate where my Arduino currently is. For this, I want to fetch the identification numbers of the stations it is currently connected to, so I can put them into an API which then ...
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3 votes
1 answer
855 views

How does a cellular network deal with a duplicate SIM? [closed]

I was pointed here from WorldBuilding. Say I had a cellphone, let's call it cellphone A, and made a perfect copy of it - SIM card and all - and let's call this one cellphone B. If I were to call ...
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How does GSM Module store incoming SMS in its "SM" or "ME" memory?

I am using AI Thinker A7 GSM/GPRS/GPS Module demo v7.1.(The Rx, TX, GND pins of this module are connected to tx, rx, gnd pins of the prolific Rs232-TTL converter and a virtual com port is open in ...
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0 votes
1 answer
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SIM to RJ: emulating SIM card as a RJ connector [closed]

i recently got in a Goodwill store one of the 2500 model phones https://en.wikipedia.org/wiki/Model_500_telephone#Model_2500 and i want to use it. the problem is that i don't have a phone line in my ...
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What could be done with a deactivated SIM card?

I was reading https://reverseengineering.stackexchange.com/questions/15011/how-does-a-sim-card-work and from that, I can say that, really really simply put, a SIM card is sort of an extra memory that ...
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SIM800C - CME ERROR: 15 SIM wrong & CME ERROR: 10 SIM not inserted

I am making a GSM Tracker with SIM800C module. After deploying it into vehicles.. It works fine.. but after some days, it starts responding as CME ERROR: 15 SIM wrong for command AT+CPIN? & CME ...
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4 votes
1 answer
511 views

M2M vs normal SIM cards

I recently bought some global 3G modules from Digi International and wanted to test one of them with the SIM card from my phone. I was surprised when I saw the module couldn't connect to the network....
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2 answers
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SIM800L restart automatically

I know there is a similar question but it did not solve my doubts, I will be clear and concise. I recently bought the SIM800L module and then I started to try it, at the beginning it restarted itself ...
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Connect SIM5360 AWS server GET / POST calls

I have a SIM5360 module, with a Vodafone card, and I would like to connect to some web services, to send and receive data in JSON format, which I have implemented on an AWS server. To execute the AT ...
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1 vote
1 answer
290 views

smart card clocking using NXP

In my current project, I'm trying to implement a smart card reader using LPC1788 which has a built-in smart card interface. Smart cards use the ISO7816-3 standard to communicate with the outside world....
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1 answer
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Power consumption of TDA8029 USIM controller for 3V/5V cards

we are using TDA8029 in one of our application board. Just a summary of the circuit. TDA8029 in our board connects a USIM card and reads the data and sends on UART. In our board, 2 supply inputs of ...
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1 vote
2 answers
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SIM7100 GSM Modem Unreliable Connection

I am trying to communicate with SIM7100 GSM modem but I could just rarely communicate with it across UART interface. I am observing the signal with an oscilloscope, I am giving 5V as High and 0V as ...
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3 votes
1 answer
402 views

Save data on sim card using micro-controller

SIM cards come in various data capacities, from 8 KB to at least 256 KB. All allow a maximum of 250 contacts to be stored on the SIM, Is it possible to save data (other then contacts) in sim card, ...
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I only hear quzz when making a phone call using SIM800L module

I made a board to make a phone call using SIM800L module. A PIC16F886 does the main roles, a PIC12F683 plays an audio message from a 24C256 EEPROM using PWM and sends it to SIM800L. The audio message ...
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2 answers
823 views

What exactly is a SIM card?

Does a SIM card consist of only Flash memory or is there a microprocessor inside as well?
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1 vote
1 answer
711 views

One SIM card shared between two devices - IC? [closed]

i have a GSM breakout board and a 4g dongle. I'm curious whether it is possible to share one SIM card between both of them? Does anyone know if there is any IC available to do this? edit: Only one ...
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sim808 GNSS location update

I'm working on a project in which I have to get current location at every 10 sec interval. I've used sim808 (GSM/GPRS & GNSS) using which I execute AT+CGNSINF command to get the location. I get ...
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1 vote
3 answers
2k views

how can i switch sim card clock signal line betweem two sim cards?

My setup is as on png above, I am using sim800L gsm module, by trial and error i discovered that i can connect sim pins: (rst,gnd,io and clk) and the module detects and connect to GSM without ...
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2 votes
6 answers
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SIM800 PWRKEY - Automatic start

I need to do when the module have connected power supply, it will automatically turn on the module. Because is there a PWRKEY button, probably grounding it or give on that pin VDD_EXT will not work. I'...
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1 vote
2 answers
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SIM card power supply design, from 3V/50mA into 2.7V/10..100mA

I am designing a SIM card with RF radio included. The radio with its CPU needs minimum 2.7V to run. The current consumption is my problem: - for a period of 50msec (during transmission), it requires ...
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1 vote
1 answer
2k views

Smart Card (SIM) clocking requirements

I'm trying to implement a SIM card interface using TI TM4C123XL. I have a question about a clock. TI MCU seems to provide possibility to interface smart cards but don't let me multiply clock without ...
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0 votes
1 answer
502 views

GSM Data Post Over the GPRS Using GSM Modem [closed]

I'm using GSM Modem To post the data over the GPRS for specific website. when i'm posting the data using VODAFONE IN (APN: www) Sim card it pos the data in i'm recieved HTTP 200 ok Response But ...
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1 vote
1 answer
5k views

PWM signal to SIM800 MIC noise reduction

I have an audio signal made by a PIC microcontroller using 20KHz PWM (it passes through a low-pass filter). It is very clear on an 8ohm speaker, but when I connect the output to the MIC inputs of ...
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Why do some GPS devices require a GSM SIM-card?

Why do GPS products like [Image A] always require a GSM (or similar; i.e. 3G, 4G, etc.) SIM-card?; Whereas typical in-car GPS navigation devices, etc. like [Image B] don't? [Image A] [Image B]
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sim card power consumption [closed]

I am trying to calculate the power consumption of a SIM card. I found some SIM card working between 1.65V and 3.3V, but I did't succeed to find information about the current they draw. Does anybody ...
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