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14

Possible reasons I can think of: the card detection switch switches from Vcc instead of ground, so that the logic is inverted and a falling edge becomes a rising edge and vice versa. there's contact bounce, generating both types of edges. Solved with an RC filter.


8

I would put them in. The ESD test involves putting the discharge probe near all the points that you can physically access and seeing if your device can handle the electric field generated. Looking at the sim-card holder design it appears that it would be impossible to direct the charge/field directly onto one of the internal pins given the large metal frame ...


6

The ETSI standard ETSI TS 102 221 describes the procedure for switching (and thus finding the appropriate) supply voltage in section 6.2: 6.2 Supply voltage switching The terminal shall initially activate the UICC with the lowest voltage class available. If no ATR is received, the UICC shall be deactivated and activated with the next higher class, ...


5

Because the first is a GPS tracker that you can call and it replies via IVR or SMS or has a data connection so you can see it online or periodic emails. Maybe automatic geo fencing warnings. The second is not, it's a full blown computer with a high quality GPS system with maps built in and no need for a data or voice connection. As @Eugene had commented ...


4

That is an excellent guide and seems to cover the relevant points well. After having read the guide, why do you think that you can cut corners and use simply interconnected pins? It MAY in fact be possible in practice, but it is not obvious that it would be safe or reliable (even though it may be :-) ). Joining the pins from two SIMS together and powering ...


4

Okay, I was heading down dead ends there. The vendor just confirmed that there is a fault with the SIM card holder on the board.


4

You said "My PC and softwares i used to read/write data from/to sim-card could't recognize my sim-card reader" What did you expect? It is a very simple terminal circuit using a RS232 interface to send and receive data. There is nothing to recognize, e.g. no reader ID... Another thing you have to consider: the data line is bi-directional, i.e. there is one ...


4

The miniaturization of electronics is a process and takes time to refine a design, as well as manufacturing processes that physically create the electronic device, down to their most efficient state. At the time of its inception, the SIM card used an internal chip that was a specific size. As the design of the chip was refined, the SIM card no longer ...


4

Would it be easy/possible given that the IO line needs to be bi-directional? Possible? Yes. Easy? Not so. You would have to detect the direction within the CPLD and switch the pins between input and output accordingly. It is a lot easier to just use an analog multiplexer chip like the 74HC4051 and control the address bits from a CPLD or microprocessor. ...


4

It definitely is a microcontroller since it integrates a microprocessor, RAM memory, persistant memory, timers, I/O (7816 and optionally SPI, SWP, USB), security features and - often - a cryptoprocessor (DES, AES, ECC, RSA, hash). So both are correct: it uses a microcontroller, it uses a microprocessor. The applicable ISO standard is 7816 for smart cards. ...


4

A SIM Card is closer to a microcontroller than a microprocessor as it has all the required logic blocks including memory etc. It differs from a microcontroller because it is a dedicated application circuit specifically designed with the security implications in mind. It is not a general purpose circuit like a microcontroller that can be used in many ...


4

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. Normally, your SIM card would be impossible to clone (it contains a secret that can't be read, but is used by the processor in the SIM card to en- and decrypt specific things, which doesn't allow you to "get" that secret)....


3

That depends on the mode and class the SIM is operated at. The electrical characteristics are defined in the ETSI TS 102 221. You'll find a copy online. Class-A (4.5V to 5.5V) you have: 200µA in idle-state 200mA during operation Class-B operation: (2.7V to 3.3V supply): 200µA in idle state 60mA during operation. Class-C operation: ...


3

Is your intention to pass ESD immunity tests, or make a product resilient to reality? I don't see the distinction that just because the case might only be opened a few times in its life (to change SIM card) that your ESD-risk-per-human-touch-event is any lower, and that this therefore discounts the need for ESD protection. Keep in mind that creepage ...


3

All 6 pin or 8 pin have the SIMs have same functions. At first we need to understand SIM Pinouts; 6 pin includes VCC, GND, I/O, VPP, RST, CLK 8 pin includes VCC, GND, I/O, VPP, RST, CLK, SIM_PRESENCE, GND VCC is supply pin, GND is common ground pin, CLK is Clock pin, RST is Reset Pin and I/O pin is for Data transmission. The only difference between ...


3

First, everything is specified in ISO7816-3. You should really read it (I won't provide any links because the standard is not free, but you can still easily find it on the web). Now, regarding your specific questions: Yes, you need to generate the clock that will be applied to the CLK pin. This clock does not need to be accurate. There is, however, a ...


3

It's not possible to share one SIM between two devices. Well, not easily, anyway. The SIM contains a microcontroller and there is quite a complex communication protocol between it and the device it's installed in that would be confused by connecting two devices to the same SIM. That's in addition to the fact that the two devices would often be trying to ...


3

There is no physical/electrical difference between the SIM cards. It is the economics of the network provider. When a device connects to a cellular network it provides its IMEI (serial number of the device/modem) and IMSI ("number of the SIM card"). Each manufacturer has its range of IMEI numbers, so you can distinguish Simcom, Telit, Quectel, Samsung, ...


3

The phrase "card stopper" is being used in two different ways here. In the top drawing, it's referring to a leaf spring that only gets lifted up out of the way if the beveled corner of the SIM card is in the correct orientation. When a card is inserted incorrectly, it stops the card about halfway in. The small plastic post highlighted in green helps to ...


2

After applying power to the SIM card you must first supply a clock to the clk pin. Use something in the 3-3.5MHz range. Then pull the reset pin of the SIM card low for about 100ms, drive the reset pin high again, and listen to the I/O line for the ATR. It should come in at your clock frequency / 372 or something like that. The baud should be somewhere just ...


2

As soon as you have different power voltages for the SIMs (or power at one SIM and no power at the other SIM) you can not share any data, clock or reset lines, because protection diodes inside the SIM will shorten data, clock or reset signals to the lower power voltage of one of the SIMs. It might be possible to share power, clock and data lines but use ...


2

literal answer The "SIM Reader" and a few wires appears to be all the hardware needed to interface a SIM card to an Arduino. There seem to be some Python scripts designed to talk to it over a serial port; perhaps you wouldn't find it too difficult to translate to something (C++) that runs on an Arduino. Or should I just buy an ordinary smart card ...? "...


2

The SIM800 has a microphone input. The signal you are getting from the microcontroller will be at too high a level for that input. The SIM800 expects an electret microphone, so maybe 100mV signal level. You need to lower the output level from the PIC-PWM. The following circuit provides a lower cutoff (3KHz instead of the 4.8kHz from your circuit) and ...


2

SIM cards are UICCs, which integrate a CPU, memory, and I/O on a single device. The relevant reference is ETSI TR 102 216. ETSI - Smart Cards


2

A few manufacturers are now making SIM on chip parts, sometimes known as MIM (Machine Identification Modules). Have a look at http://www.gemalto.com/m2m/solutions/mim


2

There isn't much information in your question, but I'll explain one common way you can solve this type of problem. In short: You need to get more troubleshooting data, and then use your critical thinking skills to find the cause of the problem by using that data. Remember that responses like "HTTP 400 Bad Request" come from the HTTP server. Therefore you ...


2

I found this battery which should have enough capacitance and ESR is ≤ 650 mΩ http://www.powerstream.com/thin-lithium-ion.htm 2x12x12.5 mm is too big but there is hope you may find one that fits your package. But it may have to be current limited for charging so as not to pull down your 50mA supply voltage.


2

To automate the startup of sim800/sim900 module just keep the pwrkey shorted to ground always. As the supply will be provided modem will be on.


2

Absolutely. Except I am not sure if you are referring to smart cards or mobile specific SIM cards. Smart Cards are easy. They are like any other memory device. If you need to access a SIM card from a mobile phone it can get a bit more difficult as it becomes carrier and phone vendor specific. For mobile SIM cards, I found it easiest to use a GMS modem ...


2

I have found the problem, and may now give the answer to my own question. The optocoupler is broken, hence I removed it and Voila!


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