Nokia 3.1 Sim Card Slot

[Eri Pfaff]

Nahum looking at the teardown I do not think that your sim card slot is replaceable. It looks like it is a solid part of the logic board Nokia N8 Teardown my best advise would be to disassemble it and see if you can get the pins straightened out if bend and to see if you can get the mechanism fixed.Of course do NOT do it if your phone is under any kind of warranty. Could be a case for Nokia carepoint. Just my 2 cents....Good Luck

The Lumia 820 comes with only 8GB of internal storage but includes a microSD card slot that can handle up to 32GB worth of data. The 920 already comes with 32GB of storage built in, so Nokia also seems to have felt that an SD card slot was simply not needed.

The new Lumia offers a 4.5-inch PureMotion HD Plus display with a WXGA resolution of 1,280x768 pixels. The ClearBlack display filter is designed to cut down on sun glare. The phone comes with built-in wireless charging that supports the Qi standard, so you can juice it up through any compatible charger.

The camera relies on PureView technology for image stabilization and greater sensitivity to light. Also part of the package is an augmented reality feature known as City Lens, which lets users track down local businesses simply by pointing the phone in a certain direction.

Some mobile phones support use of two SIM cards, described as dual SIM operation. When a second SIM card is installed, the phone may allow users to switch between two separate mobile network services manually, have hardware support for keeping both connections in a "standby" state for automatic switching, or have two transceivers to maintain both network connections at once.

Dual SIM phones are mainstream in many countries where phones are normally sold unlocked. Dual SIMs are popular for separating personal and business calls, in locations where lower prices apply to calls between clients of the same provider, where a single network may lack comprehensive coverage, and for travel across national and regional borders.[1][2] In countries where dual SIM phones are the norm, people who require only one SIM leave the second SIM slot empty. Dual SIM phones usually have two unique IMEI numbers, one for each SIM slot.

Devices that use more than two SIM cards have also been developed and released, notably the LG A290 triple SIM phone,[3] and even handsets that support four SIMs,[4][5] such as the Cherry Mobile Quad Q70.[6]

The first phone to include dual SIM functionality was the Benefon Twin, released by Benefon in 2000.[7] More dual SIM phones were introduced in about 2007, most of them coming from small Chinese firms producing phones using Mediatek systems-on-a-chip. They started to attract mainstream attention.[8][9]

Such phones were initially eschewed by major manufacturers due to potential pressure from telecommunications companies,[10] but from about 2010 Nokia, Samsung, Sony and several others followed suit, with the Nokia C2-00, Nokia C1-00 and Nokia C2-03 and most notably the Nokia X,[11][12][13] phones from Samsung's Duos series,[14] and the Sony Xperia Z3 Dual, Sony Xperia C[15] and tipo dual.[16][17] Apple added dual SIM support in its 2018 iPhone XS models, with models sold in China containing two physical SIM slots, and models sold elsewhere supporting dual SIM by means of (Embedded) eSIM alongside a single physical SIM.[18][19]

For originating communications via the mobile phone network, the way to choose which SIM is used may vary on different phones. For example, one can be selected as primary or default for making calls, and one (which could be the same one) for data. Apple phones supporting dual SIMs can be set up to automatically use a specific SIM for each contact or the same one used for the last call to the contact, for iMessage, and for FaceTime.[20] Typically when dialling or sending a message an option to select a SIM is displayed.

Dual SIM standby phones allow both SIMs to be accessed by using time multiplexing. When one SIM is in active use, for example on a call, the modem locks to it, leaving the other SIM unavailable. Older examples of dual-SIM standby phones include the Samsung Galaxy S Duos,[23] the Sony Xperia M2 Dual,[24] and the iPhone XS, XS Max and iPhone XR.[25]

Dual SIM dual active (DSDA) phones have two transceivers, and can receive calls on both SIM cards, at the cost of increased battery consumption and more complex hardware.[26][27] One example is the HTC Desire 600.[28]

Some telephones have a primary and a secondary SIM slot that support different generations of connectivity. For example, 4G and 3G primary, and 3G and 2G secondary,[29] or 5G and 5G, or 5G and 4G.[30] Selecting either of the SIMs as primary is usually possible without physically swapping the SIMs.

Some phone models utilize a "hybrid" SIM tray, which can hold either two SIM cards, or one SIM card and one MicroSD memory card.[31][32] The Huawei Mate 20 range introduced a proprietary memory card format called Nano Memory, exactly the size and shape of a nano SIM card.[33]

Some devices accept dual SIMs of different form factors. The Xiaomi Redmi Note 4 has a hybrid dual SIM tray that accepts one micro SIM card and one nano SIM card, the latter of which can be swapped for a MicroSD card.[29]

Dual SIM phones have become popular especially with business users[10][34] due to reduced costs by being able to use two different networks, with one possibly for personal use or based on signal strength or cost, without requiring several phones.

Some sub-contract Chinese companies supply inexpensive dual SIM handsets, mainly in Asian countries. The phones, which also usually include touch screen interfaces and other modern features, typically retail for a much lower price than branded models. While some such phones are sold under generic names or are rebadged by smaller companies under their own brand,[9] numerous manufacturers, especially in China, produce phones, including dual SIM models, under counterfeit trademarks such as those of Nokia or Samsung,[35] either as cosmetically-identical clones of the originals, or in completely different designs, with the logo of a notable manufacturer present in order to take advantage of brand recognition or brand image.[8]

Dual SIM phones are common in developing countries, especially in Southeast Asia and the Indian subcontinent, with local firms like Karbonn Mobiles, LYF, Micromax and Cherry Mobile releasing feature phones and smartphones incorporating multiple SIM slots.[36][37]

Dual SIM phones have been rare in countries where phones have been usually sold on contract, as the carriers selling those phones prevent SIMs from competing carriers from being used with the phones. However, dual SIMs have been popular in locations where people normally buy phones directly from manufacturers. In such places there is little lock-in to carrier networks, and the costs of having two phone numbers are much lower.

Dual SIM phones allow separate numbers for personal and business calls on the same handset. Access to multiple networks is useful for people living in places where a single network's coverage may prove inadequate or unreliable. They are also useful in places where lower prices apply to calls between clients of the same provider.[38]

here's my understanding of SPI. i have MOSI and MISO pins, a serial clock pin.. and then the slave select. if i hook up my screen to the arduino directly, i can also hook up the SD card reader to the same pins and have a different slave select pin for that... thus saving some valuable pins in the process. it makes sence.. but i have no idea how to go about doing that.

for anyone that wishes to help... Nokia 3310/5110 LCD tutorial (PCD8544) here's a tutorial for the nokia lcd screen that comes with example code.. and the sd chip library is in the arduino ide already.

can someone write a really basic bare bones code example of using these via SPI together. i honestly have no idea how to do it, but i really do need to save all the pins i can with my current project. (a wristwatch computer terminal) i can show anyone interested the code which includes the circuit and chips included written down. so far, it's an extremely affordable project.

It's important to distinguish between hardware SPI and software SPI. When you're using hardware SPI you're using pins 13, 12, 11, and 10 on the Arduino and the SPI library. If you're using software SPI you're usually using the ShiftOut and Shiftin functions and can use any pins; transfer rates will be much slower.

In general though, the clock (usually called CLK, CK, or SCK) pins are all connected together. The master's data in pin (MISO, master in slave out, hardware pin 12 on the Arduino) is connected to the data out pins (usually DO or SO) on each of the devices. The master's data out pin (MOSI, master out slave in, hardware pin 11) is connected to the data in pins (DI or SI) on the devices. Then as you mentioned each device gets a different connection for the chip select (CS or SS) from the Arduino (hardware pin 10).

The last thing to watch out for is level conversion. Assuming your Arduino is running at 5V you have to make sure that outgoing signals (the Clock, MOSI, and CS pins) are converted to 3.3V before it reaches any of the devices (SD cards and 5110 displays are both 3.3V devices). Incoming 3.3V signals (connected to the Arduino MISO pin) from the devices will still be treated as a digital high value by the 5V Arduino; they don't need to be translated up to 5V. Adafruit's tutorial with the 5110 explains how to do the 5V to 3.3V conversion with a 4050 IC.

Chagrin:
There's nothing too magical other than knowing the various naming schemes of the SPI pins. Explaining the connections would be much simpler if you could provide a link to the exact SD card breakout.

another thing is that the board i'm running is running off of USB right now as i test things. but the batteries i'm using for it power the device up with 3volts i'm building a wrist watch. and i don't want to suck power from the batteries too fast. so i'm making it use a low voltage to begin with. everything seems to be working fine that way for now

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