Questions tagged [data]

Data are values of qualitative or quantitative variables, belonging to a set of items

Data are values of qualitative or quantitative variables, belonging to a set of items. Data in computing (or data processing) are represented in a structure, often tabular (represented by rows and columns), a tree (a set of nodes with parent-children relationship) or a graph structure (a set of interconnected nodes). Data are typically the results of measurements and can be visualized using graphs or images. Data as an abstract concept can be viewed as the lowest level of abstraction from which information and then knowledge are derived. Raw data, i.e., unprocessed data, refers to a collection of numbers, characters and is a relative term; data processing commonly occurs by stages, and the "processed data" from one stage may be considered the "raw data" of the next. Field data refers to raw data collected in an uncontrolled in situ environment. Experimental data refers to data generated within the context of a scientific investigation by observation and recording.

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What makes the stack concept useful in embedded programming?

Below is an illustration of the stack concept: I have read many times about the stack pointer and how some variables are stored in SRAM on a stack. Many tutorials explain how it works, but not why this concept exist at all. Imagine I am the program…
GNZ
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How much data could be stored on a standard compact cassette using modern encoding?

My father and I recently dug out his old Commodore 64 from his basement and tried to revive it. Among other accessories, we also found his old Datasette drive, which is essentially a normal tape drive that can be connected to the computer to store…
DLCom
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Why can't Wi-Fi run at 2.4 Gbit/s?

So Wi-Fi runs in the 2.4 GHz band, yeah (and the new ones 5 GHz)? Which means that every second, a Wi-Fi antenna outputs 2.4 billion square wave pulses, right? So I was wondering, why can't it transmit data on every pulse, and be able to send data…
MC ΔT
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Could data transmission power consumption be lessened by transmitting more zeroes?

According to the IEA 250 TWh of power was consumed in 2019 due to data transmission globally, about 1% of worldwide electrical power use. I would like to pose a very simple question regarding power consumption in data transmission. Does it use more…
Fiach Reid
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How could you transfer data over an audio line?

I'd like to pass some data over an audio cable (i.e from audio card to my cellphone) with a short cable. I'm looking for some ideas for algorithms for achieving this. They of course should include the proper modulation technique to transfer the data…
roman
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Data transmission protocol with two lines and no explicit clock

Are there communication protocols that transmit bits using two lines A and B as follows: When line A is toggled, a 0 is sent. When line B is toggled, a 1 is sent. I currently use this to push out debugging info from my µC projects, because is…
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General protocol for data transfer from one system to another?

What is the general protocol to send information from one system to another? For example, let's say we have some information collected from microcontroller over a length of time that we want to send to another microcontroller. I've heard of SPI and…
O_O
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Best way to store very small amount of data?

I'm building a side project at the moment and I want to be able to store and retrieve a very small amount of data (10 kB tops). If the power is disconnected I want to be able to retain the data. I know about EEPROM, however, I noticed there are…
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What is the theoretical maximum data transfer rate of a pair of wires in a phone cable?

Yesterday folks from my ISP came to install a 16 Mbps "Fiber to the Home" connection, but I noticed that the connection still comes in through the same two wires on our phone jack. Could that same connection handle a 25 Mbps connection? What about…
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Flexible-PCBs: what data is needed for manufacturers?

Can someone explain more about how you generate data for flexible or flexi-rigid PCBs for manufacture? Do I just make more layers and export more gerber files? Is there anything I need to keep in mind when sending these to be manufactured? I've made…
kerblogglobel
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Why don't we use 7075 aluminum Ethernet and USB cables?

Since the skin depth of copper at 1Ghz is about 2.3 micrometers, it doesn't seem like aluminum would provide a worse signal to noise ratio. 7075 aluminum is also much more resilient and stronger than pure copper, so it should be able to bend more…
genealogyxie
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Can the Arduino be used to "spy" on a UART connection between two devices?

I have a need to install an Arduino (actually just the IC) into existing hardware to enhance functionality. What I would like to do is connect the Arduino so that it "spys" on the I/O lines between two chips on a board. If the Arduino picks up a…
Brad Hein
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Saving data without a microcontroller?

Is there a way to save voltage data directly (without a microcontroller) to anywhere, like EEPROM, SDCARD, etc.? For example, I am using an MPX pressure sensor which gives 0V to 5V analog output. Instead of converting voltages to pressure in a…
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Avoiding confusion between no input and a zero in binary?

Suppose I'm transmitting data through FM where 0 is 2Hz and 1 is 4Hz. The transmitter is transmitting 2Hz when there is no input. If I fed the recieved binary to a UART port of a microcontroller, how would the microcontroller differentiate between…
Allenph
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Data retention on a microcontroller

Just reading the datasheet of the attiny13 it says that it can hold its data for 20 years at 85 degrees Celsius and 100 years at 25 degrees Celsius. Is this irrespective of the read and writes on the micro for example I turn it off and keep it at a…
Dean
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