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.

321 questions
34
votes
14 answers

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
  • 1,559
  • 4
  • 25
  • 52
29
votes
10 answers

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
  • 507
  • 5
  • 12
28
votes
4 answers

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
  • 401
  • 3
  • 6
24
votes
6 answers

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
  • 357
  • 2
  • 4
19
votes
4 answers

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
  • 409
  • 2
  • 5
  • 9
18
votes
7 answers

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
  • 595
  • 2
  • 6
  • 16
13
votes
9 answers

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…
13
votes
3 answers

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…
Fletcher Tomalty
  • 131
  • 1
  • 1
  • 4
11
votes
6 answers

Is it necessary to separate DC power cables and data cables?

I have had this discussion with my colleague earlier. A DC power supply is non-alternating, so the magnetic field a DC power wire generates is constant (is it?). Now, I know the rule is to separate power cables and data cables, but I'm assuming…
Shibalicious
  • 671
  • 1
  • 7
  • 20
11
votes
3 answers

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
  • 1,042
  • 3
  • 13
  • 18
11
votes
8 answers

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…
11
votes
3 answers

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
  • 283
  • 4
  • 9
11
votes
5 answers

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
  • 233
  • 1
  • 6
10
votes
1 answer

Basic protection for USB interface

I have never protected my USB interfaces for microcontrollers until a USB port of my PC stopped working because of a bad connection aparently. So I'm starting to protect them but I found some ESD IC's that protect them but my question is... Is there…
Sein Oxygen
  • 489
  • 1
  • 4
  • 14
10
votes
4 answers

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
  • 707
  • 3
  • 12
  • 32
1
2 3
21 22