Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [protocol]

A protocol is a ruleset for formatting and exchanging messages.

285 questions
53
votes
2 answers

Why are USB devices slower than 480 MBit/s

Motivation With a signaling rate of 480 MBit/s USB 2.0 devices should be able to transmit data with up to 60 MB/s. However today's devices seem to be limited to 30-42 MB/s while reading [Wiki:USB]. That is a 30 percent overhead. USB 2.0 has been a…
Chris
  • 671
  • 1
  • 6
  • 7
34
votes
1 answer

How do volume control headphones work?

A recent question over on Android Enthusiasts got me to wondering how volume control headphones work. I don't mean volume control which works by attenuating the incoming signal, but the kind of volume control that signals to the device to increase…
Mark Booth
  • 1,635
  • 3
  • 24
  • 45
30
votes
6 answers

Serial protocol delimiting/synchronization techniques

As asynchronous serial communication is widely spread among electronic devices even nowadays, I believe many of us have encountered such a question from time to time. Consider an electronic device D and a computer PC connected with serial line…
Eugene Sh.
  • 9,986
  • 2
  • 26
  • 41
29
votes
8 answers

When should one switch from ASCII to advanced serial protocols?

All my microcontroller devices that communicate with the PC via UART use ASCII strings for sending commands and receiving data (as implemented in Arduino). That's what I learned when I began digging into electronics and I always found sending bare…
I have no idea what I'm doing
  • 1,361
  • 2
  • 16
  • 25
23
votes
7 answers

Why I2C designed to work with pull-up resistors and not pull-down ones?

I understand that in I2C, SCL and SDA lines use pull-up resistors and the pin drivers are open collector NPN devices which can drive pins to ground. This gives I2C an advantage that the same bus now can be shared with multiple slaves, and even if…
Ashutosh
  • 798
  • 1
  • 5
  • 15
15
votes
1 answer

Official GPS protocol documentation?

Searching for "GPS protocol" reveals many sources for processed GPS data, e.g. NMEA or binary outputs of GPS units. Where is the official documentation for the GPS satellite - receiver protocol? Or any interesting supplemental material that might…
Mark Harrison
  • 10,419
  • 27
  • 68
  • 95
13
votes
2 answers

Rolling Code Explanation

Could somebody explain how rolling code protocols such as KeeLoq work? I understand the basic premise that they use a different code each time so you can't just use replay attack, but I don't understand how one side verifies the correct code etc.…
NickHalden
  • 4,167
  • 3
  • 31
  • 40
13
votes
6 answers

What is the difference between Ethernet and Serial communication?

All the mouse movements, USB connections and other PC peripherals such as printers etc. are what is called serial communication. One bit per time. So far so good. But when it comes to TCP protocol, Ethernet and internet it is not called serial…
user16307
  • 11,802
  • 51
  • 173
  • 312
13
votes
4 answers

LVDS vs MIPI, what's the difference?

What are the practical differences between LVDS and MIPI? A little background information: I am attempting to build my own projector on the cheap and want to use a nexus 10 LCD panel (2560 X 1600 resolution) but I have been reading mixed…
Craig Lafferty
  • 455
  • 2
  • 4
  • 8
12
votes
6 answers

Good RS232-based Protocols for Embedded to Computer Communication

I'm working on a project that involves a good bit of data communication between a remote Arduino and a computer. The wireless connection is through a pair of XBees, so we have a RS232 link between the Arduino and the computer. For small amounts of…
Computerish
  • 717
  • 2
  • 9
  • 18
12
votes
8 answers

What is the name of the protocol(s) used to let an automatic garage door opener know which button I've pushed on the wall control panel?

The wired wall control panel in my garage has only 2 wires connected to it. Yet somehow it acts different when I push the big "door" button than when I push the "light" button or the "lock" button. That pair of wires is connected to the overhead…
davidcary
  • 17,426
  • 11
  • 66
  • 115
12
votes
1 answer

Transceivers in the field of FPGAs: When and why will we use them?

I am recently getting myself into the field of FPGA design and development, and lately I've found myself hearing a lot about transceivers. I tried searching the net for some answers about these components and learn their role in the world of FPGAs…
Itamar
  • 221
  • 2
  • 3
10
votes
2 answers

VHDL: receive module randomly fails when counting bits

Background This is a personal project; it regards connecting an FPGA to a N64, the byte values that the FPGA receives are then sent through UART to my computer. It actually functions pretty well! At random times unfortunately, the device will fail,…
Nick Williams
  • 1,815
  • 3
  • 17
  • 29
10
votes
4 answers

Does the SPI protocol specify how many clock pulses a master device should send to the slave?

I'm trying to implement an SPI device in Verilog. I'm having a lot of problems for coordinating master and slave, since sometimes (with my current impl.) the SPI master device doesn't send enough clock pulses to the slave so it can finish its…
Martel
  • 1,213
  • 6
  • 20
10
votes
2 answers

How do universal IR remote "codes" work?

It is easy to find this kind of reference when searching for IR protocols and codes for specific equipment. The actual IR transmission contains far more data than these small codes can hold. What exactly do these codes represent? How can four digits…
Filipe Nicoli
  • 838
  • 7
  • 13
1
2 3
…
18 19