47 votes
Accepted

How do GPS satellites refresh their clocks

Clock errors are not corrected, they are compensated in two steps. 1. Error determination The GPS control segment uses reference receivers in well known locations to determine the actual orbital ...
Andreas's user avatar
  • 1,795
20 votes

Is HSYNC required during VSYNC for VGA?

I can't find any trustworthy source of info to decide if VSYNC without HSYNCs will work with all VGA monitors. We only have to find one example that doesn't work to prove the negative, so... I made a ...
Bruce Abbott's user avatar
  • 56.2k
18 votes
Accepted

In one-way asynchronous serial communication, how does the receiver sync up its bytes?

UART timing for asynchronous data relies on knowledge of the data rate and having a clock that is typically 16 x faster. The top half of the picture shows how data is re-synchronised and the bottom ...
Andy aka's user avatar
  • 452k
18 votes
Accepted

Do crystal oscillators synchronize by themselves when coupled by supply voltage?

They can do. When you want oscillators to lock to others like this, it's called 'injection locking', and is a useful but little-known technique. You would apply a bit more signal for injection than ...
Neil_UK's user avatar
  • 165k
18 votes
Accepted

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

The SPI master is not responsible for making sure that the slave's internal state machine gets 'enough' clock pulses. All the master is responsible for is one clock pulse per bit transferred to or ...
brhans's user avatar
  • 14.7k
17 votes

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

The answer to any question about the SPI protocol is: there is no SPI protocol! It's the simplest possible way to transfer serial data, essentially just a shift register. Have a look at a typical SPI ...
awjlogan's user avatar
  • 7,929
16 votes

gps performance for synchronization

A GPS receiver creates a local replica of something called "GPS system time", which is a virtual timebase created from all of the clocks on the satellites and ground stations. This replica is integral ...
Dave Tweed's user avatar
  • 172k
12 votes

Need a method for synchronization of galvanically separated microcontrollers

Question 1: is there a method to do sampling correction/syncronization between the microcontrollers? Can you suggest a literature in this topic? All STM32 ADC are capable of using an external trigger ...
Jeroen3's user avatar
  • 22.8k
10 votes

How does 2-ff synchronizer ensure proper synchonization?

The simple answer is that they don't on their own. The synchroniser is there not to ensure the data gets across, but the ensure you don't end up with metastable signals feeding lots of other signals ...
Tom Carpenter's user avatar
8 votes

Is there an efficient way for synchronising audio events real-time with LEDs using an MCU?

I am not fond of encoding command data as an analog signal in a digital file. I think I would try something like encoding the lighting commands as text blocks in the lyrics block of the ID3 ...
JRE's user avatar
  • 70.9k
8 votes

Is HSYNC required during VSYNC for VGA?

Yes, HSYNC is required. The monitor loses horizontal sync if you stop sending it, regardless of the state of VSYNC. Or, if the receiving thing is not directly a monitor but some chip that samples ...
Justme's user avatar
  • 144k
8 votes
Accepted

Series thyristor circuit

You'll need equalisation for both static and dynamic behaviour. As all of us are aware, the I-V and reverse recovery characteristics of the same brand/model SCRs are similar but not equal due to ...
Rohat Kılıç's user avatar
7 votes
Accepted

How does async data transmission actually work?

For the most common asynchronous serial communications the protocol requires the transmit and receive ends to agree on the data signalling rate and the data format. Format being an agreement between ...
Michael Karas's user avatar
7 votes
Accepted

How are two atomic clocks synchronized?

An "atomic clock" comprises two major subsystems: a precision oscillator controlled by a feedback mechanism that's based on some quantum-mechanical phenomenon, and a digital counter/display subsystem ...
Dave Tweed's user avatar
  • 172k
7 votes

Why do we need to synchronise asynchronous inputs in FSM?

As you already understand, your traffic light controller state machine is a synchronous machine. That is, it is driven by some clock in such a way that all combinatorial logic changes happen and ...
Trevor_G's user avatar
  • 46.6k
7 votes
Accepted

Need a method for synchronization of galvanically separated microcontrollers

Both of these work on the idea that there is at least some delay in the sample loop of the slaves, which could be adjusted to make the slowest slave catch up with the fastest. That is, that there's a ...
jonathanjo's user avatar
  • 13.9k
7 votes

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

SPI is not a protocol in that sense which you mean. It is only an interface to transfer bits automatically in serial fashion, most commonly in multiples of eight to transfer bytes between devices. ...
Justme's user avatar
  • 144k
6 votes

How do GPS satellites refresh their clocks

say you have a clock at location A. How do you synchronize it with a clock at location B, which is far away from A? You can do what NTP does. Roughly speaking, send a request for current time at the ...
Dmitry Grigoryev's user avatar
6 votes

In one-way asynchronous serial communication, how does the receiver sync up its bytes?

UARTs (rs232) have a start bit (0) and a stop bit(1). see Andys diagram. But they use wire, and the noise is very low -basically none. On a noisy link, this works very badly. If the start bit is ...
Henry Crun's user avatar
  • 5,353
6 votes
Accepted

Is there an efficient way for synchronising audio events real-time with LEDs using an MCU?

Using an auxiliary DSP for decompression may make this difficult unless you limit yourself to constant bitrate files - if you need high time accuracy of the light events you may need to account for ...
Chris Stratton's user avatar
6 votes

Is there an efficient way for synchronising audio events real-time with LEDs using an MCU?

I once developed an application in which arbitrary events could be triggered by audio watermarks embedded in the sound. You could play the sound through tinny unamplified computer speakers at one end ...
Dave Tweed's user avatar
  • 172k
6 votes

Need a method for synchronization of galvanically separated microcontrollers

is there a method to do sampling correction/syncronization between the microcontrollers? Can you suggest a literature in this topic? So, you'll need to synchronize their sampling clocks. That ...
Marcus Müller's user avatar
6 votes

Is HSYNC required during VSYNC for VGA?

If you have a receiving decoder you get to do whatever you want: it’s no longer VGA, it’s a digital video link. You could for example produce H sync all the time (with SPI CS, say) and encode the data ...
hacktastical's user avatar
  • 52.8k
6 votes

Series thyristor circuit

I randomly have a Velonex 510 Ring Generator, which uses an SCR stack. Here's an internal view: As you can see, they have a stack of six (optionally seven in another model, it would seem) SCRs in ...
Tim Williams's user avatar
6 votes
Accepted

10MHz reference vs 1 PPS vs GPSDO

A GPSDO is a way of providing a 10MHz reference. A GPSDO can be an external device, but some SDR devices are also able to "host" a GPSDO so that you don't need an external unit in its own ...
hobbs's user avatar
  • 7,330
5 votes

How to synchronize a generator on the electrical grid?

I have done this with multiple 500KVA truck mounted machines on a festival site back in the day, if goes something like this: Set the no load voltage of the two machines to be within a volt or so. ...
Dan Mills's user avatar
  • 17.5k
5 votes
Accepted

Can I use GPS to synchronise two pieces of hardware?

Yes, GPS is used for exactly that purpose pretty often. GPS receivers often emit a sharp pulse-per-second signal. Together with the current GPS or UTC time that you can query through the usual means (...
Marcus Müller's user avatar
4 votes
Accepted

Why is the CAN bus always busy (microcontroller)?

There are usually two causes of this: The bus terminators are not installed. The 120 Ω terminators at each end of the bus perform two functions: Absorb the energy that would otherwise be ...
Olin Lathrop's user avatar
4 votes

gps performance for synchronization

Simply because the system is more than good enough to do what's asked of it. The power is low, but it's enough for a sensitive receiver with a clear view of the sky to reconstruct with high ...
hobbs's user avatar
  • 7,330
4 votes

Are Newfoundland's and Quebec's power grid synchronized

No, the Quebec's grid is isolated from the rest of the North American continent. This is due to the historical decision to make sure that Quebec is 100% independent in terms of energy production. ...
MathieuL's user avatar
  • 1,126

Only top scored, non community-wiki answers of a minimum length are eligible