GPIO set-reset in 50 ns

I see here folk offering you advice on a 50 uS delay saying you can use an Arduino etc how ever you are asking for a 50ns delay this is like 1000 times shorter.

Are you sure you require 50ns?? If so then the other solutions simply won't do as 50 ns is actually less than 1 clock period on say an Arduino

If you need to do some computation  on an input and get an out put in say 50 ns then I would suggest a controller with a clock speed of several 100's of MHZ to have

a chance of getting the job done. I would actually suggest you get an XMOS Startkit from E14/Farnell and then you will get your 50ns quite easily !

With regards to doing this with RPI as folk have alluded to it may be possible in assembler to get the right delay but because you are using a non realtime O/S your code will be randomly interupted by that OS so your delays can easily be way off. To be honest you need to tell the community more about what you are trying to do to get better answers.

You are right I did not saw he was talking about nano-seconds.

There is no Atmega capable of running even near to that speed.

The project he is into is this one Raspberry Pi with WS2812b strips

This was what got me confused because for that project he was talking about a refresh rate of 50Hz, so I did not digged further on what he was trying to do.

I don't know how he somewhat got into this math he would need a signal in the nanoseconds range.

Anyway there is also the problem of the 1080Amps/5.4KW  Peter calculated was required to drive his project, so I guess he will need to go for some good hardware to have a 1080Amps of current pulsing with a signal in the nanoseconds range.

In that kind of timing even the signal velocity must be taken into account, because the signal would need some time to get to  the end of the 300 meters of led strips.

So I'm sorry, but I got utterly confused with this project.

You are right I did not saw he was talking about nano-seconds.

There is no Atmega capable of running even near to that speed.

The project he is into is this one Raspberry Pi with WS2812b strips

This was what got me confused because for that project he was talking about a refresh rate of 50Hz, so I did not digged further on what he was trying to do.

I don't know how he somewhat got into this math he would need a signal in the nanoseconds range.

Anyway there is also the problem of the 1080Amps/5.4KW  Peter calculated was required to drive his project, so I guess he will need to go for some good hardware to have a 1080Amps of current pulsing with a signal in the nanoseconds range.

In that kind of timing even the signal velocity must be taken into account, because the signal would need some time to get to  the end of the 300 meters of led strips.

So I'm sorry, but I got utterly confused with this project.

May be that confusion came from the Adafruit page for those led strips.

http://www.adafruit.com/products/1138

• Second, to get high density, the controller chip is inside the LED, which is kind of cool, but also means that the chip only uses a single pin for input and a single pin for output. The protocol used is very very timing-specific and can only be controlled by microcontrollers with highly repeatable 100nS timing precision. We have example code for using with the Arduino Uno/Mega microcontroller at 8MHz and 16MHz, but it will not work with the Raspberry Pi, Basic Stamp, NETduino, any other interpreted/virtual machine microprocessor or any processor slower than 8 MHz. For those processors, check our 32 LED/meter digital LED strip which has SPI-like input/output and works well with Pi, NETduino, and other processors.

I guess they got the unit wrong because I would like to see that library with an 8Mhz device, giving a clock signal of 1/100,000,000,000 sec.

... or may be I am getting it all wrong again ... bed time I guess.

Um are we having some type of language fail here. Many of those strips are like 60 LEDs per M and 5 M long giving 300 LEDs per strip.

So the question here is he driving a number of "300 LED long Strips" or 300x strips !!

I find strips like this tend to take 1-2Amps per Metre depending on the colour and Brightness etc so each strip can be 5-10A quite easily.

Unfortunately we are seeing more and more project ideas with poorly fleshed out specs so the advice is equally vague or poor.

Can Parag explain his project and give exact numbers