Double Gate?

[tulamide]

Would it be possible?

What I'm thinking of is a gate that closes when a signal is higher than threshold A, but then stays closed until the signal is lower than threshold B. Since I wouldn't want to use it directly, it should somehow output false for closed and true for opened.

Any examples would be appreciated. And please remember that I am not able to build it myself from scratch. So any advice that's just describing things as text, is well-meant but useless for me. So don't waste your time, if you don't plan to also add a schematic.

Thank you anyway!

[trogluddite]

Sounds like what you need is a "Schmitt Trigger" (a gate with hysteresis). Unfortunately I seem have hit the dreaded "attachment quota" (I said I would jinx myself last time I mentioned it!). Here's a DropBox Link instead (it's the "inverse" version that fits what you described).

[tulamide]

Sounds like what you need is a "Schmitt Trigger" (a gate with hysteresis). Unfortunately I seem have hit the dreaded "attachment quota" (I said I would jinx myself last time I mentioned it!). Here's a DropBox Link instead (it's the "inverse" version that fits what you described).

Thank you very much! Yes, this inverted Schmitt Trigger was exactly what I was looking for! Of course, it's a black box for me, but it doesn't matter, because it works. Awesome!

[adamszabo]

Of course, it's a black box for me

I converted the assembly to Ruby I hope it helps to understand better

Code: Select all

#green float inputs: @in, @lo, @hi

def init
   @gate = false
end

def event(i,v,t)
   @gate = ( @gate || (@in >= @hi) ) && (@in >= @lo)
   output 0, @gate == false
end

[tulamide]

I converted the assembly to Ruby I hope it helps to understand better

Code: Select all

#green float inputs: @in, @lo, @hi

def init
   @gate = false
end

def event(i,v,t)
   @gate = ( @gate || (@in >= @hi) ) && (@in >= @lo)
   output 0, @gate == false
end

It does! You just need to pass the output in parentheses: output 0, (@gate == false)

And it brings up a question
The Schmitt Trigger uses only 8 instructions (wow!), while the inverted one uses 11. In the Ruby version, I can make an inverted Schmitt Trigger just by using 'not': output 0, !(@gate == false)

Is that not possible in fewer than 3 instructions?

[adamszabo]

Is that not possible in fewer than 3 instructions?

I believe you can use the "andnps" (and not) instruction on the normal Schmitt trigger, I dont know how to apply it from the top of my head right now.

[trogluddite]

I think Adam's probably right about the inversion. It's a module I made years ago, and the assembler didn't used to recognise any inverting logic opcodes, so a compare with zero may have been the only way to do it (the pslld get you a zero by bit-shifting all the 1s out of a register - much quicker than loading a zero constant from memory). It might even be possible to refactor it so that the inversion isn't a separate step these days.

[tulamide]

I understand. And it's totally fine. It was no criticism, I was just curious after I understood what's going on, thanks to Adam's Ruby translation.

I'm totally fine with the versions!

Thanks guys

[wlangfor@uoguelph.ca]

I've used schmidt, but have you tried doing it in blue?

You can convert the linear to db using a logarithm and then you output the db you wish to reduce by and send to a Sam Mungall VCA linear db ASM code optimized by Barak.
It saves a percent or two in CPU and is often faster.

Here's a link to My new tools that should help you get there:
http://dsprobotics.com/support/viewtopic.php?f=3&t=38514

Take a look at how I optimized a limiter for ideas?

And BTW, instead of release, why not just use Trog's ASM slide to reduce the db? It's the same as release in most ways. A good idea maybe, anyways, GL.

[tiffy]

I converted the assembly to Ruby I hope it helps to understand better

Code: Select all

#green float inputs: @in, @lo, @hi

def init
   @gate = false
end

def event(i,v,t)
   @gate = ( @gate || (@in >= @hi) ) && (@in >= @lo)
   output 0, @gate == false
end

It does! You just need to pass the output in parentheses: output 0, (@gate == false)

And it brings up a question
The Schmitt Trigger uses only 8 instructions (wow!), while the inverted one uses 11. In the Ruby version, I can make an inverted Schmitt Trigger just by using 'not': output 0, !(@gate == false)

Is that not possible in fewer than 3 instructions?

Hi guys, I wanted to use this Ruby version of the Inverted Schmidt-Trigger connected to a knob as input, however apart from the required Bool pulse it provides at its output it also let through unwanted triggers from the knob. Is there a method in Ruby to completely stop those unwanted triggers coming from the knob to appear at the output of the Schmidt-Trigger? Thanks.