LOOK WHAT I MADE!!!
And that’s why we use pulldown resistors kids! To limit the aura of the user, ofc
i know my aura is to high 😎
But seriously how to fix this?
Afaik this is because you act as a large antenna, the water in your body acts as a capacitor with circuits, which can make sensitive components(high gain transistors, like in the chip) recive enough power to trigger. Attach a large resistor(~10k) from the inputs to ground(or v+, depending on which is the off state), that way any stray energy gets bled into the supply rails instead of through the chip. When you supply real power, the resistance is lower through the circuit than the pull up/down resistor, so all it does is influence the state when in high impedence(no connections)
Long story short, use a large resistor to slightly bias the inputs to one side, so that they don’t change due to the environment(you)
I just want to say that you explained that extremely well. I’m still learning and very much new to this stuff and your comment was, in my opinion, perfectly balanced in knowledge vs communicating the points. I’m not sure if you’re an educator, but if not, you have a backup career I think lol
Imo it was a poorly written word brick, but ig if you understood then it’s good enough
OP just showed why old computer speakers would warn you before the phone call came through.
Wait, really? I always wondered that but never looked it up. I remember my speakers making noise as a text message was coming in too. I always wondered why it was only when whoever was close to it was getting one. Surely the cell tower has to send the info in all directions for every user in the area to get their texts right? It’s not like it points the antenna at me or anything. But then why don’t I get interference when my neighbor is getting a text?
Crazy to think this was so well known it was implemented into things like GTA IV. The car radio always has interference before getting a call.
Pulldown resistor
Don’t leave floating inputs.Digital electronics works with 0s and 1s and you basically told the circuit “take a guess”.
That’s actually pretty normal for a 74HC00. The inputs are CMOS and very high impedance, so if you leave them floating they basically act like tiny antennas. Your hand getting close can capacitively couple enough noise into the input to make it switch. Try putting a ~10k pull-up or pull-down on the inputs, or just tie unused inputs directly to a defined logic level. Also throw a 100nF ceramic cap right across VCC and GND close to the IC, good practice with logic chips in general. So no, you’re not the problem. You basically built a very crude proximity sensor by accident lol
so technically i could make a proximity-triggered missile with this? i think i am on the right path.
Practically yeah, you’re like three bad decisions away from a proximity fuse
well tell me those decisions so i avoid em ofc.
Well for one you’ll want to have a system that’s intended to work as a proximity sensor instead of one that just accidentally works as one. For large metal objects, an inductive sensor would probably be reasonable. You basically just make a wire loop and pass a reasonable high frequency through it. That causes an induced current in nearby metal objects that, due to conservation of energy and some electromagnetic black magic, causes a measurable change in the impedance of the loop. All you need is a way to measure the impedance and you’re golden. Car sensors at stop lights usually do the same thing. If you look closely you can sometimes see marks in the pavement where they ran the wires to form the sensing loop
Once
I know less about electronics than you probably, but I do know that such behavior is usually correlated to some floating pin. Meaning it has no set upper or higher voltage and thus interacts with the voltage potential of your hand and regulated accordingly. You need somewhere on your chip a pull-up or pulldown resistor.
bruh i started like a month or two ago. but thanks will try.
It can sense your aura
every floating input is a touch sensor if you’re brave enough
Hook a speaker up to it and make a theramin!
First thing I thought of! but that’s probably pure DC - there’ll need to be a simple oscillator and some filtering likely, plus an amp. But that is a lot of juice for lighting an LED!
How to reliably make this exact effect on purpose?
It’s like a hall sensor but for man meat. Maybe IR could work but idk.
There was a video the other day of some welding leads dancing and the top comment said it was cause he was gouging with air. The air doesn’t run the length of the cables. So much current running through the coiled cables had them dancing. Coolest thing I ever saw.
Theremin
You’re a wizard capacitor, Harry!
its because you have floating pins. just like with arduino, you need resistors on your inputs to keep pins from floating.
Floating input
You made a crude capacitive proximity/touch sensor. Cool!
wow this is so awesome!!! 😄🙌
Take this as a lesson to read the datasheet. All you do is google “SN74hc00N datasheet” and a few different sites will pop up. I usually go to TI’s
https://www.ti.com/lit/ds/symlink/sn74hc00.pdf
You will get to the part that says:
“Do not leave standard CMOS inputs floating at any time during operation. Unused inputs must be terminated at VCC or GND. If a system will not be actively driving an input at all times, a pull-up or pull-down resistor can be added to provide a valid input voltage during these times. The resistor value will depend on multiple factors, however a 10-kΩ resistor is recommended and will typically meet all requirements.”
Roland D-Beam 😄
That means you are worthy
Sick agentic ai communication device
Combine two, add a speaker, and you have a theremin.
It’s always a good idea to connect unused input pins to valid logic level voltages, especially with FET-based integrated circuits.
Fantastic!
it’s called electroscope, you can make it even with an IGBT, vacuum tube, a classic is a JFET
Im new and this is frying my brain i cant see a antenna or something
I am curios, given that you seem to have uploaded a video and a static image in a single post (which is what I assume you mean by “at the same time”), why are you asking why you cannot do that?
didnt read your shit, but it looks to me really nice, how simple your solution seems
What’s that got to do with an Arduino, or any serious topic if it comes to that?
Why post it?
Try shitty electronics for that sort of thing.
bruh i am new to these subs i just posted it to the first one that came in mind
It’s disgusting to try to mislead people.
If you know anything about the subject, which if you made that suggests you do, as I said, “shitty electronics” caters for little jokes.
Why do it, what’s the point?
Does it give you a thrill to bait idiots?
I don’t think OP is trying to mislead anybody, and the only baiting is you somehow ragebaiting yourself
Posts like these are why people have anxiety about engaging with social media, and why its so potentially damaging to young minds.
Unlike OP, you should have thought twice about posting. Whats the logic behind your comment? People shouldn’t share things they find interesting in case it clogs up the internet? And you thought this was so important that you just had to create a post sharing your thoughts to make OP feel bad.
You’re a terrible person and you should feel bad.
don’t be so hard on him i am sure he meant no harm honestly it didn’t bother me and calling him a terrible person over a comment isn’t exactly fair either no need to turn this into a bigger deal than it is
Explain just how its supposed to work.
What young minds are going to benefit from taking frauds seriously?
Do you even know what a NAND gate is yourself?
Wheres the Arduino?
Why is it terrible to enlighten people that they are being conned by shysters that have done a diversion from showing muppets how to get free wifi or perpetual motion?
There are forums for taking the mickey, this is not one of those forums.
You seem fun.
Doesn’t have to be specifically about arduino, people make posts about general breadboard/beginner electronics stuff/non arduino boards here all the time. Plus this teaches an important lesson on one reason why pull up/down resistors are used.
How on earth do you work that gem out?
There are a lot saying that which frankly beggars belief if any know what the 7400 series is about.
Why post under Arduino, even if it were wired in a way that implied the OP was trying to get a circuit to work, it has nothing to do with an Arduino forum. Ask Electronics is more appropriate for serious topics.
That is not a serious topic.
So come on, where is the pull up / pull down resistor to go?
Would you care to provide a readable explanation of it and its action.
No?
‘thought not!
Pins 9 and 10 (3A and 3B in the TI datasheet). From the TI datasheet 8.4:
I’m not an EE or anything so someone correct me if I’m wrong, but my interpretation is that the floating input voltage (being affected by the nearby hand) turns the PMOS and NMOS transistors of the CMOS inputs on at the same time when the inputs rise to near half VCC. This creates a voltage divider internally, and this voltage that is in between VCC and 0V will turn on both the PMOS and NMOS transistors in the NAND gate circuitry (just like the input pin voltage did). This means that the output voltage is also not going to be a nice 0V or VCC, and is instead going to fluctuate between them which affects the current through the LED.
Obviously CMOS cant be left floating, how do you propose arranging things so that the duty cycle can be altered so readily with what is after all random noise.
Tried to control using capacitance on an ESP32 at all?
Things are simply not that linear.
Apart from which the LED is far too bright for the current the gate sinks, even if it did work as you say.
Fair, but electrons go brrr
Man, you must be a chore to be around.