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Questions tagged [detection]

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0
votes
1answer
32 views

Detection of Acoustic signals

There is a scenario: There is a certain box which emits acoustic signals at 30kHz and you are trying to detect these signals using some sort of detector. I was wondering, would it be more efficient ...
0
votes
1answer
56 views

How to mute microphone in 2-way communication when the speaker is active?

I'm making my own two way intercom for my house. There will be a speaker and microphone above the front door of my house (as well as a camera). When someone rings my doorbell, I get a notification on ...
0
votes
2answers
64 views

Is there such thing as a Laser beam detector that returns a non binary result?

As the title implies , i'm looking for a device that can detect at what point a laser beam has been broken. So idea would be the device to output a certain voltage depending on where someone's finger ...
0
votes
6answers
128 views

Electrically detecting a not connected input

I have a 0-30V DC signal and it can be physically disconnected from a circuit. I need to detect and generate a TTL output when this signal is disconnected. The "detector" circuit and the signal will ...
-3
votes
1answer
70 views

Detecting a feather touch [closed]

New to the forum here, but I have a need to detect a feather touch. Is there any sensor that is recommended? This will be in a vibrating environment, so audio is probably out of the question. Is a ...
1
vote
2answers
125 views

Package detection in datastream on FPGA

Hardware: I have an asic-"sensor" which sends me 32-bit packages (serial). I need to detect this packages with an FPGA. When I start the readout, the sensor is sending me data-packages until I stop ...
2
votes
2answers
144 views

Detect if 470pf capacitor is in series with motor, using only two wires

Short Version: How can one detect if a vending machine motor is in its home position? Long Version: I am trying to make a circuit that would fit most of the motors used in the coil vending machines ...
0
votes
1answer
18 views

Variations in RFID USB Serial reader detection distance by connected device

I have a RFID reader that sends the TAG information over USB serial. I have had some troubles with it in a product where the detection success rate changes alot depending on what the USB RFID tag is ...
1
vote
4answers
148 views

Is this line detector safe?

I'm thinking about building a basic AC mains voltage detector. I'd like for it to be both protected and isolated, so I have a zener TVS and an optoisolator. R1 and R3 are chosen so that between them,...
1
vote
2answers
40 views

Pulse Train Sampling Rate

Assume I have a pulse train with frequency of F Hertz. A normal square wave has all odd harmonics. From Nyquist, if I want to "Reconstruct" the waveform, sampling frequency Fs should be at least 2*(...
0
votes
0answers
47 views

SNR wall definition

I want to ask you if my understanding of the definition of the so called "SNR wall" is correct and complete. The SNR wall phenomenon is described here and here. If one has further information that ...
0
votes
3answers
82 views

How do I keep the “detected” state ON in a PIR detector until a human has left the detection area

A PIR detector stops alarming after a while, if a human in the detection area doesn't move. How do I keep the alarming state ON as long as there's a human in the detection area even if he doesn't move?...
0
votes
0answers
55 views

How do I tell if my Lidar sensor will detect an object of a certain size?

I'm considering buying a Benewake Lidar sensor for the purpose of detecting a 1 inch diameter tube that's 12 feet long from ~3 meters away. The tube will be laid perpendicular to the sensor's beam. ...
0
votes
0answers
193 views

Non contact voltage tester

I built myself a very simple non contact voltage tester with a couple of transistors, an LED and a wire at the end to work as an "antena" like the picture demonstrates: It's for a school project and ...
-1
votes
1answer
100 views

long-distance sound detection/recording solution? [closed]

My general requirement is an audio input system which can effectively detect sound signal (80dB at about 5cm) over 30 meters away. The supply voltage should be within 5V so that the system can work ...
2
votes
3answers
449 views

Analog (POTS) telephone off-hook detection

With a single POTS telephone line and two or more handsets, when a call comes in, each handset can join in with the call. This can sometimes be an issue when one user doesn't know the line is in use, ...
0
votes
2answers
238 views

Non contact (contactless) AC or DC detection?

I'd like to detect AC or DC current (not the current level just nothing or something => ON/OFF) in a wire with a (DIY) sensor just in contact (glued) with the wire plastic insulator. At the end the ...
-3
votes
1answer
220 views

Detection of lung sounds using a stethoscope and a sensor [closed]

I am currently working on a on a project for detecting sounds which uses a stethoscope, where its one end is connected to a sound detection sensor which is further connected to an Arduino board. The ...
0
votes
1answer
70 views

Voltage Detection via Analog Comparator

I'm currently designing a PCB at which I have an lithium ion battery (4.3V max) attached. The battery is charged via USB (5V). The charging controller is enabled by a microcontroller which should ...
-1
votes
1answer
90 views

Radio frequency detection without digital clock [closed]

Is it possible to have a circuit that does something (fires a pulse, turns on a voltage, whatever) when it detects a radio signal at a specific frequency? One crucial point is that it should do this ...
-4
votes
3answers
147 views

Detecting human body current with raspberry pi [closed]

I want to be able to detect on my raspberry when a human contact is made with a GPIO pin (or a cable linked to a pin). I am pretty sure it's possible (for example when i see this kind of projects : ...
0
votes
2answers
116 views

USB Drive detection circuit [closed]

I am building a simple portable speaker using a DFPlayer Mini, but I think that's not entirely relevant to my question. I am looking for a way to detect when an USB Drive is plugged in, so the player ...
-1
votes
1answer
266 views

presence detection using Panasonic grid eye [closed]

I want to use grid eye AMG8833 for presence detection. Has anyone used gridEye for the same purpose? Or Can someone suggest algorithms to decide whether someone is present beneath the sensor or not ?...
0
votes
2answers
40 views

Sensing Mobile Battery full and cutting down power on V_bus line

I just come across the situation to cutoff the power when mobile battery full is detected (by breaking the +5v line) .I planned to implement this using high side current sensing method.When the ...
0
votes
1answer
81 views

RFID (or other) - Proximity Detector

I am trying to detect how often 2 animals 'interact'. Say I have 4 cats, I am trying to work out how often each of the cats interact with each other. I have considered using RFID tags attached to ...
0
votes
1answer
91 views

Inductive Coil - detecting open coil

We are using an inductive coil transformer for a sensor. We excite the signal with a low frequency (1kHz-3kHz), and what we measure on the secondary indicates the proximity of a part. Generating the ...
26
votes
7answers
5k views

Smart ways to detect a button (less power consuming)

During a meeting for a particular project I was asked to think about the way to detect a push on a button with a MCU. The detection should consume as little power as possible. At the first glance, I ...
0
votes
1answer
45 views

Phase-frequency detector not used in a PLL

My application: I need to output a voltage based on a phase difference between two input signals (a voltage and a current). It seems that a phase-frequency detector will do exactly this but I have ...
5
votes
7answers
346 views

How to detect if a nearby parked car has started engine?

We have a project with a machine servicing a car parked next to it. It's comparable to a car washning machine. Before the machine is started, we need to be 100% sure that the engine is off. Also, if ...
2
votes
1answer
77 views

What kind of sensor could detect the valve of a rotating soccer/rugby ball? [closed]

I am trying to design a device that will detect the air pump valve of a ball and then rotate it to a home position. It will most likely be controlled by an Arduino. I am a mechanical engineer and ...
4
votes
2answers
75 views

How can I measure moisture on a conductive flat surface as an analog/digital value?

So as the title states, the question is: Is there a way to measure moisture on a electrically conductive flat surface? Optionally, it would be great if I could have an indication of the amount of ...
4
votes
2answers
4k views

How to trigger hot plug detection in HDMI interface?

I'd like to trigger the hot plug detection circuit for one of my graphics card's outputs so that Windows would "think" that it has secondary monitor attached. I know that there is a pin in the HDMI ...
4
votes
4answers
840 views

Detect and measure fog outdoors

Currently working on a project requiring me to detect fog, and measure the amount of fog. It doesn't have to be accurate but it has to give a sense of how foggy it is. The device (probably Raspberry ...
0
votes
1answer
136 views

How to detect obstacles (Tripwire with Laser, IR or similar)

Supposing I have a glass sheet 50cm x 30cm, with 10 holes (2 lines x 5 columns), with metal/plastic (i can chose) pins inside it. They can be flush (hidden in the hole) or salient (extending 2mm above,...
-1
votes
2answers
354 views

How to detect if coaxial connection is plugged in?

I'm designing the power stages at the moment and I'd love to disable unneeded circuitry when nothing is plugged in. Right now there are two options to plug something in to get things going: USB and ...
0
votes
0answers
132 views

Why does a foster seeley circuit need transformer coupling?

Having read most of the online references to this circuit and performed some simulations, I still don't have a firm grasp on how this circuit functions. Here's a schematic to refresh (possibly ...
0
votes
2answers
1k views

Water leak detection sensor and circuit

I am planing to build a ROV for underwater use and at this point I am concidering to have some water leak detection system for the electronics enclosure that has to withstand underwater pressures up ...
1
vote
1answer
2k views

Test circuit to confirm RF receiver frequency? (315Mhz vs 433Mhz)

I've bought a 433 Mhz Transmitter/Receiver pair, or so I think. I cannot make them work, and I started to think that maybe the seller sent me a 315Mhz transmitter / 433 receiver pair by mistake (I've ...
0
votes
1answer
327 views

Circuit activated by pulse

Looking for a simple circuit which output is only active when its input is a low frequency (0.2-0.5Hz) pulse. The circuit output should be deactivated if input is unchanging. I tried monostable 555 ...
2
votes
3answers
436 views

Trying to understand what I'm seeing on my oscilloscope

I've been working on this project on and off for some months now and am really at a loss as to the nature of the signal I'm seeing - really hoping someone can help me out with this. Let me start off ...
2
votes
3answers
130 views

Lightning detection

I am planning to build a device that has a capability of early detection of a lightning. Also we want to measure the magnitude of the lightning and can anyone suggest a way to measure the magnitude of ...
0
votes
2answers
153 views

Building a (toy) Ghost Detector

I'd like to build a ghost detector. I'm only just beginning the design stage, and thought I'd reach out for some suggestions. Receiver: I'm planning to end up with a handheld device with an analog ...
0
votes
1answer
804 views

USB plug in detection for charging port

Is there a way to detect if there is a USB cable physically inserted into a USB receptacle, even if it is just a cable (with nothing attached to it). I am designing a USB charging port (short D+ and ...
0
votes
2answers
227 views

How to read a high voltage signal with Arduino (wirelessly)

I am trying to build a tachometer for my motorcycle, something like this: https://youtu.be/GmLaNy2NBcQ What I need to determine is the time between two spark plug "sparks". How could I determine ...
-1
votes
1answer
101 views

Question about Color Sensors

Can a color sensor detect more than one color at once WHILE distinguishing them? For example: Say I wanted a program to activate only if both red and violet are detected at the same time. Is that ...
1
vote
1answer
479 views

Are these SMD aluminum electrolytic capacitors busted?

I recently bought a car radio and made a stupid mistake when I connected the radio to the car. Apparently I reversed the polarity on the radio which made the radio go poof and smell awful. After ...
0
votes
1answer
69 views

Presence Detection of Factory Machines for Their Traffic Management

I'm currently planning a system for traffic management inside a factory (of its wheel kind machines). Typically, I would use an inductive sensor which would react and indicate the vehicle presence. ...
0
votes
0answers
71 views

Cheap spectral analysis to analyze water quality

Is there an expert in optics here? I need some guide about spectrometers I saw a lot of DIY spectrometers to analyze light. Does anyone try to use those DIY spectrometers to analyze water? To ...
0
votes
0answers
55 views

Build a breathalyzer like device but for testing liquid or semi-liquid subtances

As a recovering alcoholic, I know for a scientific fact that alcohol will altogether evaporate from boiling water after sufficient time, and nearly all alcohol from boiling food, which would have a ...
0
votes
1answer
406 views

MQ-7 Module Carbon Monoxide

I'm a student in Computer Science but, unfortunately, I don't have much experience with the electrical part. I need to detect the carbon monoxide level for a prevention system using an Arduino board; ...