Questions tagged [capsense]

Questions regarding Capacitive Sensing as an input method. This can vary from simple Capsense buttons, to high resolution Capacitive screens, to Capsense programming methods.

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Help required regarding Cypress 4200 coding

I am a newbie when it comes to Cypress chips. I am developing a capsense keypad. I recently started with CY8kit049. I can code into the chip on board. How can I code other PSOC 4200 chips too using ...
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2answers
240 views

Why does my home-made capacitor have an apparent polarity?

The Problem I've built some simple capacitors to use as pressure pads on the stairs at home - the aim is to light the stairs up as you go up them - here it is in action. But I'm getting weird ...
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1answer
187 views

Detecting touch using electrical noise on microcontroller pin

I have recently been experimenting with detecting touch on a microcontroller digital input pin using the following method: Put pin in output mode Drive the pin high Put the pin in input mode Time how ...
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1answer
632 views

Capacitive touch screen sensitivity question

I have a question about capacitive touch sensing. I have read a few related questions already (here, here and here) and I think I understand the basics. From my understanding, when a human uses a ...
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2answers
946 views

How does this capacitive soil moisture sensor work?

I’m trying to figure out how the following soil moisture sensor works. It’s obviously a capacitive sensor where the capacitance changes when the soil moisture varies. However, as you can see, the ...
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3answers
421 views

Sensing the capacitance value of a material - for an ID system

This is a follow up question to 'How does a Capacitive ID / Signatures / Sensing system work? e.g. Google Bloks' In the 'Google Bloks' project. A tangible programming experience is created by ...
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2answers
732 views

Shielded cables to capacitive sensor?

In a hobby project I am using shielded cable to connect capacitive sensor's electrode (see https://electronics.stackexchange.com/questions/189916/capacitive-touch-not-working-at42qt1011 ) to the ...
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1answer
2k views

Simple capacitive proximity/touch sensor problem

I've found one simple schematics for capacitive sensor on electronics-project-design.com, and implemented it as follows: The B? is 9v battery. Sorry for the odd-looking schematics: gschem usability ...
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1answer
237 views

Capacitive Touch and implementation with BeagleBone Black

How might I make a basic capacitive touch sensor for the Beaglebone Black that is capable of sitting behind an insulating material? I would like to make it as basic as possible, and without any sort ...
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2answers
894 views

How could I make a water-resistant touch/tap sensor (similar to push button) for all-weather outdoor use?

I am building an Arduino-based device to be used outdoors (on a bicycle), and it is expected to work in all weather conditions. The device will have some buttons to turn lights on and off, honk the ...
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5answers
593 views

What sensor(s) to detect (frozen) steamed up mirros?

I am trying to build a (solar powered) device that heats up a mirror a bit until all steam/mist that was on it is gone. In the winter, the water is frozen. This is to remove any visual obstructing ...
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1answer
146 views

A (touch) screen technology to identify several input devices

This may sound vague, since I am not sure if what I am looking for even exists, but please bear with me. I am interested in a technology that would allow me to not only locate, but also identify ...
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2answers
1k views

Why are the values I'm getting through a capacitive sensor decreasing as the resistance gets lower?

I'm currently messing around with "capacitive sensors" by trying to light an LED using an Arduino. My capacitive sensor that I am using is just made up of an Arduino, three wires and a resistor. My ...
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1answer
2k views

How internal capacitor stud finders work?

I don't understand how can a non magnetic object like wood be detected using a stud finder For instance, stud finders find wood from dielectric constance, but I don't understand the princible. The ...
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1answer
5k views

Capacitive touch sensor grid to the Arduino?

I am trying to build 8x8 grid that consists of capacitive sensors which we have successfully made by using a high resistors and copper sheets. I used Arduino's library to control it, but my problem is ...
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2answers
1k views

Capacitive sensor wiring

I attached some wires to a microcontroller for capacitive proximity sensing of fingers or hands. The sensitive areas are of several shapes. For a compact shape, I just put some wire in spiral ...
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2answers
6k views

How does the Arduino CapSense library work?

Can anyone give me some help in understanding how the Arduino CapSense library is able to sense proximity? From reading the source code, it seems that it toggles a sending pin and then waits for the ...
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2answers
1k views

Transistor selection for 5V LED circuit

I'm having a trouble selecting the proper transistor to switch this LED circuit simulate this circuit – Schematic created using CircuitLab The LEDs are 3.6v at 20 mA. I tried figuring the ...
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1answer
2k views

iPhone touch screen pulse generator?

I saw this video on Vimeo http://vimeo.com/23507315 and am amazed. Does anyone know how this works? Dies it send a pulse or switch ground? What is the wheel he is turning? What is that big gray thing ...
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2answers
997 views

ESD protection of capacitive touch doorknob circuit?

This is a follow-up to my question: How can I use a generic doorknob as a capacitive touch sensor? I am now ready to move beyond the proof-of-concept stage, but I have not yet learned of a ...
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6answers
2k views

Draw a small amount (30mA, burst to 300mA) of DC (~5v) power from 2-wire wall switch?

My question: I'm installing an arduino behind a wall switch. The light switch only contains two wires. the hot/live wire and the wire going to the light fixture. There is no neutral in the wall socket....
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3answers
2k views

Is a human (or other) electrical signal absolutely necessary to activate a capacitive touchscreen?

I know this is the general wisdom, and that someone has asked a similar question here: How can a capacitive touch screen be triggered without human contact? However, I didn't quite understand the ...
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1answer
2k views

How can I use a generic doorknob as a capacitive touch sensor?

I would like to use a generic doorknob that's installed in a typical wooden exterior door as a capacitive touch sensor. I have found various references for the circuit, but I have some questions about ...
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1answer
5k views

How to use the CTMU (Charge Time Measurement Unit) for a capacitive touch sensor on PIC24F?

I'm trying to implement a basic touch sensor using the CTMU on my PIC24F04KA200. Reading the datasheet and application notes provided by Microchip I was expecting this to be an easy endeavor. In this ...
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3answers
9k views

Simplest touch sensor for a copper surface

I'm looking for the simplest way to implement a binary on|off touch switch using a single pole. The touch surface is copper. The position or pressure of the touch is not needed, just simply: On = ...
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5answers
50k views

How to use a capacitive touch screen without a human hand

I'm a programmer, and I usually hang out over on stack overflow, but I have a electricity question. I'm trying to interact with an APP on my phone by indirectly touching the the screen. Modern ...
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4answers
2k views

How do i make a micro-controller act as a finger on a touch screen?

I want to make a device that i can place on a capacitive touch screen and it will start tapping the screen repeatedly. Is there any way to do this with the Arduino?
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1answer
3k views

Accidentally made an analogue touch sensor from arduino digital pins

The other day I wrote a simple arduino script to switch on an LED when a pushbutton is pressed. Without connecting the pushbutton, the circuit created a make-shift analogue sensor that varies the LED ...
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1answer
306 views

Replacement IC for the touch-button QT1081?

A project I'm working on needs several touch buttons. I found the datasheet for the Atmel QT1081, which supports up to 8 capacitive buttons, with the added advantage for our circuit that there are ...
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1answer
92 views

Capacitive pen input sensors on screen edge

I've got a couple Kobo Touch devices in my possession. I've recently started hacking on the software. I'd love to enable stylus input by putting a Wacom or similar tablet behind the screen, but I don'...
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2answers
7k views

How feasible would it be to use capacitive detector through 5 mm thick glass with a gap between PCB and glass?

I'm researching for a project that would need to have some sort of touch detection through a 5 mm thick glass table. Would it be feasible to use a PCB with appropriate patterns and a mTouch/QTouch/...
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2answers
3k views

Capacitive touch sensors, how do they work?

David mentions capacitive touch buttons in EEVblog #130 - The uCalc Credit Card Scientific Calculator / Computer and indeed I have read about capacitive touch buttons before like in the documentation ...
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1answer
716 views

Capacitive touchscreen [duplicate]

I am doing project in which I want to perform read and write operation by using a capacitive touchscreen. What I know is I can trigger capacitive touch screen by: By using electromagnet as I heard ...
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4answers
1k views

Touching Person-to-Person

Is there any way to detect skin touching or no-touching between two people? Maybe using capacitive sensing or any other methods? It doesn't need recognizing gesture, only yes-or-no-touching. The ...
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1answer
486 views

Capsense behind glass

Is it possible to make a capsense sensor that works through a sheet of glass? I have a working capsense sensor on one of these PSoC development boards: The buttons work fine, but when I put a sheet ...
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2answers
1k views

Wiring a capacitive touch sensor to the Arduino?

I have just recently bought a few different ic's from Mouser.com, not thinking i never even looked to see if i could use them. I Wound up getting a few Azoteq IQS128 capacitive touch sensors, but I ...
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1answer
824 views

How to make an entire (irregular) surface sense touch with a capacitive sensor?

I'm looking for a way to make a surface touch sensitive. The sensors have to interface with a keyboard encoder to send signals to the computer as keypresses. This is just the way it has to operate. I ...
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5answers
25k views

How can a capacitive touch screen be triggered without human contact?

I want to robotically touch an iPhone screen without any human intervention. I've done some experiments but have not found a reliable solution. It seems even styluses that work through gloves still ...
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4answers
4k views

Triggering a capacitive sensor electronically?

I'm working on a little project I call my "Green Box". Basically, I'm trying to drop my electric usage as low as possible, without losing the convenience of my gadgetry. So far, I'm incorporating a ...
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6answers
6k views

Can a water drop do a “fake” touch on a capacitive touchscreen?

If a capacitive touchscreen is hit by water drops, like rain, will it report a touch? I'm trying to evaluate what is the most appropriate touchscreen solution to use in an outdoor kiosk.
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5answers
4k views

What exactly is the use of PSoC?

Hey, yesterday I saw a demo (which was actually meant for my seniors) of a PSoC 5 board by cypress at my college. They demonstrated how to use the capsense built into the board and one of the PSoC ...
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2answers
8k views

How do I get an Arduino (5 V) and MPR121 (3.3 V) to talk?

I have the Sparkfun MPR121 I2C Capacitive touch sensor breakout board I have read that it uses 3.3 V, I know that I can't just connect up the 3.3 V power supply output from the Arduino as the ...
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8answers
6k views

Sensing touch through a thick surface?

How can I sense the touch of a hand through a thick surface? I'm working on a device that has to be completely enclosed in a 1-2" thick wooden casing (or 1-3mm thick metal) due to design requirements, ...
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6answers
2k views

Capacitive Sensing

Is there a way that I can make an Arduino or other Micro-controller detect a change in capacitance? I'm thinking of having a screen on my door that only turns on when you touch the metal door handle.