Questions tagged [input]

Something put into a system or expended in its operation to achieve output or a result

8
votes
4answers
1k views

Does a switch need to be debounced when opened?

Suppose that an input on a microcontroller has a pullup resistor to 5V and a switch to ground (normally open) connected to it. I know that a switch should be debounced (in my case, in software) when ...
9
votes
4answers
3k views

Does there exist an IC that allows on-the-fly routing of signals?

Do there exist ICs with N input pins and N output pins which, either via EEPROM setting or via on-the-fly control by a microcontroller, allow one to route each of the N inputs to ANY of the N outputs? ...
6
votes
3answers
13k views

What kind of diode to use with ADC inputs

I am looking for diodes to protect my ADC from over voltage conditions. From what I have researched so far, I know that I need schottky diodes hooked up from the input to the ground and the input to ...
7
votes
1answer
319 views

Input and Output pin voltage specs on a datasheet

I'm a bit confused about input pin voltage tolerances and output pin voltage values of ICs. I would think that datasheets for ICs that involve signal inputs/outputs would list two values: The ...
6
votes
2answers
2k views

Is it OK to rely on an ADC's internal protection diodes?

Related to: ESD protection of ADC input. To protect an ADC input from out-of-spec voltages, including ESD, it is often recommended to use diodes connected to GND and Vcc. If I have a 1k series ...
2
votes
2answers
8k views

difference between dry contact mode output and open collector output

We have a device which can work with dry contact input and a device which gives open collector output. Will it inter-operate? Is there any difference between dry contact mode output and open ...
6
votes
7answers
11k views

Multiplexing Inputs on a microcontroller

I have a 4 way DIL switch that I use to provide input to a microcontroller, and I need to free up a port to use for something else. Is there a way to multiplex 4 inputs into 3 microcontroller ports? ...
13
votes
2answers
18k views

opto isolated arduino input

I want to protect a pin with an opto isolator to get an external signal from an electrical meter (35VDC max, 50mA max, 240ms pulse width). The purpose is to count the pulses. Do you have some ...
8
votes
3answers
8k views

Arduino Analog Input example clarification

First of all I'm total nub in electronics. Recently I got an Arduino Nano. Now I'm trying to understand why there is no potentiometer nominal at http://arduino.cc/en/Tutorial/ReadAnalogVoltage ...
2
votes
1answer
412 views

how does better isolation between gate and channel in a mosfet, result in a higher input impedance?

I wanted to know what are the factors that affect the input impedance of a device, majorly in a MOSFET, how does better isolation between the gate (resulting in less leakage current) result in a ...
5
votes
3answers
1k views

Measuring input current of opamp

I want to measure the current that goes into a noninverting opamp input. I've setup my experiment as follows: I can't measure the voltage drop across the 10M (R1) resistor directly since my DMM has ...
1
vote
2answers
3k views

How can I interface with these 24 V signals?

I have a few 24V inputs to my micro controller from Limit switches. I have conditioned the signals as shown. Pulled down, de-bounced and level converted. I have some signals that are again 24V but ...
0
votes
4answers
3k views

PIC16F877a input always true

I am programming a PIC16F877a with 3 toggle switches and a 20 x 4 LCD. The 3 switches are soldered to pins B0 - B2 on the PIC. The other end of the switches is connected to +5v (PortsB have internal ...
4
votes
4answers
2k views

Input impedance of an op Amp

I noticed that the input impedance of an op Amp is extremely high. Why is that so?
7
votes
2answers
6k views

How to trigger a transistor from iphone's audio output jack?

I want to trigger a transistor using iPhone's audio output jack. My goal is to turn off an LED(which is fed by an external +5V battery) by sending an audio signal from iphone's output jack. At the ...
5
votes
2answers
261 views

Trouble chaining multiple low noise op amps

I want to experiment with receiving ELF signals. In particular 76Hz. The goal is to attach a coil of a few thousand turns of magnet wire, place it on the ground, and read the signal level. My ...
2
votes
3answers
8k views

DIY simple line out converter for “floating ground” car head unit?

On a 25W max power (10V p2p @ 4ohms) balanced (push-pull) high level output factory car audio head unit from which I need to feed a mono amplifier (for subwoofer) that only has an unbalanced line ...
3
votes
1answer
530 views

Arduino LilyPad Input Voltages Below the Input Voltage in Specs

The LilyPad spec page says: Input Voltage 2.7-5.5 V I understand that an input voltage greater than 5.5 V would damage the device, but what if it's below 2.7 V?...
4
votes
2answers
220 views

Handling audio (from mic to headphones)

Right, I'm new to electronics, but this is what want to know: What do I need to take a mic input, and output it to some ear phones (standard jack, can be mono). I want to build a motorcycle intercom, ...
0
votes
2answers
932 views

Conceptualizing an analog input pin on a microcontroller?

As I am trying to learn basic circuit design I would like to build and simulate simple models to test my conceptual understanding. One of the first designs I am trying to tackle is to use an analog ...
6
votes
4answers
5k views

Why won't my arduino board read an analog pin correctly?

I'm working with an Arduino Uno board. I have a series of voltage dividing circuits off to the side of a breadboard to give me four different voltages. I'm connecting to my laptop. I am using the ...
3
votes
2answers
1k views

Input clock signal with noise

I design a frequency divider in FPGA. It is nothing more than the D flip-flop, which use the inverted output as input. Then on the output of D flip-flop is signal with half-frequency of input CLK ...
5
votes
4answers
23k views

Arduino Mega 0 - 10V analog input?

Is it possible to configure the Arduino to give me 0-10V analog input? I realize that I can use a voltage divider. I was just wondering if I can use a larger range for the analog input.
10
votes
6answers
14k views

Input voltage range of opamps

I understand that, for an ideal opamp, Vo is bounded by Vee and Vcc (i.e.; Vee < Vo < Vcc). But, what about the input voltage range? What is the allowed input voltage range in which opamp works ...
0
votes
2answers
1k views

Glowing pressure plate

I need to build a pressure plate to go on the front of a prop to be used in Airsoft. The idea is this plate is both an target to be shot at and a visual representation of "health". My initial ...
5
votes
6answers
3k views

Simplest possible I/O for Homebrew 8-bit CPU

I am working on designing an 8 bit cpu as a personal project for no real reason. I am using mostly 74HC series chips and am generally focusing on ease of programming over performance. I am using ...
1
vote
2answers
193 views

Connect multiple in/outputs in predefined order (beginner question)

I want to create a device for my guitar pedals which can rearrange my pedals in any given order. I have the following: At the beginning of the device I have an input for my guitar. For each pedal I ...
1
vote
2answers
324 views

Video entry sender has only one signal line for Microphone + Speaker

I am planning on connecting an off-the-shelf door camera (audio/video sender) to my project. I've posted an extract from their manual here The video output is composite which I can support, but ...
1
vote
2answers
729 views

DPDT switch for on/off

Hey all, I'm fiddling with a breadboard to make some logic gates and instead of buying spst switches, I bought dpdt switches because they were the only ones that would fit in the board. :/ Can I ...
1
vote
1answer
126 views

Reading and Sending Values to a 104 pc I/O relay board

I am wondering how to send values to a 104 PC I/O board. There are several on the market that use a similar approach. Information surrounding the one I have in my possession can be found here. I have ...
2
votes
1answer
510 views

Input impedance

I'm trying to figure out what the input impedance of the ADF4113 is. Looking a figure 15, I'm not sure how to read that. In my setup input is on RFinA and RFinB if connected to GND via a 100pF ...
2
votes
2answers
1k views

Balancing Unbalanced Audio Inputs

I'm wanting to nicely balance some unbalanced inputs to a power amp for good CMRR, and because I'm feeling too lazy to start trying to closely match pairs of resistors, I'm looking at using a hi-fi ...
8
votes
1answer
837 views

How to implement a “rotary switch” like in audio equipment?

for my current project I'm planning to use an input "device" like this in the photo (don't know its real name): It is used in a lot of musical instruments and it is like a potentiometer that can be ...
4
votes
2answers
5k views

Configure a PIC pin for Input and Output

I am working on a project which uses a PIC24FJ64GA002 mcu. I am working on a bit-banged serial communication function that will use one wire to send data and then switch to receive mode to receive ...