Questions tagged [input]

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

Filter by
Sorted by
Tagged with
1
vote
2answers
196 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
1answer
51 views

Voltage source & current input

I am working on a project where I have a current source (analog output from a PLC) controlling a VFD. Based on the position of the dipswitch, the VFD will accept either a current or voltage input. The ...
1
vote
2answers
143 views

Several Questions About Analog Input

I am new in the automation industry, and now I am focusing on learning how to wire correctly analog inputs in detail, since last time I tried I damaged the module input because of wrong wiring. Here ...
1
vote
2answers
61 views

op-amp pin is sitting at high voltage (active low-pass filter)

I am looking at using the OP1177 to act as an active low pass filter. I need to smooth out a 20kHz signal burst with a minimum of 50 cycles to reach a voltage on the output to interrupt an ...
1
vote
1answer
53 views

Measuring 24V AC input state with microcontroller

I need to measure the state (on/off) of a 24V AC line that is currently powering a solenoid valve. The microcontroller will take over the control of the solenoid through a solid state relay, but I ...
1
vote
1answer
2k views

in SPI, can MOSI and MISO be connected together?

I'm using an 8051 series microcontroller, and documentation states that if I use serial mode 0, then its RXD pin can function as a bi-directional pin (both input and output) while TXD is strictly a ...
1
vote
1answer
104 views

Can I use a similar AC adapter with different input but the same output?

I have a landline telephone from Japan. The owners manual says only use OUR AC adapter, {Input 100v 50/60Hz 8VA - Output DC 11V 430mA} I want to use this in North America - can I use a AC adapter ...
1
vote
2answers
157 views

A huge number of buttons on a Raspberry Pi

I am working with a friend (he's got the vision, building the structure, I'm working on the electronics) on a large scale project that involves a grid of pictures illuminated by an LED at the push of ...
1
vote
1answer
196 views

Industrial level input protection

Take for example a Siemens S7 24V digital input. I read a couple of articles and also questions on SE and it seems there should be (maybe integrated, maybe as a discrete part): optocoupler to ...
1
vote
3answers
113 views

Simulating keyboard input onto ribbon?

I'm considering starting a project that would require me to transfer data onto a keyboard ribbon in such a way that it mimics typing. Would it be possible to do this through wires connected to the ...
1
vote
2answers
337 views

Input range of operation amplifier

Lets have a look at the following circuit: (Input waveform is sinusoidal and Vpp would be ~32V) The input waveform should represent an AC Source from a ...
1
vote
2answers
99 views

Need an extra pin to control my driver board

I've been searching for a way to add an extra pin to a driver board. The MCU board that i'm using only has 8 pins on the left side and i'm already using all of them. 2 are for powering the driver and ...
1
vote
1answer
1k views

How can I detect an open analog input pin?

Many of the Renesas micros have built-in support to precharge or discharge the sampling cap on analog inputs to be able to detect when the external circuit is disconnected. In the sample image, when ...
1
vote
2answers
139 views

A 4.8v reading on a loose pin 0?

I have a setup that demands that I use all my I/O's on my Arduino Uno R3 board - including the serial pins 0 and 1. So I've initialized those pins as inputs, but when I make a reading on pin 0 it ...
1
vote
2answers
327 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
3answers
2k views

stm32f4 vdd and interfacing input pins

The stm32f4 discovery datasheet DS8626 specifies vil and vih as below So I have some questions based on the documentation How do I know that what value VDD is operating at if I use the usb to power ...
1
vote
2answers
129 views

Signals shorted when connected to the input of an unpowered IC

I use one SPI bus from CPU to two FPGAs with different (i.e. individual) CS signals. The CPU and first FPGA are powered up, and the second FPGA is unpowered. When I send SPI signals to both FPGAs, ...
1
vote
1answer
573 views

Sallen Key topology input and output impedance

Ideal Operational amplifier Zi=(R1+R2)||Zc2 Zo=0 741 Operational amplifier Zi=(R1+R2)||Zc2 Zo=0 (at DC) For the input impedance when using a 741 I am not sure if I should consider the Fairchild ...
1
vote
1answer
241 views

harvested a joystick from a fight con, want to use it to take input into an arduino. how do I wire up the switches?

the joystick is just 4 switches around a shaft (up, down, left, right)- 0, 1, or 2 of them are engaged depending on direction the joystick is being pulled. here are some images showing what I'm ...
1
vote
3answers
913 views

Three different schemes to amplify audio input, which one is correct?

I'm building an audio amplifier (prototype) with display and MCU (Arduino Nano), see photo below (not finished ;-) ). On the display I want to show some VU-meters of the input but there are ...
1
vote
2answers
587 views

Detect 220Vac signal on Microcontroller

I'm developing a module and the control switch may be at long distances. Considering I have the 127 or 220Vac input, I want to use that for switch signal. I believe is better, instead of making a ...
1
vote
1answer
304 views

FPGA input pin internal floating

I am now occouring a FPGA pin damage problem. One of my pin is hardware connected to a 1.8V signal that will be switched on/off occasionally, while the port is not connected to any other logic gate ...
1
vote
1answer
238 views

Power In does not Equal Power Out

I have the following setup: 480V, 200A service fed into PWM Drive, Drive output going to 1000kVA step up transformer (8.4 ratio) feeding a 2380V/53A 3phase induction motor. The motor is UNLOADED. ...
1
vote
2answers
553 views

Operational Transconductance Amplifier Input Configurations

I recently purchased several OTAs (Lm13700) but have had quite a bit of trouble using them. Going through the TI datasheet and a Nuts & Volts tutorial it's occured to me that transconductance amps ...
1
vote
1answer
102 views

Number of possible IOIO pulse inputs

Looking at this page it mentions that double precision digital pulse input (32-bit timer) can be divided into 2 single precision 16-bit timers. https://github.com/ytai/ioio/wiki/Pulse-Input It says ...
1
vote
2answers
155 views

How does one implement the following function with these tools provided?

Suppose I have a function defined as follows, such that it is expressed in POS form, with the product of the following max terms of 4 variables (A,B,C,D): 0,3,4,7,9,10,12,15 and I only have a 4 to 1 ...
1
vote
1answer
303 views

PIC (16F627A) inverted inputs

I'm having problem with inputs of my PIC. There is somethink like "default value" on all inputs set to logical 1 so if I want to change the state I need to pass GND. How can I turn it "otherwise"? ...
1
vote
1answer
2k views

Build an Audio Toggle Box

I want to build a small box with two audio inputs and two audio outputs, with two switches to control the current input/output. Something like this: http://www.youtube.com/watch?v=mQzLnt0_-zU I've ...
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 ...
1
vote
2answers
71 views

Illuminated LED and push-button using only 2 wires

I want to make a circuit with an illuminated LED push-button that is far away from the input board and I only have 2 wires available. The push-button is not something specific. The input board will ...
1
vote
0answers
38 views

What is input to the RF power amplfiier (gate of the MOSFET)?

I have read that the RF PA is a block just before the antenna. So, the input to the RF PA (voltage signal at the gate of trasistor in the PA) should be a modulated signal and thus the PA just does the ...
1
vote
0answers
47 views

Input of BLDC motor

Among the brushless DC motor, is there a motor with two input wire? I thought that bldc motors with hall sensors should have 2 input, but it was hard to find such one. Is it wrong concept about bldc ...
1
vote
0answers
32 views

Noise on Input Buttons for H-Bridge

I'm constructing an H-Bridge to control a linear actuator. I've done so by using a 2-channel relay module, some buttons, and a ESP32. I do not believe this is an issue of debouncing as I account for ...
1
vote
0answers
265 views

Measure input capacitance of I/O pin

I'm looking for a simple laboratory procedure (and required equipment) to measure the input capacitance of each IC I/O pin. Thanks in advance.
1
vote
1answer
98 views

Input voltage limits of AD8495 (thermocouple amplifier) vs supply voltage

I'm working on an android multigauge for cars based of a pic microcontroller. Some inputs from sensors are not fed by my circuit so after stumbling upon this thread: http://www.microchip.com/forums/...
1
vote
0answers
633 views

Audio input: stereo to mono and filtering DC

I have to get an audio input from a PCB 3.5mm jack and summing right and left channel into one (mono). Then, I have to filter any DC noise from the input. Resistors are 1kOhm each. This, for now, ...
1
vote
0answers
130 views

Bell button as input

I got a simple bell system from elcom. It works with 12V AC. When I measure the voltage at the switch it is 1V when not pressed. When I measure the switch sides to the power input of the bell system ...
1
vote
1answer
246 views

Combine 1 connector for in and output

To simplify the outside design as much as possible (keeping it simple to use and less expensive) I would like to use just one small 2-pin connector both as output to drive an external led and as 5V ...
1
vote
0answers
565 views

P-MOSFET based automatic power selector

I have designed the attached power selector circuit, it has a 12V input and a 15V input, and should prioritize the later. It operates in three different scenarios: 1- 12V source R76+R79 divider ...
1
vote
2answers
194 views

ATMega32u4 output power to input without external resistor?

I am new to electronics and have a SparkFun Pro Micro clone with an ATMEGA microcontroller. I wanted to know if I could set one pin to be an output that sends power to another pin that I have set as ...
1
vote
1answer
1k views

When setting pin as input it getts pulled high, why?

I've hooked up a push button to GP1 and a LED to GP2 on my PIC12F683 and this is my code: ...
1
vote
0answers
288 views

Should my external analog input be isolated?

I want to build a device that samples analog signals from various measurement instruments via their analog outputs. The instruments have their own power supply, and all devices are powered from the ...
1
vote
2answers
267 views

dsPIC 30F6012A will not read RD9, appears to be software problem

I'm using a dsPIC 30F6012A. I have two PCBs with this chip, both displaying the same symptoms, implying it's not one-off damage. RD9 is definitely being driven to five volts, confirmed with a ...
1
vote
0answers
423 views

button input staying high?

I have a setup with 12 buttons. 10 of them connected to the arduino pins 0, 1, 6, 7, 8, 9 and analog 0, 1, 2, and 3 (these are all configured with pinMode as inputs in the setup-part of the sketch). ...
1
vote
1answer
94 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'...
1
vote
6answers
198 views

Optocoupler Characteristics

In my application I need to isolate a PWM signal @ 1 kHz, which is generated from a Beaglebone Black microcontroller. In my signal, I want to have one hundred different steps in duty cycle (from 1% to ...
1
vote
1answer
885 views

Duplicate MIPI CSI2 camera (one camera, two receivers)

I would like to feed two processors with the same MIPI CSI2 camera. I cannot afford to have one of the processors to play the role of proxy to the other. Though I searched hard, I'm not aware of any ...
0
votes
2answers
122 views

Texas Instruments Schmitt Trigger inputs

Hi I want to use the TPIC6C595 in some project. Because my application needs to be very noise insensitive I am wondering whether the shift register uses Schmitt Trigger inputs for G, SRCK, RCK, CLR, ...
0
votes
3answers
226 views

Simple Circuit Analysis, why this cap is needed?

This is a sub-circuit that is part of larger design and I was wondering why the designer choose to use C1 inline with the BJT base? and what does the combination of R1, C1,R2,R3 do? Since the max ...
0
votes
2answers
445 views

How can I design an isolated, wide-range digital logic input compatible with AC and DC voltages from (say) 5V-300V?

There are some excellent suggestions on how to create a wide-voltage range digital logic input on this question. The question is very similar to my needs. I'd like to be able to detect the presence ...