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Questions tagged [resistor]

Passive electronic component which reduces current flow in a circuit, dissipating power as heat.

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0answers
34 views

Control 12V power with 3 transitors to 3 seperate consumers

I have this shematic. With one electrical Pump and two solenoid valves I want to control via the arduino. Here are the specs for the parts: Pump: 12V max. 250mA Valve 1: 12V max. 160mA Valve 2: ...
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1answer
69 views

Menus not changing when button is pressed TFT 128 x 128

I've just followed a tutorial so that when a button is pressed it goes through a menu. Click once, next slide. Only issue is it isn't appearing on my screen at all. It has uploaded but I'm a total ...
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0answers
27 views

Why do we need this resistor? [duplicate]

What is the purpose of it and on what bases its value is calcuated in ohms ?
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5answers
151 views

Why does the transistor burn out

I have an arduino uno which turns on a water pump (12V, 3.6W) once every 10 hours for a few minutes (I've followed this tutorial on how to connect the water pump). To turn on the water pump I used a ...
2
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2answers
184 views

measure +3V and -3V through resistor divider and switch on/off by digital pins

I've seen that resistor dividers can be used to read negative voltages, but I'ld like if there is a way to accomplish this with less components and having a way to turn this off. I was thinking if ...
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2answers
37 views

Load Resistor Use for Voltage Sensing by Arduino

I connected a piezoelectric film to a Arduino Uno board via analog input. However, as I was getting very high voltage values (reaching 5 volts without much movement). Therefore, I added a 1 megaohm ...
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2answers
107 views

Why does current flow along a wire instead of a resistor right next to it? [closed]

I am having trouble understanding exactly what is going on in a circuit where when a button is pressed an LED goes on. Also, I have the Arduino UNO. The schematic can be seen at: 2:36 of this video: ...
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3answers
95 views

Arduino Uno with 6x 5V solenoids + 9V battery - Not enough power?

I have 6 5V solenoids connected to an Arduino Uno, each of them with a TIP120 transistor, diode and resistor. Exactly like https://core-electronics.com.au/tutorials/solenoid-control-with-arduino.html ...
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1answer
77 views

What should the cut-off frequency be? [closed]

To convert a PWM signal to a DC voltage it must be filtered with a low pass filter. How can you know which cut-off frequency should be used and how do you calculate the values for the resistor and ...
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1answer
60 views

Connecting DAC output from Arduino Due to another arduino

I have an Arduino Due and I want to connect the output from the DAC as an input to an Arduino Uno's analog input pin. From this link http://forum.arduino.cc/index.php?topic=164763.0, user DuaneB ...
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1answer
56 views

Do all pins of Arduino Uno output 5V?

I am currently working on a project which uses PIR motion sensor and 5V relay. Since you might be familiar that both the motion sensor and the relay requires a 5V connection. My problem is, I don't ...
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2answers
99 views

Would a 100KΩ resistor connected to ground pull an open analog line down to 0

I have a project that has a photoresistor wired into a voltage divider and connected through a 3.5mm “stereo mini plug”. When nothing is in the mini plug, the analog line is an open circuit, and ...
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0answers
16 views

Arduino Uno Force-Sensitive Resistor

Would any one know how many Force-Sensitive Resistors that a Arduino Uno can handle being hooked up to at one time?
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3answers
629 views

Multiple I2C slave devices on Arduino - Pull-up values

This question is asked a lot and I've found many usable details on different forums regarding adding pull-up resistors on SDA/SCL lines. I know that only one resistor should be added on these lines ...
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1answer
82 views

Sanity check for dual IR LED circuit [closed]

If the intent is to drive the two LED's with 200-400mA (using PWM @ 38Hz), is there anything wrong with this solution? Perhaps this is a better solution, as it ensures the current is exactly the same ...
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1answer
348 views

Preforming impedance termination for UART Communication (TX and RX) pins

I need two Arduino devices (Arduino Mega and Nano) to communicate with each other via UART. The two Arduino devices are long distance apart from each other. The distance is 1.5 meters. The Arduino 1 ...
2
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2answers
2k views

How can I tell the resistance of an internal pull-up resistor?

I have a SparkFun ESP8266 Thing Dev board, to which I want to perform a digitalRead() on one of the GPIO ports. I'm using D15, and I'm configuring it for input like this pinMode(15, INPUT_PULLUP); ...
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2answers
270 views

Resistors on LCD - does a small difference matter?

I recently have tried to connect an LCD to my Arduino Uno. The tutorial tells me I need a 220 Ohm resistor, but the only ones I have are 330 Ohm. Does it matter? Here's the Fritzing diagram by the ...
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1answer
778 views

Pulse counter to measure flow-rate: 0 Pulse issues

I am using a Netafim M-Series flow meter interfaced with a UC-32 Arduino. The goal of this is to create a pulse counter than in turn will allow us to determine flow rate in the meter. (1 US gallon per ...
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2answers
37 views

Schematic interpretation, where to put resister?

I'm new to schematics, trying to figure out where to put a resistor (no instructions other than the schematic) I'm told I need: 10K variable Resistor x 1, 4.7K Resistor x 1, 100 Resistor x 1 But I ...
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1answer
40 views

Does blinking an LED with no resistor for a few seconds harm my Arduino?

I am new to Arduino and I just made my first LED blink. I connected the LED to ground and digital pin 13 without resistance (for only a few seconds). Does this harm my Arduino? Hilmi
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2answers
2k views

Minimum value I2C-pull up resistor for arduino

I'm trying to determine the minimum value of pull resistor for Arduino Uno The datasheets says for arduino; VOL = 0,4 for IOL = 20 mA. (VDD = 5V) For formula for calculation of minimal pull-up is: ...
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1answer
203 views

Minimum value of a pull-down resistor

I've just started working with the Arduino UNO SMD edition and I'm also quiet new to electronics in general. Recently I wanted to try out this tutorial https://www.arduino.cc/en/Tutorial/Button and I ...
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1answer
27 views

Button isn't working properly

I am new in arduino trying to make race game. My problem is that my button (all buttons) is working sometimes and sometimes not. I am pretty sure that it's because of my code. Could you please help me ...
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1answer
70 views

Coding force sensitive resistor to give output based on time used?

I have a basic set up of having a force sensitive resistor being used to power an LED as can be seen below. I am wondering how I can code it so that the LED is lit after a pressure has been applied to ...
6
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1answer
7k views

Resistor pull-ups for ESP8266

I'm using 4.7kOhm resistor as pullups for GPIOs 2,0,2,16, CH_PD and RESET, and also 4.7kOhm pulldown for GPIO 15. The ESP8266 boots and works fine. Would it be okay for a long shot? Should I use ...
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3answers
106 views

What is the most Inputs on An analog Pin with a specified Accuracy on the Resistors Used?

I am asking about the technique were switches and resistors in series are used on the analog pin, so it creates a voltage divider when one of the switches is pressed, it a well known technique it is ...
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1answer
416 views

4-20 milliamp to volts to pressure maths

I am measuring pressure in bars from OsiSense™ XMLP pressure sensor (4-20 milliamp) on a arduino uno. When the machine im measuring pressure on is switched off the reading is 0v as expected. When the ...
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1answer
63 views

Powering arduino sensors - what resistor should I use?

Recently I have asked a question, why my sensors do not work on external power supply (link). I have found out, that I was limiting the current too much with the resistors. I have tried using two ...
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1answer
7k views

Reading 4 to 20ma pressure sensor using uno

I have a OsiSense™ XMLP pressure sensor that I want to read from my Arduino uno. This is the circuit I am looking at building for measure 4 to 20 milliamp. I've read online to find out how to build ...
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1answer
221 views

In a circuit with a switch and a pull-down resistor, why does the high impedance of the input not discourage current from flowing into pin?

I'm a beginner to Arduino and circuits. I've spent the last couple hours hung up on the concept of how current flows through switches and pull-down resistors, having read every thread and watched ...
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0answers
1k views

Using Capacitive Sensing Library with a 74HC4067 multiplexer

I'm trying to use the Capacitive Sensing Library by Paul Badger in conjunction with one or more 74HC4067 multiplexers to achieve a lot of capacitive touch inputs. I came across this youtube video ...
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2answers
6k views

Purpose of this resistor in Arduino Nano schematic

I was looking at the Arduino Nano's schematic and noticed a resistor that seems to be pointless (RP2C on this picture). Also there is numbers 6 and 3 on it, does it mean that resistor is connected to ...
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1answer
260 views

How do I pull up D1-D6 using 10k ohm resistors?

I'm using push buttons to control CR servos (button1=turn CW; button2=turn CCW). How do I pull up D1-D6 and what does that do exactly? I can't find a tutorial that explains it well enough how to use ...
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2answers
3k views

8Ω speaker, what resistor values to use?

I want to connect 2 speakers of 8 ohm to 2 (different) pins of the Arduino. However, for this example one speaker is enough. I came across a lot of circuits without or with a single resistor which on ...
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3answers
3k views

How to select which resistor is required for my curcuit to reduce voltage

I am trying to connect arduino and esp8266 as like this I know arduino runs at 5V and RX of ESP8266 should not have voltage more than 3.5V. If you see my diagram there voltage is large than need on ...
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1answer
825 views

Understanding schematics: resistors attached to Attiny85 pins V-USB

I'm currently trying to create my own Attiny85 usb thumb(to mimic an joystick). I understand that I have to limit the voltage on the attiny's pins that are connected to the D+/- pins from the usb. In ...
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1answer
120 views

Resistors/capacitor used in connecting 23LC1024 SRAM 1 Mbit

Yesterday I received by 23LC1024 SRAM with 1 Mbit memory. I tried to search for some libraries and ways how to connect it. So I searched around on internet first for the connections and saw some ...
2
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3answers
7k views

What difference makes resistance of thermistors?

Following this thermistor tutorial i used 1k thermistors (and resistors) instead of 100k as in video. What difference does it make? What about 10k thermistors? Is it good idea to use 1k/10k/100k ...
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5answers
7k views

Stop Led's from blinking

My code: // Pin 13 has a LED connected on most Arduino boards. // give it a name: int led = 13; const int buttonPin = 2; // the setup routine runs once when you press reset: void setup() { // ...
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2answers
920 views

Newbie Arduino DC motor problem

So I am new to Arduino and new to electronics in general. I've looked up a few tutorials and they all have a simple early tutorial that turns on a DC motor and turns it off again. Something like this: ...
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1answer
42 views

Arduino Starter Kit - firmly wiring longer parts

I am getting started with project 01 on the Arduino starter kit. I'm facing an issue when wiring parts with long ends e.g. led & resistor. To make the simple circuit with led, resistor & ...
2
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1answer
105 views

What is micro C in a circuit diagram?

This is probably a simple question but I am a beginner with these things. What does the micro C part of the circuit diagram mean? The diagram is from the datasheet of the tssp77038 IR receiver. Does ...
3
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1answer
634 views

Getting the DS18B20 detected and temperature read

I'm quite new with the electronics part of Arduino, but I thought that this was the basic way to get the DS18B20 temperature device hooked up. However, I can't detect it in my program using OneWire ...
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0answers
304 views

How to use Honeywell NBP Series Sensor with Arduino

I am trying to use a HONEYWELL NBPDANN100PAUNV Pressure Sensor. I found an example here http://www.circuitstoday.com/interfacing-pressure-sensor-arduino As this example says as instrumentation ...
3
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3answers
230 views

Unexpected Delay Between For Loops

I made some arduino code for leds that blink down a row and then back again, but when the program is run, there is an approximately 2 second delay in between the first for loop and the second. This is ...
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1answer
918 views

Formula for current through shift register

Hi I am programmer that just started learning electronics and Arduino. I built this simple circuit on Autodesk Circuits earlier. Originally I used 220 ohm resistors. Then when I ran the simulation ...
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1answer
54 views

Switch between ntc resistor sensors time based for other device

We have a heating system that uses an ntc resistor to measure water temperature. I would like to replace that ntc resistor by a fixed one (low enough to disable heating) temporary on a 5 minute ...
0
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2answers
1k views

Multiple I2C BREAKOUTS with pull-up resistors doesn't work [UPDATE]

[UPDATE] Now it works fine but the as soon as I add the GY-521 module (hardware not software), it starts sending me crapy info Project uses: Arduino Pro Mini as brain FTDI as a programmer GY-521 ...
2
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1answer
126 views

Self made microphone burns Arduino

I'm very new to electrical engineering and I'm trying to read microphone input with Arduino Nano. I've made a separate microphone module (based on this example) and plugged it into Arduino like this: ...