Passive electronic component which reduces current flow in a circuit, dissipating power as heat.
-1
votes
0answers
34 views
Teensy 3.2: Unable To Read Voltage Change Across Variable Resistor (Not Potentiometer)
Code:
//constants
const int analogPin = A9; // pin that the sensor is attached to
const int ledPin = 13; // pin that the LED is attached to
const int Threshold = 920; //.2 milliamps
void ...
1
vote
1answer
36 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 ...
0
votes
1answer
22 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
votes
2answers
55 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 ...
3
votes
1answer
30 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:
...
0
votes
3answers
129 views
Why have resistor at end of circuit cycle if GND dissipates final energy?
The first challenge on the Arduino Uno manual is to make a closed circuit with a button and LED. The voltage is provided by the 5V pin (non IO), connected by wire to (+) on the bus (breadboard). The ...
0
votes
1answer
40 views
digitalPin giving lower voltage than Vcc
I am using an ATTINY88 for a project that requires to turn on an LED. Right now I am using pin PA1(ADC7/PCINT25). I noted, however, that when the pin is ON, I get about half the voltage that is ...
0
votes
1answer
11 views
How to encode resistance change (reed) for Arduino?
I have a water counter which switches reed on each 10 liters of water. I would like to count these values with Arduino.
I wrote a program which counts changes from analog input and connected counter ...
0
votes
2answers
51 views
Use LDR with 220 ohm resistor
I have read many tutorials on LDR(Light dependent resistor) with Arduino which includes a 10 kilo ohm resistor but can i use it with 220 ohm resistor or even without resistor.
0
votes
3answers
42 views
How can I understand the circuit diagram for Arduino Starter Kit Project 4?
I have acquired the arduino starter kit project book, and the explanations seem at times confusing and difficult to understand.
Concerning the above circuit diagram, the book states (I am ...
0
votes
1answer
35 views
How to 'label' module using electric techniques
I am in a project where it makes set of 'modules(set of separate circuits that will work as a sensor when connected to the board' that would be connected to Arduino Mega.
Currently, I'm planning to ...
-1
votes
1answer
28 views
Photoresistor Switch
How would I use a photoresistor like a switch. My issue is it is always bleeding out a little bit of power and always on. Is there a way to connect it to a digital pin and when a resistance of xxx is ...
3
votes
2answers
148 views
What is the minimum wattage of resistors for breadboarding with Arduino Uno?
I'd like to buy new resistors for breadboarding with my Arduino Uno. There are 0.25W, 0.4W, 0.6W, 1W, 2W, 3W, 5W, 10W resistors in the shop. What is the most suitable for this operation?
1
vote
1answer
68 views
Diode lights generate false interruptions
I have spent quite a considerable time debugging my code that was triggering false interruptions. I have found out that the source of the error were the diode lights (on the picture). I would like to ...
0
votes
0answers
70 views
Arduino does not work when using resistors
I have witnessed a strange behavior of my arduino uno R3.
Each time I wire up a resistor into the breadboard, it simply does not work.
for instance, I wired up an LED + 1Kohm resistor to the 5V and ...
0
votes
1answer
117 views
Driving multiple LED arrays with shift registers
The project I'm building requires multiple LED arrays. I'm going to wire these LEDs in parallel and then connect the arrays to individual pins on a shift register. In addition to the LEDs running in ...
0
votes
3answers
89 views
does INPUT_PULLUP uses power?
When using a digital pin as input, one has the option of using the internal arduino resistor, which is connected to VCC; that is setting the digital pin as INPUT_PULLUP, and then the pin reads HIGH. ...
0
votes
1answer
419 views
10k ohm Potentiometer vs 10k ohm Resistor on LCD Display
I'm trying to use a LCD Display with my Arduino, but I don't have a potentiometer and all of the guides I find always require one, usually a 10k ohm potentiometer.
The point is that I'm not very good ...
2
votes
1answer
96 views
what is the importance of the resistors that connect to push buttons ? can i replace them by wires?
Please, iam a junior in arduino and i want to know what is the importance of the resistors that connect to push buttons? can i replace them by wires?
thanks in advance.
0
votes
2answers
2k views
Can I supply the board's 3.3V directly to the AREF pin?
Short dumb question: can I connect the 3.3V pin and the analog reference pin (AREF) directly?
I've heard mentions of a 32K internal resistor but I'm not willing to risk a short circuit without ...
0
votes
1answer
65 views
Use of Resistor in PinWheel Exercise
I'm working on project 9 of the Arduino starter kit - the motorized pinwheel.
Here is the schematic:
(if img not showing: https://goo.gl/tqZmKD)
My question is, why is the 10k resistor needed after ...
3
votes
2answers
797 views
Why all blink tutorials use 330 ohm resistor
When I do the led calculation I found 150 ohm resistor is enough for 3mm red led. If so why all arduino tutorials, like this one, are suggesting 330 ohm resistor?
I assume V = 5 Volt, diode forward ...
0
votes
2answers
198 views
How to interface DS1801 digital resistor with Arduino DUE SPI interface? What clock rate so use?
I am trying to program a digital resistor and set it's wiper resistance. The general circuit looks a little like this where "pot" represents the Maxim DS1801 digital resistor and DUE is, of-course the ...
0
votes
0answers
27 views
Why is a resistor to GND needed for a switch that is open? [duplicate]
I don't understand the books explanation for why a 10k resistor is needed for an open switch to write LOW to a digital pin. I thought no voltage is LOW anyway. Can someone explain in a little more ...
0
votes
1answer
288 views
Lighting 5 leds…the last one lit is always dim
I have a simple project with a close deadline.
I am trying to light up 5 LEDs as part of the project. The first 4 light up in sequence fine, and if I light up just the last one it lights up fine, but ...
2
votes
2answers
150 views
Source power with 2 V and LED with forward voltage of 2 V
I have a source power with 2 V and 100mA. I have an LED that has a forward voltage of 2 V and a max current of 20mA.
Should I use a resistor to reduce the current? I see many formulas in the internet ...
0
votes
1answer
96 views
How much current and voltage has my resistor + LED
I have a very simple circuit: 5v -> LED (5mm, forward voltage of 2 V and max. current of 20mA) -> 1k ohm resistor -> GND.
I want to know how much current is flowing in my circuit. I am using this ...
0
votes
1answer
90 views
how to calculate correct resistor value to use with LEDs Potentiometer and other devices?
I have been following http://arduino.cc/en/Tutorial/Fade to fade and LED. But I don't know why they are using a 220 Ohm resistor.
According to Ohms law if LED is of 2.2 V and it runs on 0.025Amps and ...
1
vote
2answers
86 views
Which side should I connect the resistor on?
I understand that when connecting an LED and a resistor in series; the resistor can be placed on any side of the LED as the current will remain same in a series connection. Please correct me if I'm ...
1
vote
2answers
88 views
What does the datasheet information for a switch mean?
I'm clueless when it comes to the information on datasheets for switches. When I see a datasheet for LEDs or servos, I'm used to seeing a fairly straightforward call out for the required volts and ...
5
votes
2answers
451 views
Performance of internal vs external resistors
Is there any significant performance trade-off between buttons wired with the internal vs external pull-up/down resistors? I see a lot of tutorials demonstrating the use of external resistors when ...
1
vote
4answers
712 views
Importance of resistor
I'm new to Arduino and also new to electronics. I'm following the tutorial here. I'm not understanding the importance of the resistor in this schematic diagram. Can someone please help me on this?
15
votes
2answers
2k views
Can two LEDs attached to different pins share their resistor?
I'm designing an Arduino style board with built-in LEDs for several of the pins. To simplify assembly of the board and save on components, I was wondering whether it would be safe for those LEDs to ...
-1
votes
1answer
2k views
Sensors and leds. This need resistors? and how?
I have a project with leds and sensors, this is my first project in Arduino and I want to know if it need resistors and how and where?
I use 16-Bit I/O Expander MCP23017 for leds and multiplexer ...
1
vote
3answers
2k views
Can I change VCC pin to 3.3V on a 5V Arduino Pro Micro?
I'm using a 5V Arduino Pro Micro (schematic).
For my project, I'm using the VCC pin to output power to an external device. I need VCC to output 3.3V to the external device. Can I open jumper SJ1 to ...
8
votes
3answers
1k views
Digital Read Serial tutorial - calculating the resistor value
The Arduino Digital Read Serial tutorial guides you through the wiring of a simple button. My questions are centered around the resistor.
Why is the resistor necessary?
I think I understand this, ...
0
votes
4answers
647 views
Setting a Pin to HIGH to simulate a button with a “pull up” resistor
in the below Fritzing diagram, I have a button that has a pull-up resistor, which when pressed, sets the GPIO Pin 23 to HIGH. On the Raspberry Pi, when the button is released, the GPIO goes LOW. The ...
5
votes
2answers
240 views
Use Higher Resistance Than Instructed in a Circuit
I'm following the "Get Started with Arduino" Guidebook, and I'm at the part where pulse width modulation (PWM) is discussed.
The instructions say to create a simple circuit with a breadboard, red ...
18
votes
2answers
2k views
What happens to the Arduino if you don't use a resistor with an LED?
Making a blinking light seems to be one of the most common beginner projects with Arduino. A typical approach is to connect an LED + resistor (in series) to an IO pin, and connect the other end to ...
