Questions tagged [capacitors]

A device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator.

Filter by
Sorted by
Tagged with
2 votes
3 answers
374 views

Problem with messuring capacitance with 50 Arduinos connected by I²C

I want to measure changes in capacitance over time. One Arduino is used per capacitance sensor. There is one anode per Arduino and a total of one common cathode (see the picture) With four Arduinos ...
user avatar
  • 21
2 votes
1 answer
37 views

Touch Sensor and Potentiometer - Need some help

I'm using an Arduino Nano with a capacitive touch sensor and a potentiometer. I'm trying to get my code to differentiate between three different program states. One is when my touch sensor is NOT ...
user avatar
1 vote
1 answer
45 views

Pulsing 3v into a capacitor to create custom Voltages

I was wondering if it is possible to create diffrent voltages by just pulsing power into a capacitor, Im using an esp32 which can only output 3v or nothing on its GPIO pins, and i need to make it ...
user avatar
2 votes
0 answers
89 views

Arduino pro mini resetting itself

I am working on a brushed motor quadcopter using Arduino pro mini. Every time I try to throttle, the Arduino gets reset by itself (motors start to spin but they will be turned off in 2 sec). I have ...
user avatar
1 vote
0 answers
152 views

Debouncing interrupt using capacitor

I'm currently working on nodeMCU and need to use interrupt pin. I find out there are bouncing problem when using interrupt thus i use capacitor 100uF to solve this problem. The question is by using ...
user avatar
2 votes
1 answer
179 views

Arduino Mega Clone CH340G Capacitor Values

I'm making my own Arduino Mega board with ATmega2560-16AU and CH340G. Jump to the end of the post to find the real question. I have already ordered a PCB before and it didn't work when I soldered ...
user avatar
  • 41
2 votes
2 answers
153 views

How safely write to SD or Eeprom on Arduino power off

I want to constantly store data to sd. But how I make sure data is not corrupted on moment of power off? I think I could add small capacitor on 5V and check when voltage drops, so I would stop data ...
user avatar
  • 127
2 votes
0 answers
73 views

Reliably using analogRead as a compact digitalRead

My goal is to reduce pins being used for micro-controllers with limited pins, or projects requiring a few different digital input values. How I intend to do so is by using ADC pins to gather four ...
user avatar
  • 167
0 votes
1 answer
106 views

USB disconnects when using a capacitor

I'm currently working with some WS2812B LEDs and tried out adding a capacitor to be safe from voltage spikes (was recommended by Adafruit). I noticed that a soon as I connect a capacitor between 5V ...
user avatar
0 votes
1 answer
765 views

Placing decoupling capacitors when building an Arduino PCB with Atmega328-PU

I have previously asked this question: Custom build of arduino on a pcb And thanks to the answer by Majenco I have learned that my circuit works a lot better when adding a capacitor. For example I ...
user avatar
  • 898
0 votes
1 answer
88 views

Please help me read this Schematic Diagram

So, i'm trying to build an Obstacle Avoiding Robot by refering this site "Robot Obstacle Avoiding Car On the website they have provided with very poor Circuit Diagram. Please help me read the ...
user avatar
-3 votes
1 answer
233 views

Serial communication stops when powered with batteries?

Circuit explanation- Arduino Uno connected to multiple sensors and to 16 x 2 LCD. Uno's TX pin to ESP-01 RX pin. Uno has been programmed to read values from sensors and display them on LCD along ...
user avatar
  • 49
1 vote
2 answers
414 views

How to safely remove arduino nano from breadboard? [closed]

I did some prototyping with arduino nano in breadboard. And then after i done with the design, I was gonna implement it in a printed pcb so i need to remove the nano from breadboard. And this is when ...
user avatar
  • 13
-2 votes
1 answer
416 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 ...
user avatar
  • 1
4 votes
2 answers
4k views

Why is AREF connected to a capacitor in the Arduino Pro Mini Schematic?

I'm currently looking at the Arduino Pro Mini schematic and have noticed that the pin AREF (analogue reference) is connected to a 0.1uF capacitor as shown below: I have done some research and read ...
user avatar
1 vote
0 answers
211 views

Testing a capacitor with a nodeMUC Lolin V3

Apparently it's possible to test the capacitance of a capacitor with an arduino. In this thread, someone tries to do the same on a NodeMCU but the conclusion is that it's enough to get the change in ...
user avatar
  • 111
0 votes
1 answer
105 views

How would I go about powering addressable RGB LED light strip? [Arduino Nano] [closed]

The addressable RGB LED I have is WS2812B. I plan on controlling the LEDs via an Arduino nano. I have a total of 188 LEDs to supply power to. Would I require anything between the addressable RGB LED ...
user avatar
0 votes
1 answer
173 views

How can I power a NeoPixel ring and strip through Arduino MKR1000?

I currently have a MKR1000 which is connected to 1 ring with 8 neopixels, 1 strip with 20 neopixels, 1 microwave sensor, 1 speaker, 1 rotary encoder. I am running the NeoPixel positive and negatives ...
user avatar
0 votes
1 answer
391 views

Capacitors, Arduinos and Saving Data

In short, I have programmed and wired a speed/odometer and all is working well. However, I need to save data from the components/sensors once a power button is pressed, which has led me down the road ...
user avatar
1 vote
1 answer
2k views

How to keep a pin LOW for a small amount of time after pushing a button and while device is booting?

Context I keep the board in deepsleep mode and want to wake it with different buttons. I need to know which button has been pushed on boot. The board is immediately put back in deepsleep mode ...
user avatar
  • 159
-1 votes
1 answer
2k views

Reading values from TTP229 capacitive touch sensor on arduino

I would like to be able to read the raw capacitive sensor values from a TTP229 chip through i2c in Arduino. I have one of these breakout boards to play with : My goal is to get values similar to ...
user avatar
4 votes
4 answers
2k views

Is the ShiftOut tutorial on the official Arduino website really wrong regarding the capacitor?

I'm talking about this tutorial "Serial to Parallel Shifting-Out with a 74HC595" from the official Arduino website. It provides the following schematic: I've read a couple of times now, that the ...
user avatar
  • 77
1 vote
2 answers
3k views

Purpose of capacitors in this project

I'm currently working on a project where I am making a wheeled robot using the Hack-e-bot library on the arduino. The circuit board which I have planned to put together through soldering will ...
user avatar
  • 231
1 vote
1 answer
384 views

Decoupling cap for self-powered LED matrix and LED strip

Should I add a decoupling capacitor to my RGB 16x32 LED matrix powered directly via the 5V pin? When I display a spectrogram, the current load is fluctuating quickly in the 100-250 mA range (on ...
user avatar
  • 183
1 vote
2 answers
4k views

Correct Capacitors to use with L7805 Voltage Regulator

I am making my own arduino. I am in the process of hooking up power to the Atmega328. In both these articles they use the L7805 voltage regulator with two 10uF capacitors. https://www.arduino.cc/en/...
user avatar
  • 125
0 votes
1 answer
204 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 ...
user avatar