Linked Questions

1
vote
3answers
485 views

How can I connect an 8-relay board without using 8 digital pins? [duplicate]

I'm looking to connect an 8-relay board to an Arduino Uno. A board like this one. However, I don't really want to use up 8 digital outputs if I don't have to. Is there some intermediate circuitry I ...
1
vote
2answers
55 views

Upcoming Project [duplicate]

Hey guys I have a project that will require 20 I/O pins with serial communication from a computer to control each of the pins. I would like something as small as possible would a arduino micro or uno ...
1
vote
0answers
33 views

How can I use Arduino Analog Uno pins as Digital pins? [duplicate]

How can I use Arduino Uno Analog Pins as Digital pins, So that I can Attach more components like sensors to the Arduino? My 13 pins are preoccupied and I want more.
21
votes
2answers
9k views

Why can't I upload a sketch while other components/devices are connected to my Uno?

I wanted to make a fairly simple circuit which would flash a series of LEDs in sequence, using my Arduino Uno (more specifically, a SainSmart clone). I wrote my sketch and it compiled fine. After that,...
12
votes
3answers
94k views

Use all pins As digital I/O

Increase the number of digital pins There are many post that explain how to use more than just the standard pins on the various arduinos but none of them explain the limitations and the proplems ...
13
votes
3answers
29k views

How do I use I2C devices with Arduino?

I have a few useful I2C components, such as a 16-bit port expander (MCP23017), which I'd like to use in various projects. What do I need to do to make these work with Arduino? Will it work with any ...
0
votes
2answers
2k views

Increasing the numbers of I/O pins on Arduino Uno

I want to make a game of Tic-tac-toe using an Arduino, LEDs and bouncy buttons. Hence I need nine inputs and nine outputs. But you see that an Arduino only has 13 I/O pins. So is there a way I can use ...
2
votes
3answers
190 views

Direct 5V current based on analog signal

I would like to manage many LEDs from my Arduino - 12 or so - but I do not have the available digital pins to do this. Only one LED needs to be on at one time. Instead, I was hoping to control these ...
1
vote
2answers
267 views

Light up multiple LEDs with standard Arduino Uno

I am trying to find out if it is possible to light up multiple LEDs with a standard Arduino Uno. Say I have 500 LEDs and logically I give each one of them a number from 1 to 500. In my test scenario I'...
0
votes
2answers
299 views

Arduino UNO with CD4510 Counter

I am new in Arduino but I have experience in electronics. I was wondering how can I make a countdown timer using a CD4510 and an Arduino UNO. I know you would suggest that I should connect my seven ...