Arduino newsletter

Top new questions this week:

interrupting an interrupt

What should be expected if the code in the timer interrupt ISR does not finish before the interrupt is called again? For example Timer0 ISR(TIMER0_COMPA_vect){} on the Uno. This is for debugging ...

arduino-uno interrupt

asked by perigalacticon 6 votes answered by Gerben 8 votes

Arduino Uno VIN 2A

Trying to get started with the Arduino, so I'm trying to do something kinda simple. I'm following this tutorial: Build Your Own Dynamic Ambient Lighting For A Media Center However, I'm still confused ...

power current

asked by 1n9i9c7om 4 votes answered by Majenko 2 votes

How to connect Arduino to headphone jack?

I would like to connect a headphone jack to my Arduino and make it as an output. I mean I would simply send some simple beeps. I know that there is a breadboard friendly headphone jack, but I don't ...

arduino-uno audio sound

asked by Leah 4 votes answered by st2000 3 votes

Arduino - stepper motor wrong steps number

I just bought a new stepper motor ( 400 steps for revolution, 0.9°/step) and I would like make a turn of 180° by 200 steps, but it doesn't work as aspected. It looks like the motor needs only 110 ...

motor stepper l298n

asked by Victor Dika 3 votes answered by ChatterOne -3 votes

Arduino MCP23S17 I/O Expander (SPI)

I found this post and I am having almost the exact same issue. Nick Gammon (the god of arduino) has an excellent answer but I can't for the life of me implement it myself. I am not an advanced user ...

arduino-uno pins

asked by enterprisingsoul 2 votes

Circuit with buzzer not working :(

so I have a circuit with a buzzer and a resistor: This circuit should be working, but for some reason the buzzer doesn't sound. I pushed the buzzer into the breadboard as hard as I could, I put the ...

arduino-uno buzzer

asked by Max 2 votes answered by Sanu - Open Maker 4 votes

Arduino program does not start when plugged in

I am having trouble with my Arduino Mega with getting the program to start when the Arduino is plugged into a computer via USB. All that happens is the LED turns on and stays on. The device does not ...

arduino-mega usb

asked by vcapra1 2 votes

Greatest hits from previous weeks:

error: redefinition of ' '

When I am trying to compile the following code, int delayTime = 1; int charBreak = 2.1; #include <MemoryFree.h> int rled1 = 1; int rled2 = 2; int rled3 = 3; int rled4 = 4; int rled5 = 5; int ...

arduino-uno

asked by user3826856 2 votes answered by Chris Stratton 3 votes

How to toggle LED on button press?

I want to have a LED turn on when I push a button and go off when I push the button a second time. This code doesn't work: const int buttonPin = 4; const int motorPin = 10; const int ledPin = ...

button

asked by Julian Köberle 1 vote answered by Peter R. Bloomfield 5 votes

Can you answer these?

POST data from Arduino to website

I am working on a project where I am trying to send data using HTTP and POST method from my Arduino Mega2560 to a website which I host on localhost. I am living to a students' accommodation and thus, ...

web-server networking http

asked by user2052363 1 vote

Issues graduating to AVR-C

I'm trying to make the transition from coding in the arduino language to AVR-C, but I'm having some issues with my microcontrollers. I don't have an ISP, so I'm using one of my Arudino UNOs with the ...

c atmega328 avr avrdude arduinoisp

asked by Isak 2 votes

How come my code does not wait for a specific time before going into an if statement?

I have an HC-SR04 attached to a servo. When the 90 degree reading is less than 30 cm, I want the motor to take 2 seconds to turn to 130 degrees, get a measurement on the right, and turn back to 90 ...

arduino-mega servo timers millis hc-sr04

asked by Nick Solonko 1 vote