Arduino newsletter

Top new questions this week:

Reasons why it is not OK to connect a relay directly from an Arduino digital pin

After looking into various schematics on controlling a relay via an Arduino, I have noticed that, most of the time, transistors are used to switch the separate supply into the relay coil rather than ...

arduino-uno relay safety

asked by Rej Averion 5 votes answered by Russell McMahon 6 votes

Trouble with sleep mode and interrupts

Context I am building a small battery powered counting device. As with many other projects like this, saving power is critical. I am therefore trying to utilise the sleep mode wherever possible. This ...

interrupt sleep

asked by Dan Evans 2 votes

Keyboard.print() skips keys

I'm playing with the Arduino Leonardo Keyboard.print() command, but I'm facing a annoying problem: When I print a double quote, it will not appear and also will make to disappear the next character ...

usb arduino-leonardo keyboard atmega32u4

asked by Helio 2 votes answered by Majenko 4 votes

Arduino Pro Mini lower BOD problem

I am planing to build a project where an arduino pro mini 3.3V runs on 2 aa batteries. The standard brown out detection shuts it down at about 2.7/2.8V where it could run on lower voltages too. So I ...

arduino-pro-mini avrdude isp arduinoisp

asked by CodeO 2 votes

Passing a static array to a function

I have a functon that creates a instance of KeyReport and I want to fill statically the KeyReport.keys array. I'm new in the Arduino world so I'll put a example to explain it better: void ...

programming c++

asked by Helio 2 votes answered by Majenko 2 votes

How to program an offbrand arduino uno?

So I recently bought this off brand arduino uno from betemcu.cn. it says its r3 compatible. Can I program this thing with the arduino coder or do I need to use something else? whenever I try ...

sketch

asked by Corey Selby 2 votes answered by Russell McMahon 3 votes

Suggest some highly sensitive temperature sensor

Currently I am using DHT11 in my project, but its not very sensitive, it is quite slow in detecting temperature changes. What sensor could I use that will be more sensitive?

temperature-sensor

asked by j-man-noob 1 vote answered by Butzke 0 votes

Greatest hits from previous weeks:

How to check my Arduino board is working or dead?

When you have a board in your hand but you don't know is it working or not, how to verify if it's working or dead?

arduino-uno testing

asked by Hardik Thaker 9 votes answered by Hardik Thaker 9 votes

What is the work of pulseIn?

I have code for an ultrasonic sensor which I found from a site. Here is the code: #define trigPin 12 #define echoPin 13 void setup() { Serial.begin (9600); pinMode(trigPin, OUTPUT); ...

arduino-uno sensors pulsein

asked by shajib0o 5 votes answered by sachleen 5 votes

Can you answer these?

array shuffler if-then and output question

I have an array shuffler code right 1) How do I use an if-then statement to say if all buttons pressed in order, then LEDs blink 3 times?Thank you. code: void setup() {} void loop() { int ...

arduino-uno arduino-ide

asked by errr 1 vote

Arduino UNO "MEM CHECK FAIL" error

Just followed a tutorial on how to set up ESP8266 with my Arduino Uno R3. I have a serial connection and get a response of the arduino but im stuck now at chapter "first commands". I have ...

arduino-uno

asked by arduinolino 1 vote

Problems connecting reliable using HC-05

I currently try to connect an Arduino Micro/Leonardo/32u4 to an ELM327 bluetooth dongle using a HC-05-bluetooth-shield from iTeadStudio. The basic AT-command communication works, but I haven't found ...

bluetooth hc-05

asked by Thomas S. 1 vote