Arduino Stack Exchange
Arduino Stack Exchange

Most Popular

more tags
1500 questions
9
votes
3 answers

I2C LCD Serial Interface Board not displaying text (wrong pins?)

I have a 1602 LCD screen that works fine on its own. However I wanted to free some pins by using an I2C / IIC LCD controller I purchased separately. While the controller seems to be communicating with my Arduino UNO on the right address, I cannot…
Bort
  • 397
  • 2
  • 6
  • 18
9
votes
4 answers

Is SoftwareSerial left out for the ATTiny85/84?

I want to use SoftwareSerial with my ATTiny85 and when I google it several projects claim that they are using it... I downloaded the hardware from https://code.google.com/p/arduino-tiny/, but when I try to add SoftwareSerial and compile I get: fatal…
Jason94
  • 303
  • 1
  • 5
  • 11
9
votes
2 answers

How can I sense very high temperatures with Arduino?

I've seen many temperature sensors, but the highest temperature they go up to is 125 degrees C (257 degrees F). I want to reach higher temperatures than that. I'm thinking about rigging up a closed loop sensor for my soldering iron (for a convenient…
Anonymous Penguin
  • 6,365
  • 10
  • 34
  • 62
9
votes
3 answers

Grove sensors without a Grove shield

There exists a large variety of sensors in the Grove System. Usually these are accessed via a special shield (Grove base shield). Can I access these sensor directly without a shield. In particular I am interested in using them with an Arduino Pro…
A.Schulz
  • 467
  • 1
  • 6
  • 9
9
votes
3 answers

How to turn off or stop Access Point network in ESP8266?

I've created a code for ESP8266 12E with Arduino IDE, in which it'll operate as "Station Mode" or "Access Point Mode" on Wifi, depending on the situation. Everything works fine except when device was configured as Access Point, even when I turn off…
wBB
  • 293
  • 1
  • 2
  • 8
9
votes
2 answers

How to update a variable in an ISR using Timers

I'm trying to check the frequency of Timer3 using a counter. The value of the counter, declared as volatile, is incremented in the ISR and every second the sum is shown in the main loop and the value reset to zero. The timer has been set up…
UserK
  • 559
  • 1
  • 11
  • 24
9
votes
3 answers

Creating formatted String (including floats) in Arduino-compatible C++

I'm using a Mega2560 and a generic SSD1306 OLED display with the Adafruit_SSD1306 (and by extension, Adafruit_gfx) library. I need to print a bunch of float values (ranging between 30.0 and 99.9) to the display with exactly one decimal place of…
Bitbang3r
  • 561
  • 1
  • 3
  • 14
9
votes
2 answers

memory usage "dos and don'ts"

Though I've written C/C++ code for a long time, the unseen limitations on how memory was consumed on various MCU and SOC programming platforms have often tripped me up. As I'm about to build up code for my first large project for my NANO boards,…
Randy
  • 407
  • 3
  • 13
9
votes
1 answer

Resistor pull-ups for ESP8266

I'm using 4.7kOhm resistor as pullups for GPIOs 2,0,2,16, CH_PD and RESET, and also 4.7kOhm pulldown for GPIO 15. The ESP8266 boots and works fine. Would it be okay for a long shot? Should I use 10kOhm instead of 4.7kOhm?
JFetz2191
  • 155
  • 1
  • 2
  • 7
9
votes
1 answer

Why connect a diode between the reset pin of Arduino and 555 timer?

I am trying to create a watchdog timer using 555 IC and I am following this. I do not understand why a 1N4148 diode is connected between the reset pin of Arduino and the output of the 555 timer. As far as I understand, the reset pin of the Arduino…
bukke hari prasad
  • 159
  • 1
  • 1
  • 6
9
votes
2 answers

How can I pass an object as a parameter to a function?

I am making a tiny game, and want to store high-scores. I made a Highscore-class in the top of the sketch file, like this: class Highscore { public: String name; int score; String toString() { return this->name + " - " + (String)score; …
krystah
  • 195
  • 1
  • 2
  • 6
9
votes
1 answer

SPI Arduino Due conflict with pinMode(), bug?

Consider the following minimal example, where I set pinMode before calling SPI functions: #include void setup() { pinMode(10, OUTPUT); SPI.begin(10); SPI.setDataMode(10,SPI_MODE1); } void loop() { delay(1000); …
newandlost
  • 223
  • 1
  • 4
9
votes
9 answers

Best way to determine if a 5 gallon water jug is getting empty

I have an espresso machine that gets its water from one of those 5 gallon blue water bottles (I would plumb it, but our water here is WAAAAY too hard). If I ever accidentally let the bottle run out of water, the rotary pump in the espresso machine…
synic
  • 203
  • 2
  • 6
9
votes
3 answers

delay(time); vs if(millis()-previous>time); and drift

Going through an old project, I had code on two Arduino Due that looked like this void loop() { foo(); delay(time); } taking to heart the majority of literature on using delay(); I recoded this as void loop() { static unsigned long PrevTime; …
ATE-ENGE
  • 941
  • 3
  • 19
  • 32
9
votes
4 answers

How do functions outside of void loop work?

I am used to Arduino sketches with a void setup() part that runs once, and a void loop() part that keeps looping. What happens when you have void functions outside of the main void loop()? Will these all keep looping in parallel or do they run one…
Blue7
  • 245
  • 3
  • 4
  • 8
1 2 3
…
99 100