Most Popular
1500 questions
4
votes
2 answers
How to make an Arduino act reliably as an SPI slave?
I want two Arduino Nanos to communicate with each other using SPI, ideally at around 2MHz or faster.
I have two standard Nanos running at 16MHz on 5V.
The master uses SPI.transfer() to send an array across the wire.¹ For ease of troubleshooting,…
Infinity Computers
- 71
- 7
4
votes
1 answer
How to determine when a sensor's output signal changes significantly?
Starting with an analog signal from any sensor, how do I automatically determine if there is a real signal change or a reset? Below is the sample code that better explains my goal:
value = sensorRead();
if (millis() > t + 1000) {
value_old =…
boromyr
- 43
- 3
4
votes
1 answer
Arduino Array Scope with SPI
when I try the following code the SPI works correctly (see oscilloscope plot)
#include
void setup() {
SPI.begin();
}
void loop() {
SPI.beginTransaction(SPISettings(100000, MSBFIRST, SPI_MODE3));
byte a[] = {0xC,0xFF,0xFF,0xFF};
…
user1441016
- 53
- 3
4
votes
2 answers
Controlling a 5V fan and ultrasonic fogger with an arduino - do I need an external power supply?
I know the whole controlling a fan with an arduino thing is getting old, but somehow I still don't get it to work. Tried to answer it based on other questions but I am too much of a newbie to extrapolate the info there to my specific problem.
For my…
crabdance
- 43
- 2
4
votes
1 answer
How do I listen for a sound that matches a pre-recorded sound?
I'm working on a project that uses an Arduino Uno to listen for a bell ring and then uploads to a web server the exact time the bell was rung using a WiFi Shield.
I want to know how I can listen for the bell ring (a three second long high pitch…
Ben
- 41
- 1
- 3
4
votes
1 answer
Random access to SD card using SD.h or another library (ESP32)
I'm trying to use a SD card with my ESP32 in order to save some variables in a txt file. Each variable uses 1 byte, so they can be represented by an 8 bit extended ASCII character.
The issue is it seems that the SD.h library has only 3 open modes…
AlexSp3
- 203
- 1
- 7
4
votes
1 answer
Acrylic enclosure for Arduino
I've been browsing Aliexpress and eBay for decent Arduino enclusures, but I've found out they are even pricier then boards themselves.
Then I've realized that there are multiple firms that offer cheap laser cutting - I can buy 1 sq.m acrylic sheet…
Alexander
- 101
- 1
- 5
4
votes
1 answer
Is there an Arduino simulator that runs on Mac OS X?
I need to simulate my Arduino project with other circuit components before implementing the project. Is there a decent simulator that runs on Mac platform?
M.Medhat
- 49
- 1
- 2
- 2
4
votes
1 answer
Arduino ESP8266WebServer hangs after a while but responds pings
I have an ESP8266 module that I use to be able to power on three computers if they are off. The ESP8266WebServer has what I needed to have a POST method rather than a simpler GET one since I am sending a password and I want that little extra…
Elder
- 41
- 2
4
votes
3 answers
Stable frequency generation
I'm trying to work out the best way to generate a stable frequency with my Uno R3
I'm using interrupts to generate an approximately 40KHz frequency which drives some ICs/MOSFETs to effectively generate 40KHz AC which powers a transducer.
I need to…
Ramrod
- 187
- 1
- 1
- 5
4
votes
5 answers
Why use a module rather than sensor directly?
I'm trying to understand when one would use an Arduino module rather than directly a sensor.
Here's an example to contextualize my question: I need to use a Hall sensor to measure the number of rotations per minute of a magnet mounted on a computer…
Andrea
- 141
- 3
4
votes
1 answer
Arduino Uno freezes for unknown reason during code execution
I am struggeling with a behaviour of my Arduino I do not fully understand.
Long story short:
When starting the communication over I2C the Arduino freezes. In my opinion during the "Wire.write()" command.
Long story and background:
I want to connect…
IceCreamToast
- 43
- 4
4
votes
1 answer
Value of the counter collide on my lcd while decreasing. How can I remove it?
#include
LiquidCrystal lcd(12,11,5,4,3,2);
int visitor=0; //variable for counting visitor number
unsigned long timer_1,timer_2; //variables for recording time for ir_1 and ir_2
void setup() {
lcd.begin(20,4);
…
Rappy Saha
- 43
- 7
4
votes
4 answers
Bi-directional UART communication on single data wire, possible?
The nano is inside of the house, and the pro mini is outside of the house. I want to send/receive text between them. The communication will be always nano sending text to mini, and then mini sending text to pro in response. There will be no case…
Damn Vegetables
- 357
- 2
- 9
4
votes
1 answer
3th time blown à Nano every
Like subject all ready telling you, I blew up my 3th Nano every.
I mounted them on a perf board, soldered with 99% tin 1.0mm and a Flux, cleaned with flux remover, etc... When I then power them up through USB I have a short on pin 29 and 30 (Vin…
Joeri VA
- 49
- 2