C is a procedural programming language which is widely used in embedded systems. PLEASE NOTE: Arduino is typically programmed in C++, not C.
0
votes
2answers
52 views
What is the opposite of this data operation?
If I store in an array a double-value in this format, in which format I should be able to read the same double out?
double myDouble = 12.123456;
byte myArray[] = {0x00, 0x00, 0x00, 0x00};
myArray[0] ...
0
votes
1answer
19 views
Showing chronometer on PC controlling the begining and end of time by Arduino
I'm really new on this Arduino thing, so I don't know whether what I'm gona ask is feasible or not.
I'd like to make a chronometer in the computer but the controlling button (beginning and end of ...
1
vote
0answers
41 views
One of my my buttons is interfering with the other (i think)
So for school i have to make a code for my arduino, that let's me turn 4 led's on and off (as an input) with 2 buttons (one to select the led, one to toggle the led), run the inputs trough a logic ...
0
votes
1answer
34 views
Setting the sampling rate for timer interrupt
I had performance problems with the data acquisition and after some reading on the web, someone told to define a timer with the frequency I need (50hz):
// TIMER 1 for interrupt frequency 50 Hz:
...
0
votes
1answer
42 views
Weird formatting behavior with sprintf function
I don't know why but since yesterday, my Arduino sketch returns weird data. I've check eaches inputs and the returns values are ok.
But that line:
sprintf(read, "%d;%d;%d;%d;%d;%d;%d;%d\r", x, ...
0
votes
3answers
69 views
How can I concatenate multiple byte Arrays into one Array
I have three byte arrays. I first change their values during runtime and after that I want to combine them into one bigger 4th array.
byte a1[] = { 0x01, 0x00, 0x01 };
byte a2[] = { 0x00, 0x11, 0x01 }...
0
votes
2answers
36 views
Push to 2D array (log) but last value pushed is everywhere
I have this simple that is supposed to keep a log for me with a fixed number of entries. When I add to the log the oldest replaced is by the second oldest etc and the new entry added. Except when I ...
0
votes
0answers
33 views
max7219 chained display showing mirrored text
I'm using a max7219 like this one max7219. When I first tested my circuit, I used an 8x8 display and the code worked just fine. Now, after I modified the code with the one that can be found online at ...
0
votes
1answer
61 views
Help: convert Arduino code to avr-gcc code [closed]
I need to convert Arduino code to avr-gcc code. This is code:
#include <Servo.h>
Servo myservo;
void setup() {
myservo.attach(11);
}
void loop() {
myservo.write(67);
}
I use Arduino ...
0
votes
1answer
18 views
Wait for serial input otherwise start with preconfigured options
I need to input config parameters from serial input. After a period (1 min) with no input I would like the program to start with preconfigured parameters.
Currently in the loop() section I use Serial....
-3
votes
2answers
37 views
Led cube circuit [closed]
I want to make a Led cube of 8*8*8 and I want to control all the led. Can you tell me ho to build the circuit and the cube without multiplexing so that all the led can be controlled? Thank you.
2
votes
1answer
72 views
while(1) loop blocks program to enter interrupt
I want to build a program in C that enables / disables a passive matrix display. But my problem occurs before I can even implement one function of this display.
I have a simple switch connected to ...
1
vote
1answer
62 views
How to send information from a web-site to the arduino?
I currently have an Arduino Mega + an Arduino Ethernet shield, I would like to know if it's possible to send data to the arduino from a web-site hosted on the shield itself. So that when someone press ...
3
votes
1answer
73 views
Making an automated watering system with Arduino
I am trying to make an automated watering system using an Arduino.
Here is my wiring diagram:
And here is my circuit wired up:
Here is the code that I'm using with Arduino. The code seems alright ...
0
votes
1answer
32 views
Printing multiple double qoutes in print statement
I'm trying to print multiple quotes in a Keyboard.print() function but when i try to escape the character with \ at $output =\"$HOME\Misc\nc.zip\"" and the string does not get recognized by the ide. ...
0
votes
2answers
51 views
Timer for how long button is not pressed
I would like to timer for how long a button is not pressed. So actually if(buttonState == LOW 'for two seconds') than execute the code that comes after it. But the problem is while the user is still ...
0
votes
2answers
69 views
Use of struct and sizeof in C for Arduino
I am a newbie in C and I can not understand the point of using a structure in C. Could someone explain to me what is the point of defining a structure in C programming?
For example, this code(written ...
0
votes
1answer
76 views
How to break out of a loop if it is contained in a function
I am trying to figure out how to break out of a loop if it is being called from a function. I have a similar post, here, that I've decided to do something with the Arduino onboard LED, to isolate it ...
1
vote
3answers
64 views
Traffic lights using timer
My traffic light code for the ardunio doesn't run as I was wondering if anyone could point out where my issues lie. The red and green LEDs should be on for 15 seconds and the amber on for 5 seconds.
#...
4
votes
2answers
92 views
How to move my robot in the right direction?
After all there is more question poping up then answers i decide to upload the pdf where is everything writen, like the wire, motor type and what we can and can't use. Here is the link pdf format of ...
1
vote
1answer
61 views
AVR timer overflow interrupt not working
My problem is an interrupt service routine (ISR) that seemingly never executes! Here's some info on my set up: I am flashing an avr attiny85. I have the bare bones of a project set up so far with ...
0
votes
1answer
33 views
Comma between two values in a macro
I am working on a project involving an Aduino and screen.
As i was going through the u8glib (Arduino Monochrome Graphics Library for LCDs and OLEDs), something caught my attention:
#define ...
1
vote
2answers
54 views
Arduino creating delay function
I am trying to make my own delay function. Briefly mydelay function is calling toggled function every secs seconds. The code is not well written, i know (this is the first version). But i am just ...
1
vote
0answers
62 views
troubleshooting - Turn on a single led in a ws2811 ledstrip with an arduino Uno with FastLed
I want to to turn on a single led in a ledstrip running on ws2811 with an Arduino Uno.
The problem is that when I try to turn just one of them on, they all three light up. The strip is a 3-wire ...
0
votes
2answers
54 views
digispark - 2 pin push button to iterate through an hashmap
I'm trying to create a project with my digispark where i can iterate through an hashmap, when i press the push button the digispark writes via digikeyboard the values from an hashmap. Each time i ...
0
votes
5answers
129 views
How to run multiple functions one after another?
I want to fade a red LED up and down, then a green LED up and down, and repeat the whole cycle indefinitely.
I've been trying to run multiple functions one after another. However my current code ...
0
votes
2answers
76 views
Inconsistent response AT command
I'm building a vehicle tracker with Arduino shield with Waveshare SIM 808. I am communicating with the Arduino via AT commands, and came across the following problem: The method "leserial ()" returns ...
1
vote
1answer
31 views
Binary message formatter
I am currently developing an IoT device with arduino and i want to minimise the data payload. First i used json which is not very efficent in fixed messages (the format will always be the same). Then ...
2
votes
2answers
56 views
How to animate a LED Strip via wifi? [closed]
I'm remotely connecting my phone to an arduino MKR1000 via wifi, and sending data via HTTP GET (so to switch on the debug LED, I just need to navigate to http://192.168.1.1/debug/H, for example). Now, ...
-1
votes
1answer
46 views
Keep References Between Objects
I'm trying to recreate a small tween engine so I can interpolate values, leds hue, saturation and brightness in a easy way.
I'm having trouble to reference the value to interpolate into my tween ...
0
votes
1answer
60 views
Using pointers with Arduino
I am learning about pointers.
I was wondering how the memory address is defined in programming. I get different outputs depending on the format I choose for memory address. So I was wondering if it ...
1
vote
2answers
137 views
Most memory efficient way to program
I currently know 3 ways to do a program. Which one of them is the most memory friendly. Note that the example code is simple (blinking a led) and the final code will be VERY VERY complex. Also, the ...
0
votes
1answer
43 views
Get pin input status without using the arduino library
I am not allowed to use the Arduino Library (or any Library) for this program. How would I check the input of a pin?
I found two different functions:
In Arduino.h:
#define bitRead(value, bit) (((...
1
vote
1answer
55 views
How to correctly code a LED STRIP?
I recently bought a 5050 RGB 12V 3A LED strip and I set it all up with my Arduino and run this code (from adafruit website), everything is good:
Example Code
Once you have the strip wired up, it is ...
0
votes
1answer
140 views
From Wiring to pure C
I'm using the Teensy 2.0 (atmega32u4) and decided to switch from Arduino IDE with Wiring to pure C. I think it's much more useful to master programming microcontrollers on that level. Wiring seems to ...
1
vote
0answers
35 views
Arduino code not starting at beginning after poweroff
I created a few Arduino-XBee temperature sensor nodes that send data to another XBee node.js server. I'm running into a few issues trying to write a function to initiate a handshake and receive an ...
0
votes
1answer
35 views
Pass custom element of an array from an inherited class to main sketch
I'm building a base class that creates color patterns using FastLed's CRGB structure. I use the base class as inheritance for another more specific class that modifies a vector of colors (Pixels[]) ...
1
vote
2answers
78 views
AVR (Arduino Uno) Serial.print and Serial.println only printing 1 or 2 chars
I first used the Arduino IDE but now I'm using PlatformIO which is awesome. But I have some big trouble with Serial.print() and Serial.println(). To show this error I have the following example code:
...
-3
votes
2answers
82 views
Errors in code, LM35 temperature logging to web server
trying to experiment with Wemos D1 and LM35. Need to have temperature reading on the ESP IP. Found the following project to be exactly matching my requirements but I am having certain errors in it. ...
0
votes
2answers
91 views
The most effective way to format numbers on Arduino
I made a big search about how to Format Numbers with the Arduino. I want to format unsigned Longs into a String in this format: "23,854,972".
The most of the snippets I found work only with the ...
1
vote
1answer
62 views
max7219 chained display showing text only on the first display
I'm using a max7219 like this one max7219. When I first tested my circuit, I used an 8x8 display and the code worked just fine. Now, after I modified the code and changed the display with the chained ...
2
votes
0answers
42 views
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 ...
1
vote
2answers
2k views
How do I convert a float into char*?
Asked this question on Electrical Engineering Stack Exchange and was directed here:
Pretty self explanatory; how would I go about converting a float into a char*? I have code in which the float '...
1
vote
2answers
696 views
Arduino- how do I convert a float into char*?
Pretty self explanatory; how would I go about converting a float into a char*?
I have code in which the float 'resistance' is constantly being updated. I would like to be able to update the variable '...
1
vote
1answer
74 views
What does 16u and 128u mean?
The below is a snippet of a code for operating SI4455 Rf module with Arduino. I have some doubts which I'd like to seek some help in clearing.
byte numOfBytes = *pSetPropCmd++;
if (numOfBytes &...
0
votes
1answer
45 views
How to convert char[] to int with fail\success control?
this is more like C question, but i failed to google this.
i expect a command parameter in char[], but there may be no argument passed at all, so i need to try to parse this char[] to int and if ...
0
votes
1answer
56 views
Data transfer using SPI
Sorry for my code is long and my English is not good.
I'm working with 8x8x8 LED cube project using Arduino nano. I tried to understand code, but I don't understand how cube[][] data write on pins.
...
0
votes
0answers
48 views
Good guides to learn Arduino preferably with C and without IDE
I have played around with Arduino Uno and browsed through some basic introduction guides. I really like that it has been made easy to start programming via IDE and you get the led blinking in no time. ...
3
votes
1answer
51 views
Informations lost in a string
At first, I sorry if I make some English faults but I'm French.
So, I'm making a connection between a client and an Arduino Uno. I receive all data that I need but when I send a response to my ...
0
votes
0answers
82 views
Response to a client
I am new (and French) so, sorry for my English.
I am developing an Arduino application with an Arduino Uno and an Ethernet Shield 2. I need to receive some data from a client (like, e.g. which ...
