All Questions
32 questions
1
vote
1
answer
2k
views
How to convert a String to Hex array
I am trying use a HMI display. If I want to send a data, for example I want to write "TOPWAY" to 0x00000080 address it should like that:
Serial.write(0xaa); // packet head
Serial....
- 297
2
votes
1
answer
162
views
Why are characters with value above 127 "padded" with 1s to be 16 bits long, while ones with values 0-127 aren't?
I am using the Arduino IDE to run and monitor, with an Arduino Nano clone.
This code shows what I mean by the question:
char foo = 127;
char bar = 128;
Serial.println(String(foo, BIN));
Serial.println(...
- 23
1
vote
2
answers
3k
views
strcmp doesn't seem to work
I'm trying to compare a char array that I'm assembling to a string and I'm having trouble comparing the strings.
I'm getting the data for the char array as a set of bytes and I'm compiling it into a ...
- 357
0
votes
2
answers
2k
views
Float array to comma separated string
I have a loop command reading temperature sensor data from 8 thermistors and are storing them as floats into an array. Instead of printing to Serial on each iteration, I would like to create a comma ...
- 243
1
vote
1
answer
74
views
How do you make a Class variable array bigger?
I am making an infrared macro-keyboard, I want to store Unicode for the Keyboard class in an array inside a class I made called Keybindand to allow the user to program as many outputs as they want, I ...
- 27
1
vote
2
answers
490
views
Nothing received from function returning array of strings
My read function returns an array of strings. i.e ssid and password
String* configuration::read() {
String rw_ssid = "";
String rw_pswd = "";
const int keys = 2;
String read_ssid_pswd ...
- 575
0
votes
1
answer
1k
views
Scrolling an I2C text
I want tried to make a programm to display a text on an I2C LCD-Display.
The text should be scrolled for one position every time the function is called.
On the internet I saw a lot of solutions but ...
0
votes
2
answers
57
views
Regarding Strings and assignments
I have this code which works :
String ErrorMsg;
.......
if(!UploadPacketError)
{
ErrorMsg="OK";
}
else
{
ErrorMsg="NOK";
}
String creates a dynamically allocated array which I want to avoid. I ...
- 103
-1
votes
2
answers
2k
views
Reading from SPIFFS - What's the best way to deal with a string (or char) array with undefined length?
I've read that it's best to avoid using String in Arduino so I'm ready to use a char array if it's better.
I'm reading the file names from an SD Card and my goal is to store them in an array and then ...
- 165
1
vote
2
answers
2k
views
How to Sort a String with Number by Ascending
I have trouble figuring out how to sort a String that has a Number in it.
The String im sending looks like 112:AAAA and 111:EEEE, how would I sort it so that the 111 will be the first in an array but ...
- 11
1
vote
0
answers
112
views
Problem: char string not working with SoftwareSerial.h
I am creating a program to display text on an OLED display and then have it sent to a thermal printer.
The issue is my second char string: word_buffer
When I try to use word_buffer for any reason it ...
- 11
1
vote
0
answers
380
views
How to store an array of doubles? As array of doubles, Strings or const char *? Then convert back to use?
This seems like an old, solved problem, but I can't find any simple answers.
I'm reading latitude and longitude data as Strings from a file (about 50 points), but they are really double float numbers.
...
- 111
1
vote
2
answers
327
views
ArduinoJSON: Using a reference to a reference when parsing array of arrays
I started to play around with the ArduinoJson library to parse data I got from one of my APIs (the format of the JSON data I get from my API can be improved for sure, but the software I had to ...
- 205
1
vote
1
answer
107
views
Doubt using character array
I'm trying to make a led sign with a WS2812b ledstrip, using the FastLed library (by the way, this is a great library!), I'm already able to show a text (so far only one, which I leave saved in an ...
- 262
0
votes
1
answer
1k
views
String input to character array
I am in between of project where i am getting string like "hello world" via Bluetooth to arduino I want to list this string into individual character so that I can call any of the character when ...
