Questions tagged [cpp]
The cpp tag has no usage guidance.
22
questions
0
votes
1
answer
403
views
How to get the scan duration below 1sec with Arduino BLE?
I want to scan continuously for other Bluetooth devices with my ESP32 using BLE. The scan method only accepts integers larger than 0, such as scan->start(1, false). However I want the results to be ...
- 109
5
votes
1
answer
668
views
Delay() and millis() functions don't work in cpp external files
I'm currently facing an issue using delay() and millis() functions in an external cpp file.
The issue is that when I used delay() in my main program (meaning .ino file) it works well but when I call ...
- 53
1
vote
2
answers
372
views
Error compiling ESP32 Wrover Module in Linux Virtual Machine
SO i have been getting this error window when i compile a simple code to run different LED lights on the ESP32-S2-SOLA (Wrovere) module
Code:
int LED_BUILTIN = 2;
void setup() {
pinMode (...
- 21
0
votes
1
answer
56
views
CPP Function param use function with multi params [closed]
I want to specify a function with parameters for a function parameter, but it doesn't come together.
////////////////////////////////////////////////////////////////////////
// Example funch...
void ...
- 11
1
vote
4
answers
166
views
Is there anything wrong with this code
Hi I'm pretty new to cpp.
Could someone review my code and explain any pitfalls or problems?
Below is the code and an example to read from a flow meter with a hall sensor.
Thanks in advance.
Greg
/...
- 23
-1
votes
2
answers
622
views
How to convert an int to const int in Arduino?
For a specific project, I need to convert an int to a const int variable type.
int i = 10;
boolean ShiftRegister[i] //Throws error
const int i = 10;
boolean ShiftRegister[i]// Works Fine
as i am ...
-1
votes
2
answers
185
views
How can I execute a string in my Arduino Uno board?
I was making a project with Arduino Uno ,
It's working is like this it connects to a key pad and a 7segment display ,and when you press a run button connected to Arduino it should run the code written....
0
votes
1
answer
133
views
Can't change pins in AM2320 code, types mismatch
I took a simple A2320 temperature sensor and connected it not to A4/A5, but to A1/A0 pins. SDA => A1, SCL => A0. (In C code they are number 15 and 14). But I can't call the library to take ...
user70125
2
votes
1
answer
247
views
How to use PWM with DRV8870?
I'm using Arduino nano and I'm struggling working with the DRV8870 IC on PWM mode.
When I use analogWrite(_pin, duty_cycle); the motor makes weird noises.
I thought it's because of the PWM frequency ...
0
votes
1
answer
392
views
String array length in function
I know this question has been asked a thousand times, but I can't find a solution for my case.
I what to get the length of a string array in a given function. This is for an arduino board.
#define LEN(...
- 145
1
vote
2
answers
364
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
57
views
what is causing my esp8266 setup function to reinitialise?
Here is code I have written:
#include <stdio.h>
#include <ESP8266WebServer.h>
#define MAX_WIFI_INIT_RETRY 50
#define WIFI_RETRY_DELAY 500
const char* wifi_ssid = "ssid";
const char* ...
- 575
0
votes
1
answer
2k
views
Getting error invalid conversion from 'const char*' to 'const uint8_t*
I have written this sketch, and I am trying to populate the array of wifi hotspots to set the value in html select using javascript dynamically.
#include <Arduino.h>
#include <Hash.h>
#...
- 575
0
votes
1
answer
89
views
trying to make wemos d1 code modular causes collect2: error: ld returned 1 exit status exit status 1
#include "connection.h"
void setup() {
Serial.begin(115200);
Funcs::Connect conn;
conn.connectWifi();
}
void loop() {
}
then connection.h file:
// connection.h
namespace Funcs
{
class ...
- 575
-1
votes
1
answer
92
views
How to respond dynamically by using File Containing Templates?
We are developing a Web Console and REST API for the NodeMCU V3 ESP8266, using ESPAsyncWebServer. We are facing some difficulties to serve dynamic pages using File Containing Templates! We're unable ...
- 99
1
vote
1
answer
64
views
Update class attribute with attachInterrupt
I want to refactor this code
/*
YF‐ S201 Water Flow Sensor
Water Flow Sensor output processed to read in litres/hour
Adaptation Courtesy: www.hobbytronics.co.uk
*/
volatile int flow_frequency; // ...
- 11
1
vote
1
answer
784
views
Using SoftwareSerial.h in .cpp file
I am trying to modularize the different components in my arduino build by using objects, but am having trouble with the one controlling a wireless transceiver, which uses SoftwareSerial.h
I believe I ...
- 181
0
votes
2
answers
941
views
WifiClient and aREST on esp32 - loop until new instructions recieved?
I've created a simple sketch for an esp32 that hosts a REST API that can be accessed via HTTP. Based on the instructions received from the client, the esp32 controls some neopixels with some various ...
- 19
1
vote
3
answers
77
views
Guideline in library creation
According to this example, creation of an Arduino library is quite understandable.
But a few things I would like ask (mostly regarding to what to be defined where) when a library is not that simple:
...
- 965
1
vote
1
answer
5k
views
getting error 'Serial' was not declared in this scope
I am adding Dust Sensor to my particle photon project at home,
I got this GitHub project that I want to test before implementing a final code.
I am not an expert in cpp, I wanted to modularise the ...
- 575
0
votes
2
answers
3k
views
How to store an RFID tag number in a string
I want to send RFID tag number to PHP page. So far I have sent a fixed string to php and it worked, now I am not getting data in string when i scan rfid tag. I want to store every RFID tag number in a ...
0
votes
1
answer
147
views
Changing outputs infinitely for no reason
Im a student and working on a arduino project for IoT competition and me and my team have built a house and I made this code below.
For some reason when I upload it to my Arduino MKR1000 it constantly ...
- 103