All Questions

I am new to using NodeMCU and IOT. I am testing the NodeMCU (ESP8266) so that I can connect with pubnub server. Have taken code from github but there is error saying 'mac was not declared in this ...

I'm working on a school project and using Arduino Uno. The basic working method for the project is as follows: Read temperature from LM-35. Read CO2 level in air using MH-Z14A. Upload data to server ...

I'm trying to combine two strings (strings/int) together with text in below code: int foo = String((char*)payload).indexOf(' '); int message1; int message2; message1 = String((char*)payload)....

The code seems to be good, but I get the mentioned error. Let's have a look at the code: view.h #ifndef _VIEW_H_ #define _VIEW_H_ #include <Arduino.h> #include <ds3231.h> #include "info....

I have a project in arduino, an arcade basketball machine using 4" Single-7-Segment Displays driven by IC 74HC595N. The purpose of my program is to record the score by merging 2 SSDs at the same time ...

I am using ESP32 Ping from this page: https://github.com/pbecchi/ESP32_ping It works fine on ESP32, no compiler error. Because something wrong on my PC, I did fresh install Windows 10 and Arduino ...

I know that menus were discussed perhaps a thousand times here and everywhere. But using a ready solution is not something that I'm looking for because I know I won't learn the concept if I use them. ...

I would like to make a project where an Arduino is able to receive texts from my iPhone and then flash a led when I receive a notification. I never use an Arduino and I am wondering if an Arduino ...

I bought an arduino kit, and it came with, amongst other things, a 5v relay to control 120-220v. The relay is only that, there is only the 5 pin relay, and it's not on a board on which one can ...

I want to build a property monitoring system that can monitor up to 15 different battery powered sensors around the property and report alarms wirelessly back to one main mega about 600’ away (line of ...

I am creating a web server with Arduino and a ESP-13 WiFi shield. The wiring is as following: Arduino UNO || ESP-13 WiFi shield 5V || .5V GND || GND TX || RX RX || ...

I am in my first arduino steps. I have a Mega2560R3 I wrote this code const byte D0 = 22; const byte D1 = 24; const byte D2 = 26; const byte D3 = 28; const byte D4 = 30; const byte D5 = 32; const ...

In a C++ Arduino library, can we modify the call stack from inside a function by intentionally decrementing a pointer to a stack variable so that it's out of range? Like this: void FooBar() { char ...

I'm trying to read values from an RC receiver into an ardruino uno r3 using this code: int input[4] = {0, 0, 0, 0}; int *elevator = &input[0], *aileron = &input[1], *rudder = &...

I have anecdotal experience that using Serial.print inside a slave's SPI interrupt routine (ISR) causes issues with transmission. It also seems that interrupts may be called more than once before the ...

I found this question: Set PWM frequency to 25 kHz It is useful, however, I want to use it to generate ~14KHz? int d = 0; // pwm value void setup() { // Sets Timer1 to Phase Correct ...

Is there a way to use common/cheap components to put the 3.3V and 5V pins on an Arduino under load, in order to measure if they are giving a correct and stable voltage? Can I calculate a certain load ...

I'm just trying to understand how vscode can compile arduino sketch. Now I uploaded some sketch to arduino and it was fine. Now I'm trying to add my own header files to .ino sketch and I got weird ...

My C++ is seriously out-of-date, and I'm working on a project that will be juggling multiple timed actions at the same time, with a menu system to manage the interface and control those timed actions (...

I am trying to follow the instructions for a project given here. What do these parts of the code mean, and how can I obtain the files? #include "esp_err.h" #include "esp_wifi_types.h" #include "...

Recently I have been trying to do a project for my end of year project, it involved making a humanoid arm. I am still a newbie at these things, I usually have my friend do the wiring, but since he ...

I have an ESP32 having a cam and it is transmitting compressed JPEG stream. TTGO T-Journal ESP32 Camera Development Board OV2640 SMA WiFi 3dbi Antenna 0.91 OLED Camera Board I have an ESP32 ...

I try to get a good range of values from VMA309 sound sensor. However, when I connect it properly it gives me a range of values +/-5 like below. The documentation says it should give numbers ...

I've connected my DHT11 sensor to a digital pin and supplied it with 5V DC, and when I print the humidity to the serial monitor, it keeps on showing -999%. What do I do?

I want to read an RFID tag using an Arduino, which controls some relais. This is easy. For me the more complex part is to build it fault-tolerant. So I thought I could use the watchdog. The tricky ...

I use a sensor to measure the temperature. This is returned as float. I feed this float using typecasting (int) to a blink function. This works fine. But the next is step is using this same unchanged ...

Arduino: 1.8.8 (Windows 10), Board: "Arduino/Genuino Uno" C:\Users\user\Documents\Arduino\intruderAlarmTest\intruderAlarmTest.ino: In function 'void loop()': intruderAlarmTest:46:18: error: no ...

Ok, newguy with a little VBA coding experience going to pull hair out soon. It is probably a simple thing I have missed but I would like someone to point out where I went wrong. I modified a sketch ...

I was looking for a suitable RC transmitter with over 6 channels. A friend suggests me that I make one myself using Arduino and the NRF24 2.4GHz radio modules. I would like to follow this ...

I found code for a Teensy board and now I added just digitalwriteFast library to code and changed port to SPI for Arduino Mega. And now I get just one number out: #include <SPI.h> #include <...

Arduino: 1.8.8 (Windows 10), Board: "Arduino/Genuino Uno" Error reading file (E:\arduino\arduino-1.8.8\hardware\arduino\avr**\boards.txt:0**): Invalid line format, should be 'key=value' Error ...

I am working on a very long code that requires multiple functions defined. I want to split the code into two files as main code ("Feeder_Control" in the screenshot) and functions ("connections" in the ...

I am using an Arduino Uno and I want to transmit data from FSi6 to FS-iA6B and read received data in an Arduino. After searching, I found the below link which is iBUStelemetry. iBustelemetry I am ...

I bought the Wemos D1 WiFi and I am wondering how to operate this. So, inside the Arduino IDE, I downloaded ESP8266 boards, I see WeMos D1 mini, WeMos D1 R1, and WeMos mini Pro/Lite. Why in the world ...

I am using Atmega328p with 5V power supply, My Arduino getting hangs [or auto restarts] after some times. I am using libraries: Wire.h CRC32.h EEPROM.h Arduino.h TimerOne.h RtcDS3231.h ...

All the tutorials I can find are for use with Things Network or another Gateway-as-a-Service solution, but my use case requires that the entire network (nodes and gateway) be moveable and usable ...

I'm trying to use Arduino to send IR code through an infrared LED to my TV and haven't found luck so far. My schematic looks similar to the one at https://electronics.stackexchange.com/questions/...

I trying to add library here but it doesn't seem to work https://github.com/esp8266/Arduino This happens "Specified folder/zip file does not contain a valid library" This problem make me no longer ...

I am cry for help & search many articles with no solution.pls anyone guide me. I connect my relay with nodmcu in 2 ways 1st one a) Vcc = 3.3v from nodmcu b) in1 = D4 of nodmcu c) in2 = D5 of nod ...

Apologies for the simple question, I really couldn’t find any help online with this as when I kept searching, the results had lights that had way too much voltage compared to what I need. So I have a ...

My C++ is very out-of-date. (20+ years, before C++ had closures). I'm a senior SW engineer, and I spent several hours yesterday trying to figure this out, but I could not work it out. The background:...

When reading up on how to make a circuit that turns an LED on when a button is held down, I keep finding people saying a pull up or down resistor must be involved, to avoid the flickering state of the ...

Anybody have any experience using AD7849 with Arduino Nano? The 16 bit DAC I mostly see in google searches is AD5662. The only one I could find was AD7849. Any advices before I dive in?

I'm currently working on a project that requires that I simultanously check the state of two buttons. Each button HIGH state is assigned to one if loop. Here's the basic concept: void loop() { ...

I was wondering this, because realized it takes quite time consuming due to all the lines of code I have to write.

I'm trying to connect to an arduino Mega At2560 unit connected via usb serial port in my linux based PC. Using C code, I'm trying to send and receive simple text strings, just I'm able to send and ...

I am reading from wireless temperature sensor with help of gateway receiver connected to Arduino UNO, using this code I need to display the data of the wireless sensor on the webpage. Any ...

http://forum.arduino.cc/index.php?topic=590532.0 What I still lack for the above display would be something like ON / OFF or SLEEPIN / SLEEPOUT. The used controller ILI9341 should be able to do that....

I've been struggeling with this assignment for school for a couple of days. I have finally figured out where the problem lies. I have an oled screen that is supposed to print out the temperature of a ...

I want to read 30 differential ended analog sensors. Using ADS1115 16 bit this is possible, but we end up having only 4 address on I2C, so i chose TCA9548A breakout board with 8 I2C multiplex channels,...