All Questions

0
votes
0answers
10 views

How to find the MAC address using NodeMCU when connecting to WiFi?

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 ...
1
vote
2answers
26 views

How to combine strings and text together?

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)....
0
votes
1answer
25 views

Trying to power multiple servos at once using a Arduino Mega

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 ...
3
votes
4answers
4k views

Multiple non-blocking countdown timers?

I'm building a control system for three sump pumps using a single Arduino and a set of relays. I have float sensors for each one, and need the Arduino to trigger the relays when the float sensors are ...
0
votes
1answer
45 views

Problem uploading to board error, but I've selected the port and the board type?

I am having an issue when I try to upload a program to the board. I am working on a Simon Says game, and when I first started uploading, my computer handled it fine. Everything worked properly. ...
1
vote
2answers
50 views

Can Arduino Uno R3 board remove chip on the board

First off, got my Elegoo Uno board as Christmas gift, so this is all new to me.  Here is my problem, I built an motor project and the chip has been programmed. Can I remove the chip from the Uno ...
0
votes
0answers
11 views

Ethernet Shield - Not Working Properly Always

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 ...
0
votes
0answers
18 views

error: 'View' does not name a type

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....
0
votes
0answers
17 views

Nested “switch” statements menu

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. ...
-2
votes
0answers
24 views

How to communicate with Arduino using Bluetooth/WiFi

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 ...
0
votes
0answers
9 views

HC-12 or S14432 for multiple transmitters

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 ...
6
votes
5answers
65k views

Clear existing array when getting new serial command

I'm starting to build my first Arduino project but I'm running into some problems with serial communication. I get serial data from the console and store it in a char array called "data". Then, when ...
0
votes
0answers
13 views

How can I merge my two scripts: Basketball Timer & Basketball Scorer?

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 ...
0
votes
1answer
22 views

Dynamically modifying the call stack using pointers

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 ...
0
votes
3answers
2k views

Motor controller for 24v motor, Arduino Uno

I need a motor controller for a 24v motor and I want to control it using än Arduino Uno. Suggestions? The motor needs to run both directions and is going to draw about 5A
0
votes
0answers
10 views

'inet_addr_to_ipaddr' was not declared in this scope

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 ...
0
votes
0answers
49 views

How to get PWM frequency to ~14KHz?

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 ...
0
votes
1answer
25 views

How do I use a 5v/120v relay that is not mounted on a board [on hold]

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 ...
3
votes
2answers
2k views

Arduino Mega + SIM808 GSM + GPS Module + Program Switch ON without pressing Push Button?

I am new to IOT and tried out integration and a small test code with an Arduino Mega + SIM808 + GSM + GPS Module. It works fine with the SIM808 Library. My requirement is to put it in an enclosure, ...
0
votes
0answers
12 views

ESP-13 WiFi shield - “error: espcomm_upload_mem failed”

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 || ...
0
votes
0answers
19 views

Why is arduino Mega2560 taking so much time to recognise the pin is no longer at HIGH?

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 ...
0
votes
0answers
11 views

Using pulseIn() to read from an RC receiver is giving erratic/no values

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 = &...
1
vote
0answers
75 views

integer corruption

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 ...
0
votes
1answer
48 views

Analog output gives a close range of values

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 ...
1
vote
1answer
69 views

Looking for a waterproof SPI temperature sensor

In my current project I'm using a DS18B20, which seems to be the only temperature sensor to show up when googling for waterproof temperature sensor for an arduino. The sensor itself is fine, however, ...
0
votes
2answers
35 views

Can Serial be safely used in an SPI interrupt routine

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 ...
0
votes
1answer
15 views

Display Wireless Temperature Sensor data to Web page by using Serial communication

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 ...
0
votes
0answers
31 views

Checking Arduino 5/3.3V under load

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 ...
1
vote
1answer
34 views

Does Arduino C++ support dynamic arrays of objects

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 (...
0
votes
0answers
21 views

vscode arduino integration errors

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 ...
-2
votes
0answers
21 views

where can I get “soc/soc.h” [on hold]

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 "...
0
votes
0answers
22 views

Arduino Mega and ADS1256 board

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 <...
0
votes
0answers
14 views

No matching function for call to 'TembooChoreo::TembooChoreo()'? TembooChoreo SendSMSChoreo; Error Help

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 ...
0
votes
1answer
38 views

Failsafe Arduino

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 ...
0
votes
0answers
21 views

How to convert jpeg byte stream into jpeg image and display on 1.8 inch TFT display

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 ...
0
votes
1answer
32 views

Can a push button be used for TFT LCD screens?

I am trying to link my TFT LCD touch screen to a few push buttons. May I enquire why my code is not working? I'm trying to link the screen and the button so I'm trying to make the image display a ...
1
vote
2answers
5k views

Problems with I2C connection on ESP8266 - 12F, which pins should I use?

Previously I had pined the temp/hum sensor HDC1080 with an Arduino using this sketch and everything worked fine. Now I want to run it over an ESP-12F, I uploaded it but it has issues at the time of ...
3
votes
5answers
1k views

Simultanous button reading?

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() { ...
-2
votes
0answers
18 views

Arduino DHT11 sensor not working [on hold]

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?
12
votes
4answers
96k views

How can I declare an array of variable size (Globally)

I'd like to make three arrays of the same length. According to the documentation, Arrays must be defined as int myArray[10]; where 10 can be substituted for a known length (another integer), or filled ...
0
votes
1answer
602 views

Specified folder/zip file does not contain a valid library

I am trying to use this library. But when I try to import the .zip file (of the directory) downloaded from GitHub, Arduino IDE says "Specified folder/zip file does not contain a valid library"
2
votes
3answers
18k views

How to determine Flash size?

I need to determine the flash size of my ESP8266 on my NodeMCU module in order to flash the AT firmware onto the board. Apparently different boards come with differently-sized flash memories. Can ...
0
votes
0answers
19 views

Using TCA9548A to read 30 ADCs

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,...
6
votes
2answers
29k views

Set PWM frequency to 25 kHz

I currently can set four PWM pins to around 31 kHz with the following code: void setup() { TCCR1B = TCCR1B & B11111000 | B00000001; // Set PWM frequency for D9 & D10: pinMode(...
0
votes
1answer
24 views

NRF24 vs commercial RC transmitter [on hold]

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 ...
0
votes
2answers
82 views

Arduino Voice recognition

Is it possible to use only arduino to do voice recognition? or maybe with esp32 no internet. I found speech recognition chip but that's not what i want I got esp32 esp8266 and arduino board. I would ...
0
votes
1answer
37 views

About Wemos D1 WiFi

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 ...
0
votes
1answer
29 views

Running 2 channel 5V relay with nodmcu esp8266 [on hold]

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 ...
1
vote
1answer
400 views

Simple reading and writing on Floppy Disk

I am trying to interface a 3.5" floppy drive (read and write data onto floppy disc). Since I need to write just few bit long number on it (16 is more than enough) I am thinking I could write it track-...
-1
votes
1answer
22 views

Arduino IDE / Specified folder/zip file does not contain a valid library

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 ...

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