All Questions

-2
votes
1answer
59 views

How to communicate between Arduino and another Arduino [closed]

I would like to establish a serial communication between two Arduino and I wrote the following test code. Receiver Arduino sketch: void setup() { Serial.begin(4800,SERIAL_8E1); } void loop() { ...
0
votes
0answers
19 views

How can I fix a “MbedTLS error -17040” issue with my arduino code on ESP-32?

Despite several days of searching, I can't find any resources to check the MbedTLS error code "-17040". All of the error codes descriptions available are referencing only hex format errors (which the ...
0
votes
2answers
33 views

Calculate the Li-Po Battery Level in ESP-Wroom-02

I am very new to micro controller and circuits. I am not at all with this field. But trying to create a home project where I have a device image attached below. This is 18650 Lipo battery powered ...
0
votes
1answer
41 views

(Arduino Uno) Is my code for a follow the sun project valid? We want the motor to stop when both photoresistors have the same amount of light

int RlightPin=0; //pin for right Photoresistor int LlightPin=1; //pin for left Photoresistor int TranslateAnalogR=0; int TranslateAnalogL= 1; #include <Servo.h> //Servo library. int pos=90; ...
0
votes
0answers
30 views

Running 5v and 12v strips together?

I want to run 5v and 12v strips and halos together, i read that with the 12v strips, give 12v to the strip but the data is always 5 volts, and tie the ground to the ground of the 5v controller? I use ...
0
votes
0answers
38 views

LED turning on late

I am using an Arduino nano and an ESP8266. I have burnt an Arduino, but when I send a request to the Arduino LED, it takes some time to turn ON. Here is my code: #include <SoftwareSerial.h> ...
0
votes
0answers
39 views

How connect to iot device without predefined wifi and password

I bought a Sonoff switch to understand how it connect to my wifi without predefined ssid and pass. But I couldn't understand its logic. When I want to use ESP8266 module with Arduino, how my phone ...
1
vote
2answers
30 views

Leonardo - always on power, status remains between computer reboots?

I'm looking for two answer here. Is it possible to power a Leonardo to be always on, separate from the power from the USB host - I've tried with a full size Leonardo and a power adapter but for some ...
0
votes
1answer
19 views

Debugging a Nordic MCU (feather NRF52) using Segger J-Link

I have an Afafruit NRF52 board with SD 132 and 5.1 dual fw bootloader. I implemented RTT logging and controlling (input) and the code is compiled using arduinoBuilder with RTT and debug level 3. The ...
0
votes
2answers
36 views

Analog vs Digital Accelerometers - pro's and con's? [closed]

For my project i need to measure accelerations up to 16g. My options are either digital accelerometers such as the MPU6050 or MPU9250 or an analog accelerometer such as the ADXL326. What are any ...
0
votes
1answer
30 views

strcat char concatenation trouble

Still don't understand about char concatenation. void setup() { testCounter(3); } void loop() { // put your main code here, to run repeatedly: } char testCounter(int countx){ char a[10]; ...
1
vote
2answers
55 views

Is it okay to short IN and GND pins of relay module with controller ground? [closed]

I have this relay module that is attached to an ESP8266 (Wemos D1 Mini). Currently, I operate the relay by shorting the IN and GND pins to ground (relay module uses low state to energize) with a ...
-1
votes
1answer
46 views

The code is working fine with Arduino Uno but not with NodeMCU

I uploaded program MPU6050_DMP6_Multiple.ino (https://github.com/eadf/MPU6050_DMP6_Multiple/blob/master/MPU6050_DMP6_Multiple.ino) to Arduino Uno and it works fine. When I upload the very same code to ...
0
votes
0answers
20 views

Making a ATMega328P-PU and computer communicate but not by standard serial communication

So i have been trying to make a ATMega328P-PU using the Arduino bootloader and a computer communicate the same way brands like Logitech and Razer makes their mouse's and keyboard's communicate with ...
0
votes
0answers
28 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. ...
0
votes
1answer
37 views

Newbie question: Set servo at certain degrees when something happens

I am trying to set my servo at f.e. 90 degrees when the friendlyValue of the soil sensor is < 50%. The servo isn't moving at all, is it because the code is running too fast and the servo doesn't ...
0
votes
0answers
14 views

Parsing multiple jsonObjects with Arduinojson and return a list of values

I am building a table tennis score board which parses json objects with ID and names of players to let the players pick their name inside a menu and later on submit the scores to my server. But I am ...
2
votes
1answer
27 views

How to upload Arduino C code to mBot?

I am trying to program mBot using Arduino IDE. I am connected to the mBot using USB on COM7, I am able to upload a code created in mBlock 3.4.11 fine, using "Arduino Mode" as the editing mode. I would ...
0
votes
1answer
29 views

SSD1306 allocation failed when adding a constant

I am trying to get this code working: #include <Button.h> #include <SPI.h> #include <Wire.h> #include <Adafruit_GFX.h> #include <Adafruit_SSD1306.h> #include <RTClib....
0
votes
1answer
44 views

Detect power interruption on NodeMCU

Im using a 5v 1A power supply and connected to VIN pin on the NodeMCU. I also use 18650 battery to keep NodeMCU running in case the power supply shuts off due to power interruption. I'm planning to ...
0
votes
1answer
47 views

Does UNO and Nano have the same pins?

Do Arduino Nano Atmega328p have the same pins as Arduino/Gizduino Uno Atmega328p?
0
votes
2answers
55 views

Reading Multiple Analog Input Pins

I am having a bit of trouble trying to read multiple Analog Input Pins (A0 and A3, in this instance). I am using a Pololu A-Star 32U4 LV Robot Controller (https://www.pololu.com/product/3116), and am ...
0
votes
0answers
25 views

Have terminal bash script act as virtual “button” for Leonardo?

I've searched quite a lot for this and tried to piece bits of code together but with no luck so far. All i'm looking to do is have a command I can run in terminal/bash script on the Mac trigger some ...
-1
votes
1answer
35 views

Divide two integers resulting into a float

Suppose I want to divide two integer variables and put the result into a float. In order to prevent integer division do I have to program like this: int i = 6312; int j = 258; float f; ...
0
votes
2answers
27 views

ESP8266 Switching firmware on the fly

Can you help me out to understand if this is possible with ESP8266 / 32 ? I have a main binary that i upload to the chip, let's call it A - that's done from arduino. A starts to work, but ...
0
votes
1answer
25 views

Cannot get esp8266 - 12 wifi module to always read analogRead incoming voltage accurately

So I have and arduino uno that is firing an output on pin 8. This code is not in this file just to be clear. From there Im taking that output and using it to fire pin 0 on the wifi module. Im using ...
0
votes
0answers
25 views

ESP8266 WiFi.softAPgetStationNum() can only increase?

So using the ESP8266 in STA_AP mode, the amount of Stations connected to the AP can be figured out by running a WiFi.softAPgetStationNum() line. But let's say Alpha is my AP. And Bertha is a Client ...
0
votes
1answer
49 views

Newbe needing help with fixed string length

im trying to build a bit of test equipment that will talk to some software and it needs to send a fix string. when the voltage changes the string length does as well. i need to cap the results to 4 in ...
0
votes
2answers
41 views

Calculating Bluetooth Signal Strength using HC-05 modules [closed]

I would like to have two HC-05 Bluetooth modules attached to my Arduino MEGA, both calculating the Bluetooth signal strength, emitted from my phone, to determine whether the phone is located in front ...
0
votes
1answer
55 views

74HC595 shift register not working

I got my Arduino kit a few days ago and I've been going through some of the tutorials. I got to the 8 LEDs with a shift register tutorial, where I got stuck. Nothing would light up after I plugged ...
0
votes
1answer
14 views

Arduino Nano Midi to cv convertor interesting issue

I created the circuit in this schematic on protoboard, and the code, https://github.com/elkayem/midi2cv I use a dual opamp and a single dac, because i only need note and velocity. The opto i use is, ...
0
votes
1answer
20 views

Multiple definition error when linking firmware.elf

I just can't wrap my head around on how to properly work with multiple files. My code has been getting quite big so I decided to split all the classes into one file each. So I'm left with 6 files: ...
0
votes
0answers
27 views

Garbage output/ not running at start up nodemcu

I have a nodemcu acting as a thermostat home office. The wall heating element is controlled with a solid state relay on D2. If i have it connected, I cannot program the board from the arduino ide. I ...
0
votes
1answer
31 views

Cannot get pins on esp 8266 adafruit wifi module to read HIGH on pin 15

I have an esp8266 and I cannot get the value to read HIGH when 3.3v is applied to directly to pin by hand. I have an Arduino Uno powering the esp8266. It connects to the WiFi like it should, and now ...
-1
votes
1answer
26 views

Problems with Arduino + IR + Raw code low memory

im having a problem with my new project with arduino + ir emitter + big raw codes. I've tryed this way: https://gist.github.com/jjmjr/41ed083c8229d0218c962641c5af27b0 As you can see each of my raw ...
0
votes
1answer
42 views

Arduino Uno: avrdude: stk500_recv(): programmer is not responding

I have an original Arduino Uno board purchased directly from the official arduino website. I have used it successfully with IDE v1.8.5 on my Windows 10 laptop for various projects in the last 6 months....
0
votes
2answers
55 views

How is this simple transistor circuit suppose to work? [closed]

I've tried to replicate this circuit today. My motor is a computerfan, they apperntly don't need a flyback diode since there are no brushes. I used a 12V power source for my arduino and hooked it up ...
0
votes
0answers
26 views

NodeMCU with digital sound sensor - Can't find examples or good documentation

I'm very new to this world, and trying to hack one of my first projects have proven hard without solid documentation or examples to copy like I usually do. I've got a https://www.gearbest.com/...
0
votes
0answers
29 views

Packet Loss From Cheapest USB Hardware [closed]

I'm considering making a cheap USB slave device with the ATtiny85 and curious about the inefficiencies I'm accepting. I know that it uses "low-speed USB 1.1" with only 1.5 Mb/s transmission (and no ...
0
votes
0answers
26 views

What would cause one Arduino to be recognized but not another?

I have two Arduinos, A cheap china-knockoff and an original one. I have had no problem with either of them before. But when I moved from connecting the original with a USB A-hub to running it over USB-...
0
votes
0answers
29 views

SG90 not responding with Arduino Uno

I bought an SG90 servo motor, seller demonstrated by direct supply check, it works there but with Arduino servo sweep check it does not respond: no error during compiling and uploading, but it does ...
0
votes
1answer
31 views

MQTT - Can lastwill be sent to multiple topics?

I'm using an ESP8266 as an IOT device, with MQTT to send status messages. Each device have its own availability topic, to state its online or offline state ( needed for Home Assistant indication on ...
0
votes
2answers
37 views

ESP8266 Supply Voltage dropping below 3.3V

I am trying to power an ESP8266 with a 3.3V regulator (this one, can supply ~ 1A). I've been struggling for days to get the ESP to work – it will occasionally boot, occasionally connect, but then not ...
0
votes
1answer
29 views

Digispark Attiny85 ultrasonic sensor input problem

I was trying to use ultrasonic with digispark Attiny85 board and used separate pins for trigger and echo, and used MM5451 led controller as a display, I uploaded the code successfully the problem is ...
0
votes
1answer
20 views

USB Communication between Arduino Nano and UHF Reader module

I am working on a project that requires a UHF reader development kit that can communicate using either RS232 or by USB. Via USB and a Serial terminal, I have been able to send commands to the reader ...
0
votes
0answers
37 views

Arduino is detected by the software, but uploading is impossible [duplicate]

I'm using a Geekcreit UNO arduino clone which worked fine for a long time and now suddenly, it stopped working. The builtin LED and the power LED are on, all pins provide 5V and wenn I try to upload a ...
0
votes
1answer
27 views

How to check whether my arduino-mega ADC is sampling correctly?

I have a code which samples the given input signals with sampling rate 256hz. I plotted the graph of FFT and was able to see the peaks at the expected frequencies.But I would like to know whether my ...
1
vote
1answer
33 views

Arduino based fully controlled aquaculture

I am doing a project on aquaculture,so I am using temperature sensor, water level sensor, dissolved oxygen sensor, pH sensor and also 4 motor's and water heater is it possible for a single Arduino to ...
0
votes
1answer
26 views

Why my LCD does not work with this if statement?

#include <LiquidCrystal.h> LiquidCrystal lcd(1, 2, 4, 5, 6, 7); int greenLedPin = 12; int blueLedPin = 11; int redLedPin = 8; int yellowLEdPin = 9; int lightSensorPin = A0; int analogValue = 0;...
0
votes
3answers
53 views

How to connect multiple I2C devices?

I am trying connecting I2C OLED SSD1306 and I2C INA219 on ESP32 but without success. First try: #include <WiFi.h> #include <Wire.h> #include <Adafruit_GFX.h> #include <...

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