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I have two microcontrollers - NodeMCU (esp8266) and Arduino NANO. I want to transfer data from Arduino to NodeMCU.
I connected the pins rx - rx, tx-tx gnd-gnd, 3v-3v. And wrote Arduino Serial.write(1), and Nodemcu Serial.print(Serial.read()). But for some reason, nothing outputs to the NodeMCU com port
Tx goes to Rx, Rx to Tx. And hook grounds together like you did.
Your NodeMCU code would look like this inside of loop:
if(Serial.available()){
Serial.print(Serial.read());
}
That way it's not transmitting any gibberish when you're not sending anything to it. You will see the tx and rx light flash quickly everytime it sends or receives.
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I have recently bought an OLED SSD1306 Monochrome (White) display. I wanted to connect this display to my Nodemcu ESP32 board, but nothing seems to work. I used the Pinout sheet of my board to connect the display correctly. I checked my wiring multiple times but nothing seems wrong. I thought that the problem might be from my I2C address. I tried the I2C scanner but it doesn't return me any address. I need your help! Since no tutorials exist for the Nodemcu ESP32 connection to the OLED SSD1306 display, I would appreciate any help with the wiring and the code.
PS: I am a rookie so forgive me if I made any newbie mistake!
*I have the Nodemcu version of ESP32 which Not ESP32
the screen did not turn on at all
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I wrote a program to control 5 servos through a web server, The Arduino sketch should display the URL to the webserver that is used to control the servo motors but when I open the serial monitor It does not display anything.
Here is the sketch
I've tried different baud rates but the specified rate for my ESP8226 Node MCU is 9600. Any help is appreciated
You've got to give us more information about the issue. In your setup you print
Serial.print("Use this URL to connect: ");
Serial.print("http://");
Serial.print(WiFi.localIP());
delay(1000);
Is this the section of code you are experiencing a problem with? Do you see any output at all on the Serial monitor?
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I just want to create a system which can scan barcode using barcode scanner(with USB) and send to arduino TX and RX pin. When i google about USB cable, I found USB cable also have TX and RX (D+ and D-). Why I cannot receive data from USB to arduino when I connect direct from TX and RX arduino to TX and RX USB (D+ and D-). I hope someone will tell me why? TQ
USB TX/RX pins follow a totally different electrical specification to that of the UART TX/RX pins of the Arduino.
USB is a differential signal where as the UART of the arduino expects a 5v logic level.
Connecting both together risks damaging both devices.
You can buy USB host "shields" for Arduinos which would allow you to connect this USB device (theoretically)
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I am a software developer with no prior experience in embedded programming. I have to develop a prototype project:(example) to generate Morse Code pulses which are to be output through a solenoid in the form of vibrations. I found that either Arduino Nano or Micro will do this job. Though I have choosen Uno for the project keeping in view later requiremenst will evolve.
I found Leonardo & Uno two close varianst. I selected Uno based on some research I did. Mainly I learned Leonardo is not good choice for beginners due to some of its problems and/or features. Uno also has more help available too being a seasoned variant.
It will be nice if I can have some opinion about it.
As you and Keshav Saharia said, assuming that the capabilities of Uno and Leonardo both meet your needs, the reason to choose the Uno is because it is older, more mature, and better supported. For example, most of the Arduino posts here and on EE.SE are either based on Uno or are compatible with Uno. Likewise, most of the Arduino guides work out-of-the-box with Uno, but not necessarily with Leonardo; Leonardo is always one of those footnotes: If you have Leonardo, you need to do this other thing instead.
Also, if, at some point, you decide to ditch Arduino and use a bare ATmega chip, ATmega328, the MPU in the Uno is the one you are likely to use, and also the one more people are familiar with. Leonardo uses a different AVR chip, the ATmega32u4, which, like the Leonardo, is not quite as popular (widespread?). These are good reasons to choose the Uno, as far as I am concerned.
On the other hand, if you are hoping to keep the prototype board for yourself, you might want to think about the Leonardo, since it is more powerful: more IO, second hardware serial port, etc.
You already asked this question and it has been answered. Your conclusion that the Arduino Nano or Micro won't do the job is wrong. Any version of Arduino will work, as will any other microcontroller (Basic Stamp, Picaxe, etc.). All you need to do to control a solenoid is to turn a digital pin from LOW to HIGH. You WILL need some external circuitry because of solenoid power requirements but the circuitry is trivial.
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I have a stand alone atmega328 and an Arduino Nano. I want the Nano to digital read one digital outputs from the stand alone atmega328. Do I need a Resistor? If yes, how many ohms?
if your Arduino Nano and your Atmega328 are powered by the same power supply, you will be able to connect 328's output to the nano's input without any kind of trouble (no resistor, just the wire or trace). If they're not powered by the same power supply you should connect their grounds together.
Hope it helps.
No, you don't need any. Both ATmega328 and Arduino Nano have internal pull-up resistors, it's the matter of the GPIO configuration.
Some links:
Arduino digital pins
ATmega328 datasheet (check paragraph 13.2)
NB: As mamodom pointed out, you need to share ground between two of your boards.