In this tutorial we will learn How to interface Arduino UNO with RC522 RF ID Reader using Arduino library for MFRC522 and other RFID RC522 based modules.
This library read and write different types of Radio-Frequency IDentification (RFID) cards on your Arduino or NodeMCU using a RC522 based reader connected via the Serial Peripheral Interface (SPI) interface. Before we move to actual code lets know more about RF ID.
In this tutorial we will learn How to interface NodeMCU with RC522 RF ID Reader using Arduino library for MFRC522 and other RFID RC522 based modules.
This library read and write different types of Radio-Frequency IDentification (RFID) cards on your Arduino or NodeMCU using a RC522 based reader connected via the Serial Peripheral Interface (SPI) interface. Before we move to actual code lets know more about RF ID.
In this tutorial we upload a text file and read it in serial monitor.
ESP8266FS is a tool which integrates into the Arduino IDE. It adds a menu item to Tools menu for uploading the contents of sketch data directory into ESP8266 flash file system.
Download the tool: https://github.com/esp8266/arduino-esp8266fs-plugin/releases/download/0.1.3/ESP8266FS-0.1.3.zip.
In above process we uploaded notes.txt file in ESP flash. In this program we read it and display its contents in serial monitor. Uploading of sketch will not affect sketch data. i.e. uploaded notes.txt file.
/*
* ESP8266 Communication and Protocols
* SPIFFS Direct File Upload Example
* -Manoj R. Thkuar
*/
#include <ESP8266WiFi.h>
#include <FS.h> //Include File System Headers
const char* file = "/notes.txt"; //Enter your file name
void setup() {
delay(1000);
Serial.begin(115200);
Serial.println();
//Initialize File System
SPIFFS.begin();
Serial.println("File System Initialized");
File dataFile = SPIFFS.open(file, "r"); //Open File for reading
Serial.println("Reading Data from File:");
//Data from file
for(int i=0;i<dataFile.size();i++) //Read upto complete file size
{
Serial.print((char)dataFile.read()); //Read file
}
dataFile.close();
}
void loop() {
}
In serial monitor you will get File contents, you can upload images, html and javascript files. examples can be found here
Question: Getting permission “error: cannot access /dev/ttyUSB0”
Answer: Just open terminal (Ctrl+Alt+T) and type this command and enter root password
$ sudo usermod -a -G dialout ${USER}
On Linux (Ubuntu), Arduino IDE will not be able to upload sketches (or communicate with the board at all) if you don’t change permissions on /dev/ttyUSB0 appropriately. Same as with the NodeMCU ESPlorer IDE, etc. Actually, this very problem comes up whenever you want to access a (virtual) Serial COM port on Linux.
It might happen that when you upload a sketch – after you have selected your board and serial port -, you get an error Error opening serial port … If you get this error, you need to set serial port permission.
Open Terminal and type:
$ ls -l /dev/ttyUSB*
you will get something like:
crw-rw---- 1 root dialout 188, 0 5 apr 23.01 ttyUSB0
The “0” at the end of USB might be a different number, or multiple entries might be returned. The data we need is “dialout” (is the group owner of the file).
Now we just need to add our user to the group:
$ sudo usermod -a -G dialout ${USER}
NOTE: where USER is NOT your linux user name keep as it is.
In some cases, You will need to log out and log in again for this change to take effect.
In this tutorial, we’ll learn how to program your NodeMCU or ESP8266 using an Arduino IDE. NodeMCU board is not available by default.
The NodeMCU ESP8266 is a low-cost WiFi module built by Espressif Systems. Its popularity has been growing among the hardware community thanks to its nice features and stability, to the point that it can be easily programmed using your Arduino IDE.
Note: Sometimes pakage_esp8266com_index.json link is down due to heavy download try again after few hours.
