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    a module had six pins labelled as vcc, gnd, rx and tx. what kind of communication interface is available in this module to interface to a microcontroller


    Guys, does anyone know the answer?

    get a module had six pins labelled as vcc, gnd, rx and tx. what kind of communication interface is available in this module to interface to a microcontroller from screen.

    Getting started with nRF24L01+

    Getting started with nRF24L01+

    Manoj May 14, 2016 Arduino, Wireless

    nRF24L01+ 2.4 GHz wireless chip from Nordic Semiconductor is the successor to the popular nRF2401 series of chips. The 24L01+ takes all of the good features of the 2401 and adds a true SPI interface, hardware link layer, multiple pipelines, and more…

    They are transceivers which means that each module can transmit and receive data. You can use these modules with any microcontroller (MCU) .

    Pin Description

    GND – GroundVcc   - Supply Voltage (1.9 V – 3.6 V)CE pin is always an input with respect to the 24L01. It is used to control data transmission

    and reception when in TX and RX modes, respectively.

    CSN stands for chip select not. This is the enable pin for the SPI bus, and it is active low (hence the “not” in the name). You always want to keep this pin high except when you are sending the device an SPI command or getting data on the SPI bus from the chip. When this pin goes low, the 24L01 begins listening on its SPI port for data and processes it accordingly.SCK is the serial clock for the SPI bus. When you configure your SPI bus, SCK should stay low normally (rising edges are active), and the clock samples data in the middle of data bits.MOSI stands for “master out, slave in,” and from both the microcontroller’s and the 24L01’s perspectives, the master is the microcontroller and the slave is the 24L01. This is because the 24L01 never sends data without first being requested by the microcontroller. Essentially, this pin is the side of the bus on which the master (the microcontroller) sends data to the slave (the 24L01). It is also connected to the MOSI pin on your microcontroller’s SPI interface.MISO pin is like the MOSI pin, but backwards. This pin is the side of the bus on which the slave (the 24L01) sends data to the master (the microcontroller).IRQ is the interrupt pin, and is active-low. There are three internal interrupts that can cause this pin to go low when they are active.

    Even though the modem operates in 3.3V level, the six pins namely CE, CSN, MOSI, MISO, SCK and IRQ are 5V tolerant.

    Interfacing With Arduino

    In this tutorial, we demonstrate simple client – server communication between two nRF24L01 modules interfaced with Arduino. The connections between Arduino and RF modem is illustrated below. Wire up one more pair following the same connections.

    Since the modem works in 3.3V level and Arduino in 5V level, it is recommended to use a 5V – 3.3V level converter while interfacing them. But for the sake of simplicity, we have not discussed about the level converter here.

    CE       → Pin 8 CS(N)  → Pin 10 MOSI  → Pin 11 MISO  → Pin 12 SCK    → Pin 13 Vcc     → 3.3v GND   → GND

    Note that CE and CSN pins should be connected to the digital pins as defined in the library.

    On Arduino UNO boards SPI pins are connected with some digital pins. While using modem you must remember that these digital pins won’t be available.

    MOSI is connected to digital pin 11

    MISO is connected to digital pin 12

    SCK is connected to digital pin 13

    SS (not used, but also blocks) is connected to digital pin 10

    The Arduino MEGA 1280 and 2560 have a similar situation.

    MOSI is connected to digital pin 51

    MISO is connected to digital pin 50

    SCK is connected to digital pin 52

    SS is connected to digital pin 53

    On the Arduino DUE, Yun and Leonardo SPI pins are on ICSP connector, and are independent of the digital pins.

    In this project we used RadioHead library. You only need to click on “Download ZIP” button and it’ll start downloading all necessary things.  You can install the library in Arduino IDE using Sketch-> Import library-> Add library. Another way is to extract the zip file to your Arduino home directory: Arduino/libraries on Linux or Documents/ Arduino/libraries in Windows.

    With the library, you will get sample codes for nRF24 in examples > nrf24. We used the client, server examples to establish communication between the modules. Here the client sends some data to the server for which it responds with an acknowledgement

    But when we tried with the codes as they are issued, we had to gaze at the terminal for long time to see some data on it. So we decided to set one module as transmitter and the other as receiver with little editing in the code


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    RH_NRF24 nrf24; void setup() { Serial.begin(9600);

    while (!Serial);                             // Wait for serial port to connect. Needed for Leonardo only

    स्रोत : www.rhydolabz.com

    FTDI USB to TTL serial converter module

    The FTDI USB to TTL serial converter module is an UART (universal asynchronous receiver-transmitter) board used for TTL serial communication. It is a breakout board for the FTDI FT232R chip with an USB interface, can use 3.3 or 5 V DC and has Tx/Rx and other breakout points.


    he FTDI USB to TTL serial converter module is a UART (universal asynchronous receiver-transmitter) board used for TTL serial communication. It is a breakout board for the FTDI FT232R chip with a USB interface, can use 3.3 or 5 V DC and has Tx/Rx and other breakout points.

    This is an ongoing post. Please suggest corrections, explanations, etc. in the comment section at the bottom of this page.

    FTDI USB to TTL serial converter modules are used for general serial applications. It is popularly used for communication to and from microcontroller development boards such as ESP-01s and Arduino micros, which do not have USB interfaces.

    Table of contents

    FTDI USB to TTL serial converter module

    Original FT232R chips are one of the newer chips manufactured by FTDI (Future Technology Devices International). Apart from being a USB to serial UART, it has an integrated EEPROM and optional clock generator output.

    The chip also incorporates FTDIChip-ID functionality (giving each chip a unique identifier for security) and USB termination resistors. Cloned boards (with a cloned chip) will likely exclude the unique ID functionality and does not include an EEPROM, meaning that signals cannot be inverted.

    The internal clock (6MHz, 12MHz, 24MHz and 48MHz) can be brought out of the device and used to drive a microcontroller or external logic.

    The module has a mini-B USB port which is used to connect to a USB port of an interfaced device (e.g. a PC). On the other side, the FTDI USB to TTL serial converter module has breakout pins (Tx, Rx, Vc and GND) that are connected to a microcontroller’s corresponding pins.

    Communication takes place using TTL (transistor-transistor logic). It has a 3.3/5V DC jumper and will supply 500 mA through its Vc pin.

    FTDI USB to TTL serial converter module specifications

    Chip: FT232R (FTDI)

    Pins: 6 pin headers and 18 through-hole connectors. DTR, RX, TX, VCC, CTS, GND and PWR, TEN, SLEEP, CTS, 3.3V, 5V, RXL, TXL, GND x 2, TXD, DTR, RTS, VCC, RXD, R1, RSD, DCD (all marked)

    Working voltage: 5V DC

    Level output: 3.3 – 5 V DC (jumper)

    Interfaces: Serial/UART

    On-board LEDs: power on, Rx, Tx transmission, working status

    Operating current: 500mA

    Module size: 36 x 18 mm

    Pin size: male, 5 x 2.54 mm

    Ports: Micro-B USB

    Breadboard friendly: yes

    FTDI USB to TTL serial converter module pinout

    The FTDI USB to TTL serial converter module pinout. Also, note the 3.3 V / 5V jumper connector for the VCC pin.

    The FTDI USB to TTL serial converter module has six, male, 5 x 2.54 mm header pins and 18 through-hole connectors. The header pins are breadboard friendly and all the pins/connectors are clearly marked.

    The more commonly used pins (RX, TX, VCC and GND) are connected to the corresponding pins of the microcontroller (RX -> TX and TX -> RX).

    The DTR pin is connected to the reset pin of the microcontroller, which will trigger an auto-reset signal after a sketch is uploaded.


    Some devices might need drivers to register the FTDI USB to TTL serial converter module to be able to appear as a COM port. This allows application software to access the module in the same way as it would access a standard COM port.

    Although some operating systems might install the drivers automatically after their first use, others might need these drivers to be installed manually. For more information, visit the official FTDI Virtual COM Port Drivers page.


    To get started with the FTDI USB to TTL serial converter, you might need some of the following accessories.

    Please support us by using these links — they come at no additional cost to you, but we get a little commission each time they are used. These and others are available from Amazon.com and BangGood.

    We have tested most of these products ourselves. Other selection criteria include affordability, quality, availability and average user rating and popularity by other buyers.

    Links will open in a new window.

    (Dead or old links can be reported in the comments section below.)

    Amazon.com BangGood

    Featured product

    Geekcreit FT232RL FTDI USB To TTL Serial Converter Module

    FT232RL FTDI USB to TTL serial converter module with Mini-B USB.

    Available from BangGood

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    स्रोत : behind-the-scenes.net


    Learn about RC522 RFID Reader Writer Module along with its Working, Active Vs. Passive tags, Applications, Pinout, Wiring, Library, Code & Arduino Project


    What is RFID? How It Works? Interface RC522 RFID Module with Arduino

    Gone are the days when people waited in long checkout lines at the grocery store, thanks to RFID technology. With an RFID based walk-through automatic checkout solution, you can fill up your cart and walk right out the door. You no longer need to wait for someone to ring each item in your cart one by one; Now with the help of RFID tags attached to the items, every item in the cart will be detected and ringed almost instantly.

    For most of our RFID based Arduino projects, the RC522 RFID reader/writer module is a great choice. It is low power, low cost, very rugged, easy to interface and extremely popular among hobbyists.

    What is RFID technology and how does it work?

    An RFID or radio frequency identification system consists of two main components, a tag attached to the object to be identified, and a reader that reads the tag.

    A reader consists of a radio frequency module and an antenna that generates a high frequency electromagnetic field. Whereas the tag is usually a passive device (it does not have a battery). It consists of a microchip that stores and processes information, and an antenna for receiving and transmitting a signal.

    When the tag is brought close to the reader, the reader generates an electromagnetic field. This causes electrons to move through the tag’s antenna and subsequently powers the chip.

    The chip then responds by sending its stored information back to the reader in the form of another radio signal. This is called a backscatter. The reader detects and interprets this backscatter and sends the data to a computer or microcontroller.

    Hardware Overview

    The RC522 RFID module based on the MFRC522 IC from NXP is one of the cheapest RFID options you can get online for less than four dollars. It usually comes with an RFID card tag and a key fob tag with 1KB of memory. And the best part is that it can write a tag that means you can store any message in it.

    The RC522 RFID reader module is designed to create a 13.56MHz electromagnetic field and communicate with RFID tags (ISO 14443A standard tags).

    The reader can communicate with a microcontroller over a 4-pin SPI with a maximum data rate of 10 Mbps. It also supports communication over I2C and UART protocols.

    The RC522 RFID module can be programmed to generate an interrupt, allowing the module to alert us when a tag approaches it, instead of constantly asking the module “Is there a card nearby?”.

    The module’s operating voltage ranges from 2.5 to 3.3V, but the good news is that the logic pins are 5-volt tolerant, so we can easily connect it to an Arduino or any 5V logic microcontroller without using a logic level converter.

    Technical Specifications

    Here are the specifications:

    Frequency Range 13.56 MHz ISM Band

    Host Interface SPI / I2C / UART

    Operating Supply Voltage 2.5 V to 3.3 V

    Max. Operating Current 13-26mA

    Min. Current(Power down) 10µA

    Logic Inputs 5V Tolerant

    Read Range 5 cm

    For more details, please refer below datasheet.

    MFRC522 Datasheet

    RC522 RFID Module Pinout

    The RC522 module has a total of 8 pins that connect it to the outside world. The connections are as follows:

    VCC supplies power to the module. This can be anywhere from 2.5 to 3.3 volts. You can connect it to the 3.3V output from your Arduino. But remember that connecting it to the 5V pin will probably destroy your module!

    RST is an input for reset and power-down. When this pin goes low the module enters power-down mode. In which the oscillator is turned off and the input pins are disconnected from the outside world. Whereas the module is reset on the rising edge of the signal.

    GND is the ground pin and needs to be connected to the GND pin on the Arduino.

    IRQ is an interrupt pin that alerts the microcontroller when an RFID tag is in the vicinity.

    MISO / SCL / Tx pin acts as master-in-slave-out when SPI interface is enabled, as serial clock when I2C interface is enabled and as serial data output when the UART interface is enabled.

    MOSI (Master Out Slave In) is the SPI input to the RC522 module.

    SCK (Serial Clock) accepts the clock pulses provided by the SPI bus master i.e. Arduino.

    SS / SDA / Rx pin acts as a signal input when the SPI interface is enabled, as serial data when the I2C interface is enabled and as a serial data input when the UART interface is enabled. This pin is usually marked by encasing the pin in a square so that it can be used as a reference to identify other pins.

    Wiring an RC522 RFID Module to an Arduino

    स्रोत : lastminuteengineers.com

    Do you want to see answer or more ?
    Mohammed 7 day ago

    Guys, does anyone know the answer?

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