How to Place an Order
Store Pick Up
Request for Quotation/ International Sourcing
Order Status
Reference: RBD-1354
Length: 8 inches/20 CM (Long) Material: Copper Plated Pin Spacing: 2.54mm.
Reference: RBD-0351
Contactless transmission of data and supply energy (no battery needed) Operating distance: Up to 100mm (depending on antenna geometry) RoboticsBD Operating frequency: 13.56MHz Data transfer: 106 kbit/s Data integrity: 16 Bit CRC, parity, bit coding bit counting Anticollision Typical ticketing transaction: <100 ms ( including backup management)...
Reference: 0245
Choose your desire Resistor value from below:
Reference: 0031
3 Types Available (Please select from option) 1. Male to Male 2. Male to Female 3. Female-Female
Reference: RBD-0768
Size: 5mm Color: RED Head Shape: Round Lens Appearance: Transparent
Reference: 1353
Length: 12.5 inches/30 CM (Long) Material: Copper Plated Pin Spacing: 2.54mm.
Reference: RBD-0761
Breadboard friendly Mounting Style: Through Hole Mounting Direction: Vertical
Module can be used to expand the digital I/O of an MCU using the I2C bus.
Store Pickup Available!
Free Ship Over 5000 BDT
Quality Product
No Warranty
No Replacement
The PCF8574 module can be used to expand the digital I/O of an MCU using the I2C bus.
A common requirement when working with MCUs is the need to add more digital I/O than the device supports natively. The PCF8574 is one of the more popular methods of adding lines as it uses the I2C bus that requires only 2 lines on the MCU. It provides 8 additional digital I/O lines which are easily expandable up to 64.
The module has an easy to use I2C interface that can be configured to use any one of eight different I2C addresses if you want to use multiple modules in the same system or if you run into an address conflict with another device.
The base I2C address of the modules is 0x20.
There are three address jumps (A0-A2) the determines which I2C address to use. As shipped, these jumpers are all set to the ‘-‘ side which is ground or LOW as shown in the picture. The ‘+’ side is Vcc or HIGH.
This puts the module at the base address of 0x20. The jumpers can be moved in a binary fashion to increase the address, so the address can range from 0x20 to 0x27 as shown in the table below.
If you daisy-chain the modules, you will need to set a different address for each of the modules.
| Address (Hex) | A2 | A1 | A0 |
| 0x20 | LOW | LOW | LOW |
| 0x21 | LOW | LOW | HIGH |
| 0x22 | LOW | HIGH | LOW |
| 0x23 | LOW | HIGH | HIGH |
| 0x24 | HIGH | LOW | LOW |
| 0x25 | HIGH | LOW | HIGH |
| 0x26 | HIGH | HIGH | LOW |
| 0x27 | HIGH | HIGH | HIGH |
You may run into devices with the PCF8574A part installed. If that happens, don’t panic. These just use a different starting I2C address of 0x38. This part is offered by the mfr so that if both A and non-A parts are used together in a system, the number of modules can be increased up to a maximum of 16 providing at total of 128 digital lines. The ‘T‘ marking on the devices just denote that it is a surface mount device.
If there is ever a doubt about the I2C address of this or any device, just hook it up to the I2C bus and apply power and ground and then run the I2C scanner software.
The I/O is defined as quasi-bidirectional. A quasi-bidirectional I/O is either an input or output port without using a direction control register. When set as inputs, the pins act as normal inputs do. When set as outputs, the PCF8574 device drives the outputs LOW with up to 25mA sink capability but when driving the outputs HIGH, they are just pulled up high with a weak internal pull-up. That enables an external device to overpower the pin and drive it LOW.
The device powers up with the 8 data lines all set as inputs.
When using the pins as inputs, the pins are set to HIGH by the MCU, which turns on a weak 100 uA internal pull-up to Vcc. They will read as HIGH if there is no input or if the pin is being driven HIGH by an external signal but can be driven LOW by an external signal that can easily override the weak pull-up.
If used as outputs, they can be driven LOW by the MCU by writing a LOW to that pin. A strong pull-down is turned on and stays on to keep the pin pulled LOW. If the pin is driven HIGH by the MCU, a strong pull-up is turned on for a short time to quickly pull the pin HIGH and then the weak 100uA pull-up is turned back on to keep the pin HIGH.
If the pins are set to be outputs and are driven LOW, it is important that an external signal does not also try to drive it HIGH or excessive current may flow and damage the part.
Whenever the internal register is read, the value returned depends on the actual voltage or status of the pin.
The I/O ports are entirely independent of each other, but they are controlled by the same read or write data byte.
The interrupt open drain output pin is active LOW. It is normally pulled HIGH using a pull-up resistor and is driven low by the PCF8574 when any of the inputs change state. This signals the MCU to poll the part to see what is going on. If connecting this pin, enable the internal pull-up resistor on the MCU or add an external pull-up of 10K or so.
If using interrupts with multiple modules, since they are open drain they can be tied together if a single interrupt back to the MCU is desired.
The connections to the module are straight forward.
1 x 4 Header (Male & Female)
1 x 9 Header
These modules are useful for expanding digital I/O.
One thing to keep in mind is that since the device has strong drive (25mA) when sinking current, but low drive (300uA) when sourcing current, it is best to drive LEDs and similar devices that require higher current by tying their anode to Vcc and pulling their cathode LOW with the PCF8574. A current limiting resistor is generally required.
The example program below sets up all 8 lines as inputs and writes a HIGH to them to enable the weak internal pullups of the PCF8574, so these pins will read HIGH unless something drives them low.
Pushbuttons with one side grounded can be connected to these inputs. The MCU which then scans the PCF8574 inputs and prints out any button found to be pressed.
The example here uses the xreef/pcf8574 library that can be downloaded from GitHub: https://github.com/xreef/PCF8574_library
/* This example for the PCF8574 takes pushbutton inputs on pins 0-7 and sends the number of the button pressed to the Serial Monitor window. Pins are normally HIGH and pulled LOW when button is pressed. Uses the xreef/PCF8574.h library */ #include "Arduino.h" #include "PCF8574.h" PCF8574 pcf8574(0x20); // Set (I2C address) //=============================================================================== // Initialization //=============================================================================== void setup() { Serial.begin(9600); for(int i=0;i<8;i++) { pcf8574.pinMode(i, INPUT); // Set all pins as inputs pcf8574.digitalWrite(i,HIGH); // Enable weak pull-ups to pull pins HIGH } pcf8574.begin(); delay(500); // Give the pcf8574 a little time to initialize } //=============================================================================== // Main //=============================================================================== void loop() { // just loop scanning the keys if (pcf8574.digitalRead(P0)==LOW) {Serial.println("KEY 0");} if (pcf8574.digitalRead(P1)==LOW) {Serial.println("KEY 1");} if (pcf8574.digitalRead(P2)==LOW) {Serial.println("KEY 2");} if (pcf8574.digitalRead(P3)==LOW) {Serial.println("KEY 3");} if (pcf8574.digitalRead(P4)==LOW) {Serial.println("KEY 4");} if (pcf8574.digitalRead(P5)==LOW) {Serial.println("KEY 5");} if (pcf8574.digitalRead(P6)==LOW) {Serial.println("KEY 6");} if (pcf8574.digitalRead(P7)==LOW) {Serial.println("KEY 7");} delay(250); }
The latest price of PCF8574 I2C I/O Expansion Module in Bangladesh is BDT 160 You can buy the PCF8574 I2C I/O Expansion Module at best price from our RoboticsBD or visit RoboticsBD Office.
|
Please note that the product information provided on our website may not be entirely accurate as it is collected from various sources on the web. While we strive to provide the most up-to-date information possible, we cannot guarantee its accuracy. We recommend that you always read the product labels, warnings, and directions before using any product. |
|
Product Images are shown for illustrative purposes only and may differ from the actual product. |
Reference: RBD-1021
Operating voltage: 2.5V-5.5V, recommended 5V Speaker Load: 2-8 Ohms Input and Output Connectors: Pins on 0.2" centers Size: 24 x 23 x 105 mm (L x W x H) Net weight: 3g
Reference: RBD-1862
44mm diameter 30 LED Dimmable 50-degree viewing angle
Reference: RBD-0439
Bluetooth Protocol: Bluetooth Specification V4.0 BLE USB Protocol: USB V2.0 Operating Frequency: 2.4GHz ISM band Modulation Mode: GFSK (Gaussian Frequency Shift Keying) Transmitting Power: ≤4dBm Sensitivity: ≤-84dBm at 0.1% BER It’s easy to use and completely encapsulated. You can set it as slave or master. You can use AT command set the baud rate....
Reference: RBD-3166
The GY-SI5351 Clock Signal Generator Module is a versatile and precise clock generation device, capable of producing multiple independent frequencies with minimal error. Controlled via I2C, this module is perfect for applications requiring precise frequency synthesis for audio, video, communication, and general electronic projects. With three independent...
Reference: RBD-2676
Suitable for use with a wide range of stepper motors and drivers. Can be integrated into a simple control platform with a stepper motor and DC power supply. Offers three selectable low-frequency signal options: high (5.4k-160kHz), middle (540-16.6kHz), and low (80-2.4kHz), adjustable via jumper settings. Capable of producing both pulse and PWM signals,...
Reference: RBD-2489
Wiznet Compact W5500 Network Module - 10/100 Base T WIZ850io is a compact size network module that includes a W5500 (TCP/IP hardwired chip and PHY embedded), a transformer and RJ45. It can be used as a component and no effort is required to interface W5500 and Transformer. The WIZ850io is an ideal option for users who want to develop their Internet...
Reference: RBD-1399
Operating Voltage: 12V DC Two separate LEDs for On/Off indication of the Relay Triggering input voltage 3.3V – 5V 4) Back EMF protection Equipped with high-current relay 10A@250VAC / 10A@30VDC It can control both AC and DC appliances such as Solenoids, Motors, lights, fans, etc High-quality screw terminals (Terminal Block) provided (C, NC, NO) for quick...
Reference: RBD-2564
This MOSFET module with optoisolation uses the LR7843 N-Channel logic compatible MOSFET with ultra low Rds(on) for moderate to higher current low-side switching applications of up to 15A continuous. N-Channel logic compatible MOSFET with optoisolation and ultra low 3.3mΩ Rds(on)
Reference: RBD-0358
Dimensions: 11×15 x 2 (L x W x H) mm Weight: 1gm Mutual transform between 5V TTL and 3.3V TTL Two channels of logic and high voltage low voltage logic can two-way transform Portable and lightness, with 2 rows 4 pin contact pins
Reference: RBD-0658
Standard interface layout, compatible with a variety of Arduinos such as the Pro Mini Original FTDI FT232 chip, stable performance USB power has current protection, using 500MA self-restore fuse RXD/TXD transceiver communication indicator With power, sending, receiving indicator, working status LED indicators Mini USB Port Connection Support 3.3V, 5V...
Reference: RBD-2758
With this module you can easily measure sound with an analog pin on your Arduino or other microcontroller. The module has an automatic gain/amplification (ACG) of the microphone: The module amplifies sounds with a low volume more, and sounds with a higher volume less.
Reference: RBD-2456
Breakout adapter includes a built-in 3.3V regulator and easy header hookup.
Reference: RBD-2305
WS2812B RGB LED 8-Bit Ring with individually addressable LEDs Features 8 WS2812 5050 RGB LEDs in a compact 32mm outer diameter circular board Constant current drive (~18mA per LED) for consistent brightness at 5V Requires a microcontroller with an 8MHz or faster processor for precise control Equipped with solder pads and mounting holes for easy integration
Reference: RBD-1856
Dual channel stereo, high output power (3 w + 3 w power @ 5V and 4 ohms load).. Double panel wiring solves crosstalk. Super mini design allows it to be easily placed in a variety of digital products. 3W Output at 10% THD with a 4ΩLoad and 5V Power Supply. Filterless, Low Quiescent Current and Low EMI and Low Noise. Short Circuit Protection and Thermal...
Reference: RBD-1400
4-Channel Relay interface board and each one needs 15-20mA Driver Current. Both controlled by 12V and 5V input Voltage. Equipped with high-current relay, AC250V 10A ; DC30V 10A. Standard interface that can be controlled directly by microcontroller (Arduino, 8051, AVR, PIC, DSP, ARM, ARM, MSP430, TTL logic active low). Indication LED’s for Relay output...
Reference: RBD-2206
Analog piezoelectric ceramic vibration module Measures the extent of vibration Proportional to the strength of shock or vibration Interface type: Analog Output Dimensions: 30 (L) x 23 (W) x 17 (H) Weight: 5g
Reference: RBD-1594
29mm diameter 10 LED Dimmable 50-degree viewing angle
Reference: RBD-3275
The IRF540 4-Way Isolated MOSFET Switch Power Module is a high-efficiency switching device designed for controlling DC circuits with high current and voltage ratings. It is ideal for applications such as motor drives, LED dimming, switching power supplies, and other DC load controls. Unlike traditional relays, this MOSFET switch module operates without...
Reference: RBD-0663
Power supply voltage(VCC): 2.0, 3, 5.5 V. Output high VOH: 0.8VCC V Output low VOL: 0.3VCC V Response time (touch mode) : 60 mS Response time (low power mode) : 220 mS Can replace the traditional touch of a button Four M2 screws positioning holes for easy installation RoboticsBD
Reference: RBD-3121
The CJMCU Virtual Keyboard module is an advanced tool ideal for penetration testers and security enthusiasts. Powered by the ATMEGA32U4 chip, this module functions as a versatile virtual keyboard capable of executing custom scripts and payloads, much like the popular RubberDucky devices. With built-in TF (microSD) memory support, this device allows...
Reference: RBD-1750
Operating Voltage: 3- 12 VDC Amplification: Adjustable 1.5~1000 times Signal Input Voltage Range: 100µV~300mV Signal Output Range: 100µV~300mV
Reference: RBD-2672
MCP3008 is one of the famous Analog to Digital converter IC. This chip will add 8 channels of 10-bit analog input to your microcontroller or microcomputer project. It's super easy to use, and uses SPI so only 4 pins are required. We chose this chip as a great accompaniment to the Raspberry Pi computer, because its fun to have analog inputs but the Pi does...
Reference: RBD-1840
The DS1302 trickle-charge timekeeping chip module with battery backup A real-time clock/calendar and 31 bytes of static RAM. Communicates with a microprocessor via a simple serial interface. Real-time clock/calendar provides seconds, minutes, hours, day, date, month, and year information. Note: Batteries not included.
Reference: RBD-0040
Bluetooth 2.0 Module Based on CSR BC04 Chip – Ideal for reliable wireless communication. Slave Mode Only – Perfect for receiving data from smartphones or other master devices. Wide Operating Voltage (3.3V to 6V) with onboard regulator for easy integration. Built-in 2.4GHz PCB Antenna – Supports wireless range up to 10 meters. Simple UART Interface (VCC,...
Reference: RBD-2416
USB to Serial Conversion: Reliable CH340G USB to UART interface for seamless communication. Dual Voltage Output: Provides 5V and 3.3V outputs for versatile usage. Compact Design: Miniature size for easy installation in tight spaces. Stable Performance: Built with the CH340G chip, known for reliability and stability. Wide Compatibility: Supports flashing...
Reference: RBD-1870
Compatible with 3.3V and 5.0V power supply. Compatible with 3.3V and 5.0V signal. Semi-hole pads, onboard module, thin PCB, having a thickness of 0.8mm. Has RXD, TXD signal indicator light, monitor send and receive status.
Reference: RBD-2741
Module mounts an 8MB serial flash chip for easy use with breadboards.
Reference: RBD-3049
The VC-02-Kit is a development board designed for the VC-02 module, and it is a shared the same board with the VC-01-Kit. The development board integrates the CH340C serial port to a USB chip, providing a basic debugging interface and USB upgrade interface, designing wake-up light and cold and cooling lamp, providing status indication and control...
Reference: RBD-3048
This Industrial Grade USB to RS485 Converter is designed to provide seamless data transmission between USB and RS485 interfaces, making it a reliable and versatile solution for various industrial applications. Equipped with the CH340 chip, it ensures fast and stable communication with RS485-compatible devices. The internal components shown in the picture...
Reference: RBD-0768
Size: 5mm Color: RED Head Shape: Round Lens Appearance: Transparent
Reference: RBD-2628
Connect and Build: Construct your robotic chassis with ease using this sturdy T connector. 2.5mm Acrylic: Offers durability and lightweight design for versatile robot creation. Right-Angle Connection: Creates a T-shaped junction for flexible chassis assembly. Universal Design: Compatible with 2WD, 4WD, and 6WD chassis configurations.
Reference: RBD-0836
Model: 14500 Type: Li-Ion Battery Mark Capacity: 850mah Nominal Voltage: 3.7v Color: Blue Weight: 17g Rechargeable Battery: Yes Note: It's a clone battery so the ampere couldn't be guaranteed.
Reference: RBD-0757
Working Voltage:2.7~5.5V Forward Voltage: 1.2-1.5V Forward Current: 100mA
Reference: RBD-0986
Ultra-thin design & adhesive backing provides easy integration to any project. Excellent price-performance ratio. Easy communication with any microcontroller 5 pins 2.54mm pitch connector, 4x 4type 16 keys. Sticker can peel off for adhesive mounting.
Reference: RBD-1954
Maximum Output Current: 3A MAX Conversion efficiency: can up to 97.5% Switch frequency: 500KHz Operating temperature: Industrial grade (-40 ° to + 85 °) Improve conversion efficiency
Reference: RBD-0761
Breadboard friendly Mounting Style: Through Hole Mounting Direction: Vertical
Reference: 0031
3 Types Available (Please select from option) 1. Male to Male 2. Male to Female 3. Female-Female
Reference: RBD-0313
Low power consumption, Low cost, and Compact size Read and write chip Fully integrated at 13.56MHz
Reference: RBD-1098
Interface: I2C Operating Voltage: 3-5VDC Ports: 8-bit Parallel Ports Can be used with Arduino and Raspberry Pi
Reference: RBD-1191
Internal filter for PCM frequency. Inner shield, good anti-interference ability. High immunity against ambient light. Improved shielding against electric field disturbance 3.0V or 5.0V supply voltage; low power consumption. TTL and CMOS compatibility. Suitable transmission code:NEC code,RC5 code. Universal receiver. 38 KHz. Infrared remote control receiver.
Reference: RBD-0948
Built-in Flash: 32Mbit Power supply: 5V WiFi protocol: IEEE 802.11 b/g/n Peripheral interface: UART/GPIO/ADC/DAC/SDIO/PWM/I2C/I2S Logic level: 3.3V A high-quality USB cable is essential for this board to ensure sufficient current supply; otherwise, your board may not be recognized by the Windows Device Manager. Please avoid using mobile phone cables and...
Reference: RBD-0755
Size: 5mm Color: Green Head Shape: Round Lens Appearance: Transparent
Module can be used to expand the digital I/O of an MCU using the I2C bus.
