Raspberry Pi AW9523B IO Expansion Board User Guide

Overview

AW9523B use I2C interface, allows using 4 expansion boards at the same time by modifying the i2c addrtess, expand up to 64 I/O ports.

Specification

ControllerAW9523B
Operating voltage3.3V/5V
IOs16
InterfaceI2C

Interfaces

PINFUNTION
VCCPower input(3.3V/5V)
GNDGND
SDAI2C Data input
SCLI2C Clock input
INTIntrrupt output
RSTReset

RPI User Guides

Enable I2C Interface

Open a terminal and run the following commands:

sudo raspi-config 
Choose Interfacing Options -> I2C ->yes 

Reboot Raspberry Pi:

sudo reboot


Install Libraries

  • Install BCM2835 libraries
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.64.tar.gz
tar zxvf bcm2835-1.60.tar.gz 
cd bcm2835-1.64/
sudo ./configure
sudo make
sudo make check
sudo make install
#For more details, please refer to http://www.airspayce.com/mikem/bcm2835/
  • Install WiringPi libraries
sudo apt-get install wiringpi

#For Pi 4, you need to update it:
cd /tmp
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
gpio -v
#You will get 2.52 information if you install it correctly

Download Examples

Open Raspberry Pi termianl and run the following commands to download the examples:

sudo apt-get install p7zip-full -y
sudo wget  https://www.waveshare.com/w/upload/b/b8/AW9523B-IO-Expansion-Board-Code.7z
7z x AW9523B-IO-Expansion-Board-Code.7z -O./AW9523B-IO-Expansion-Board-Code
cd AW9523B-IO-Expansion-Board-Code/RaspberryPi/

Hardware connection

Connect to Raspberry Pi
PCF8574Raspberry PiFunction
Board order
VCC5VPower input
GNDGNDGND
SDA3I2C Data input
SCL5I2C clock input
INT16Interrupt input (could NC)
RST18Reset module (could NC)


Test the example

Please first negative to 'AW9523B-IO-Expansion-Board-Code/RaspberryPi/' directly by cd command before you run the codes;;

C codes

  • Compile the codes and run it
cd C
sudo make clean
sudo make 
sudo ./main

The examples use interrupt by default, if you want to disable the interrupt function, please add the following lines to /boot/config.txt, it will set the gpio23 to pull-up mode.

gpio=23=pu

python

Run the following commands:

cd python
sudo python AW9523B.py

Expected result

Connect the PAx pin to PBx pin, for example, connect PA0 to PB0 by cables. The PAx pins are set as output, and PBx are set as input. The status of PAx pins output toggle every 550ms in order like water lamp, every time the PAx pins toggle, it all cause the PBx pin to interrupt and printed the status to the terminal.

Arduino User Guides

The provided examples and hardware connections are based on Arduino UNO R3. For other Arduino boards, you may need to modify the connection or codes

Hardware Connection

You can connect the board according to the table

Connect to Arduino
PCF8574ArduinoFunction
VCC5VPower input
GNDGNDGND
SDASDAI2C data input
SCLSCLI2C clock input
INTD3interrupt output
RSTD4reset


Install Arduino IDE(Windows)

arduino IDE Installation Guides

Run the Codes

Download the examples from Demo codes, unzip the archive, and enter the AW9523B-IO-Expansion-Board-Code directory. Copy the AW9523B-Arduino-Library folder to the libraries directory which is under the installation path, generally, the path is C:\Program Files (x86)\Arduino\libraries
Open the Ariduino IDE software, Tools choose UNO, then open the examples from File-> Example

Build and upload the eamples, then open the serial monitor to check the logs

Expected

Connect the PAx pin to PBx pin, for example, connect PA0 to PB0 by cables. The PAx pins are set as output, and PBx are set as input. The status of PAx pins output toggle every 550ms in order like water lamp, every time the PAx pins toggle, it all causes the PBx pin to interrupt and printed the status to the serial monitor.

STM32 User Guides

The example and related hardware connection are based on STM32F103RBT6. If you want to use other STM32 board, you may need to change the hardare connection and codes.

Hardware Connection

Connect to STM32F103RB
PCF8574STM32Function
VCC3.3VPower input
GNDGNDGND
SDAPB9I2C data input
SCLPB8I2C clock input
INTPB8Interrupt
RSTPB8Reset


Run the codes

The examples is based on HAL libraries. Download the Demo codes,find the STM32 directory. Open the PCF8574 IO Expansion Board.uvprojx file from STM32\STM32F103RB\MDK-ARM folder

Open the main.c file, rebuild the codes and download.

After downloading, Run the SSCOM software, choose the related COM and set the baud rate to 115200, check the logs.

Exptect result

1、Use a multimeter to measure the voltage of every IOs, the P0~P3 are High and P4 ~ P7 are Low.
2、Open the SSCOM software, the statgus of IOs are printed on the software.

Price: $6.89
Part Number: AW9523B IO Expansion Board
Brand: Spotpear
SKU: 0102134