What are I O expanders?
NXP’s general-purpose input/output (GPIO) expanders are a simple, cost-effective way to monitor and control several peripheral signals. They make it easy for designers to add extra I/O to their design and thereby free up the microprocessor’s GPIO for other, more important functions.
What is a I2C expander?
I2C – GPIO Port Expander The I/O expander adds additional GPIO ports. These can be used as both inputs, and outputs at either 3.3V or 5V. I2C is a two wire bus, the connections are called SDA (Serial Data) and SCL (Serial Clock).
How do I connect my Arduino to MCP23017?
Simple Netlist connections The following netlist and diagram show you how connecting the MCP23017 to the Arduino is very simple. Connect pin #19 of the expander to Arduino pin 3 (interrupt input). Connect pin #18 of the expander through a ~10kohm resistor to 5V (reset pin, active low).
How do you use a MCP23017 I2C Port Expander with the Raspberry Pi?
Connect the SCL and SDA pins on the MCP23017 to the I2C pins on the Raspberry Pi hardware. Set the I2C device address of the MCP23017 to ‘0x20’ by grounding the A0, A1, A2 pins. Connect the RESET pin to the +5V voltage rail. Since MCP23017 is powered by +5V, the output pins show +5V when they are set to logic high.
How do I program PCF8574?
After connecting the I2C Module to LCD, connect the GND and VCC pins of the PCF8574 Module to GND and 5V pins of Arduino. Finally, the SDA and SCL Pins. Connect them to pins A4 and A5 pins of Arduino UNO respectively.
Are there any 16 bit GPIO expanders on the market?
The XRA1201, XRA1201P, XRA1203, XRA1207, XRA1403, and XRA1405 are 16-bit GPIO expanders. All of the XRA120x and XRA140x GPIO expanders have internal pull-up resistors on each I/O pin that can be individually enabled or disabled.
How does the expander work on the Arduino?
Connect pin #19 of the expander to Arduino pin 3 (interrupt input). Connect pins #15, 16 and 17 of the expander to Arduino ground (address selection) Connect pin #18 of the expander through a ~10kohm resistor to 5V (reset pin, active low).
Why do you need a GPIO expander for SPI?
They have an efficient data bus interface to reduce the I/O requirements of the MPU or MCU. This is typically a synchronous serial interface like SPI or I2C. They enable a designer to incorporate more I/O into a system than is available on the processor device they are using.
Can you use Arduino pins with ioabstraction?
Using IoAbstraction you can write a sketch / program that uses Arduino pins, shift registers and IO expander devices at the same time, very much like you’d normally use Arduino pins. This library also provides simple interrupt handling that again is consistent across Arduino, mbed and IO expander ICs.