Port Expander Board
Introduce easy I/O port expansion using a standard serial interface using the Port Expander Board. The board features an MCP23S17 16-bit I/O expander with serial interface. The SPI clock has a speed up to 10 MHz, which makes it highly suitable for higher throughput applications. The Interrupt-on-change feature can be considered as 8 separate external interrupts mapped on to the same interrupt vector. The Port Expander Board features jumpers that enable the user to determine the port expander.
- High speed 10MHz SPI to 16-bit I/O expander
- Based on the MCP23S17
- Three hardware address pins to allow up to eight devices on the bus
- 16 GPIO pins divided into two 8-bit ports
- For 5V systems
- Configurable interrupt output pins
- External reset input
- Selectable hardware address using jumpers
- Low standby current: 1
The MCP23S17 is a 16-bit input/output expander with SPI clock speeds up to 10 MHz. It comprises of multiple 8-bit configuration registers for input, output and polarity selection. It uses a SPI serial interface to communicate with the microcontroller provided on the development system. The 16-bit I/O port functionality consists of two 8-bit ports (PORTA and PORTB). MCP23S17 chip is used to convert data received from 16 additional pins and to transmit it to the microcontroller via two pins. Instead of 16 lines, the additional board is connected to the microcontroller through only four lines, known as data receive/transmit lines and two control lines.
The Port Expander Board features three jumpers: J0, J1 and J2. Designed to control the port expander's hardware address, these jumpers are placed in position marked 1, the address is 1. When placed in position marked 0, the address is 0. By default, all the jumpers are placed in position marked 0.
Port Expander Board User Manual
- Port Expander Board (1)