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AN1081
| Title |
Title
Interfacing a 4x4 Matrix Keypad with an 8-Bit GPIO Expander
|
|---|---|
| Name |
Name
AN1081
|
| Date |
Date
06/24/2015
|
| Description |
Description
This application note discusses interfacing a 4x4 matrix keypad with MCP23X08 8-Bit GPIO Expander. This application note references the MCP23X08/17 GPIO Expander Keypad/LCD Demo Board (GPIODM-KPLCD). GPIO Expanders provide easy I/O expansion using standard serial interfaces such as I2C and SPI. They are especially useful in applications where pin count is limited on the microcontroller unit (MCU) or if remote inputs / outputs (I/O's) are needed. It is best to think of an 8-bit GPIO Expander like adding another 8-bit wide digital port to the MCU. This application note does not detail all of the features of the MCP23X08. Refer to the MCP23008/MCP23S08 Data Sheet, "8-Bit I/O Expander with Serial Interface" (DS21919) for more information.
|
Silicon Products
| Title | Product | Title |
|---|---|---|
|
MCP23008
8-Bit I2C I/O Expander with Serial Interface
|
MCP23008 | 8-Bit I2C I/O Expander with Serial Interface |
|
MCP23S17
16-Bit SPI I/O Expander with Serial Interface
|
MCP23S17 | 16-Bit SPI I/O Expander with Serial Interface |
|
MCP23S08
8-Bit SPI I/O Expander with Serial Interface
|
MCP23S08 | 8-Bit SPI I/O Expander with Serial Interface |
|
MCP23017
16-Bit I2C I/O Expander with Serial Interface
|
MCP23017 | 16-Bit I2C I/O Expander with Serial Interface |