The MCP23017-E/SO is a part from Microchip Technology, which specializes in developing microcontrollers, memory, analog, and interface products. The MCP23017-E/SO is an I2C I/O Expander with 16-bit input/output, which expands the number of I/O pins for microcontrollers with limited GPIO.
Here is a detai LED explanation of the MCP23017-E/SO's pin function specifications and circuit principle instructions, along with a comprehensive pin function list and FAQ. This is based on the MCP23017 family in the SOIC-28 package.
MCP23017-E/SO Pin Function Overview
Package Type: SOIC-28 (28 Pins) Pin Count: 28 Pin Description: Below is the detailed list of all pins, their respective functions, and explanations for each. Pin No. Pin Name Function Description 1 VSS Ground (GND) 2 GPA0 General Purpose I/O Pin A0 (Input/Output) 3 GPA1 General Purpose I/O Pin A1 (Input/Output) 4 GPA2 General Purpose I/O Pin A2 (Input/Output) 5 GPA3 General Purpose I/O Pin A3 (Input/Output) 6 GPA4 General Purpose I/O Pin A4 (Input/Output) 7 GPA5 General Purpose I/O Pin A5 (Input/Output) 8 GPA6 General Purpose I/O Pin A6 (Input/Output) 9 GPA7 General Purpose I/O Pin A7 (Input/Output) 10 VDD Supply Voltage (Typically 2.5V - 5.5V) 11 GPB0 General Purpose I/O Pin B0 (Input/Output) 12 GPB1 General Purpose I/O Pin B1 (Input/Output) 13 GPB2 General Purpose I/O Pin B2 (Input/Output) 14 GPB3 General Purpose I/O Pin B3 (Input/Output) 15 GPB4 General Purpose I/O Pin B4 (Input/Output) 16 GPB5 General Purpose I/O Pin B5 (Input/Output) 17 GPB6 General Purpose I/O Pin B6 (Input/Output) 18 GPB7 General Purpose I/O Pin B7 (Input/Output) 19 RESET Active Low Reset Pin (Resets the device when pulled low) 20 INTB Interrupt Output for Port B (Active Low when an interrupt occurs) 21 INTA Interrupt Output for Port A (Active Low when an interrupt occurs) 22 SCL I2C Clock Line (Input) 23 SDA I2C Data Line (Input/Output) 24 A2 Address Pin 2 (Used for setting the I2C address) 25 A1 Address Pin 1 (Used for setting the I2C address) 26 A0 Address Pin 0 (Used for setting the I2C address) 27 GND Ground (GND) 28 NC No Connection (Can be left unconnected)Detailed Explanation of Pin Functions:
GPA0-GPA7 (Pins 2-9): These are the general-purpose input/output (GPIO) pins for Port A. They can be configured as input or output based on user needs. Each of these pins supports interrupt-on-change, allowing for efficient detection of state changes.
GPB0-GPB7 (Pins 11-18): These are the general-purpose GPIO pins for Port B, similar to Port A. They can be individually configured for input/output, and can also trigger interrupts.
VSS (Pin 1): Ground pin for the device, required for proper operation.
VDD (Pin 10): Supply voltage pin, typically between 2.5V and 5.5V.
RESET (Pin 19): Active-low pin used for resetting the device. When pulled low, the device is reset and returns to its initial configuration.
INTA (Pin 21), INTB (Pin 20): These pins are used to output interrupt signals for Port A and Port B, respectively. When an interrupt is triggered on any of the GPIO pins, the corresponding interrupt pin will go low to notify the microcontroller.
SCL (Pin 22): The I2C clock line, used to synchronize communication between the MCP23017 and the microcontroller or master device.
SDA (Pin 23): The I2C data line, used for data transfer between the MCP23017 and the microcontroller.
A0-A2 (Pins 24-26): Address pins used to configure the I2C address of the MCP23017. These pins are typically connected to either ground or VDD to set the 3-bit address.
NC (Pin 28): No connection, can be left floating or unconnected.
Frequently Asked Questions (FAQ):
1. What is the MCP23017-E/SO?
The MCP23017-E/SO is an I2C I/O expander with 16 I/O pins (8 on Port A and 8 on Port B). It is used to add more I/O pins to a microcontroller, allowing for greater control and connectivity.2. How do I connect the MCP23017 to a microcontroller?
The MCP23017 uses the I2C communication protocol, so you need to connect the SDA and SCL pins to the corresponding I2C data and clock lines on the microcontroller.3. What is the voltage range for the MCP23017-E/SO?
The MCP23017 operates with a supply voltage of 2.5V to 5.5V.4. Can I use the MCP23017 to control LEDs?
Yes, the GPIO pins of the MCP23017 can be configured as outputs to control LEDs.5. How can I trigger interrupts on the MCP23017?
Interrupts can be triggered by enabling the interrupt-on-change feature for each pin. If the state of any GPIO pin changes, an interrupt is generated, which can be read from the INTA or INTB pins.6. What is the maximum current that the GPIO pins can source or sink?
Each GPIO pin can source or sink a maximum of 25mA of current.7. What happens if I pull the RESET pin low?
Pulling the RESET pin low will reset the MCP23017, returning it to its initial configuration.8. How do I set the I2C address for the MCP23017?
The I2C address is set by connecting the A0, A1, and A2 pins to either ground or VDD. This creates a 3-bit address range, giving you 8 possible I2C addresses.9. How many GPIO pins does the MCP23017 provide?
The MCP23017 provides 16 GPIO pins, divided into two 8-bit ports (Port A and Port B).10. Can I use the MCP23017 for input-only applications?
Yes, the MCP23017 can be configured for input-only applications, where the GPIO pins are used to read signals from external devices.11. What is the maximum clock speed for the I2C communication?
The MCP23017 supports I2C communication at standard mode (100 kHz) and fast mode (400 kHz).12. Can I use the MCP23017 with 3.3V logic?
Yes, the MCP23017 is compatible with 3.3V logic levels.13. How do I handle multiple MCP23017 devices on the same I2C bus?
Each MCP23017 can have a unique I2C address, allowing multiple devices to be used on the same I2C bus.14. How do I configure the pins as input or output?
Pin configuration is done through the I/O direction registers (IODIRA and IODIRB) for Port A and Port B.15. What is the purpose of the INT pins (INTA and INTB)?
The INT pins are used to output interrupt signals when the state of any GPIO pin changes, indicating that an event has occurred.16. Can the MCP23017 operate without interrupts?
Yes, the MCP23017 can be used without interrupts if polling the GPIO pins for changes is preferred.17. Is there a way to read the status of GPIO pins?
Yes, the GPIO pins' status can be read from the GPIO registers (GPIOA and GPIOB).18. Can I use the MCP23017 to interface with switches?
Yes, the MCP23017 is ideal for interfacing with switches as it can detect changes in state and trigger interrupts.19. Does the MCP23017 support pull-up resistors on the inputs?
Yes, the MCP23017 supports internal pull-up resistors for input pins, which can be enabled via software.20. What is the difference between the MCP23017 and MCP23008?
The MCP23017 has 16 I/O pins (2 ports of 8 pins each), while the MCP23008 has 8 I/O pins (1 port).This detailed description provides all pin functions and a set of frequently asked questions related to the MCP23017-E/SO device.
