Pin# | Type | Parameters |
Pin#1 | SCL/SCK | It is a Serial clock input. |
Pin#2 | SDA/SI | It is a Serial data I/O (MCP23008)/Serial data input (MCP23S08) pin. |
Pin#3 | A2/SO | It is a hardware address input (MCP23008)/Serial data output (MCP23S08). It (A2) must be biased externally. |
Pin#4 | A1 | It is a Hardware address input. It Must be biased externally. |
Pin#5 | A0 | It is a Hardware address input. It Must be biased externally. |
Pin#6 | RESET | This is an external reset input. |
Pin#7 | NC/CS | No connect (MCP23008)/External chip select input (MCP23S08). |
Pin#8 | INT | It is an Interrupt output. It Can be configured for active-high, active-low or open-drain. |
Pin#9 | VSS | It is used for Ground. |
Pin#10 | GP0 | It is a Bidirectional I/O pin. It can be enabled for interrupt-on-change and/or internal weak pull-up resistor. |
Pin#11 | GP1 | It is a Bidirectional I/O pin. It can be enabled for interrupt-on-change and/or internal weak pull-up resistor. |
Pin#12 | GP2 | It is a Bidirectional I/O pin. It can be enabled for interrupt-on-change and/or internal weak pull-up resistor. |
Pin#13 | GP3 | It is a Bidirectional I/O pin. It can be enabled for interrupt-on-change and/or internal weak pull-up resistor. |
Pin#14 | GP4 | It is a Bidirectional I/O pin. It can be enabled for interrupt-on-change and/or internal weak pull-up resistor. |
Pin#15 | GP5 | It is a Bidirectional I/O pin. It can be enabled for interrupt-on-change and/or internal weak pull-up resistor. |
Pin#16 | GP6 | It is a Bidirectional I/O pin. It can be enabled for interrupt-on-change and/or internal weak pull-up resistor. |
Pin#17 | GP7 | It is a Bidirectional I/O pin. It can be enabled for interrupt-on-change and/or internal weak pull-up resistor. |
Pin#18 | VDD | Power pin. |
Pin#19 | N/C | N/C |
First, we discuss the component of projects.
For input supply, we have connected +5V to Vdd and Vss to GND.
Now, connect pin no 1 of the MCP23008, which is SCL to analog pin no 5 of Arduino. This provides clock synchrony between Arduino and the I/O port expander chip.
After this, we have connected pin no 2 of MCP23008, which is SDA to analog pin no 4 of Arduino. This connection allows data transfer between the Arduino and the I/O port expander chip.
In this project there is no use of interrupts pin, so leave INT pin unconnected.
We are not using the RESET pin, we connect it to +5V. If you want to use it, you just connect it with digital pin no the Arduino. If you want to reset all outputs than you draw this pin low in cade.
After that, we will connect address pin A0, A1, and A2, to ground. It makes the address of these 3 pins 000.
So, friends, that was all about MCP23008, if you have any question about it please ask in comments, I will solve your problems. Thanks for reading. Take care until the next tutorial.
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