57 lines
1.6 KiB
C++
57 lines
1.6 KiB
C++
#include <Wire.h>
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/**
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* Arduino PF575/PCF8575 I2C I/O port exapander LED blink example
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*
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* Setup:
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*
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* 1. Connect A0, A1 and A2 to GND to set the address to 0x20.
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* 2. Connect SDL and SCL to the Arduino's I2C bus.
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* 3. Connect a LED to the P0 port of the I2C exapander.
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* In my setup I am using a PNP Transistor connected to 5V unsing
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* an resistor, the LED and the Arduino to make sure the LED gets
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* a current from Vcc and not from the I2C exapander port.
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*
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* This code is trying to explain how it works as simple as possible.
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* More detailed examples are found on the web. Search for pcf8575 and
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* you will find what you want.
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*/
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// Set I2C address
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int address = 0x20;
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void setup(){
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Wire.begin();
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// Set all ports as output
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//pf575_write(word(B11111111,B11111111));
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//delay(1000);
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pf575_write(word(B00000000,B00000000));
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}
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void loop(){
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int dTime = 1000;
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pf575_write(word(B00000001,B00000000));
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delay(dTime);
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pf575_write(word(B00000011,B00000000));
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delay(dTime);
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pf575_write(word(B00000111,B00000000));
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delay(dTime);
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pf575_write(word(B00001111,B00000000));
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delay(dTime);
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pf575_write(word(B00001110,B00000000));
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delay(dTime);
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pf575_write(word(B00001100,B00000000));
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delay(dTime);
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pf575_write(word(B00001000,B00000000));
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delay(dTime);
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pf575_write(word(B00000000,B00000000));
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delay(dTime);
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}
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// Function for writing two Bytes to the I2C expander device
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void pf575_write(uint16_t data) {
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Wire.beginTransmission(address);
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Wire.write(highByte(data));
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Wire.write(lowByte(data));
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Wire.endTransmission();
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}
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