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#include "wiring_shift_mod.h"
#define CLOCK_TYPE CLOCK_INVERT
#define CLOCK_DELAY_US 1
const int strobe_pin = 4;
const int clock_pin = 16;
const int data_pin = 17;
void setup()
{
pinMode(strobe_pin, OUTPUT);
pinMode(clock_pin, OUTPUT);
pinMode(data_pin, OUTPUT);
sendCommand(0x8f); // activate
reset();
}
void loop()
{
uint8_t buttons = readButtons();
for(uint8_t position = 0; position < 8; position++)
{
uint8_t mask = 0x1 << position;
setLed(buttons & mask ? 1 : 0, position);
}
}
void sendCommand(uint8_t value)
{
digitalWrite(strobe_pin, LOW);
shiftOutMod(data_pin, clock_pin, LSBFIRST, CLOCK_TYPE, CLOCK_DELAY_US, value);
digitalWrite(strobe_pin, HIGH);
}
void reset()
{
sendCommand(0x40); // set auto increment mode
digitalWrite(strobe_pin, LOW);
shiftOutMod(data_pin, clock_pin, LSBFIRST, CLOCK_TYPE, CLOCK_DELAY_US, 0xc0); // set starting address to 0
for(uint8_t i = 0; i < 16; i++)
{
shiftOutMod(data_pin, clock_pin, LSBFIRST, CLOCK_TYPE, CLOCK_DELAY_US, 0x00);
}
digitalWrite(strobe_pin, HIGH);
}
uint8_t readButtons(void)
{
uint8_t buttons = 0;
digitalWrite(strobe_pin, LOW);
shiftOutMod(data_pin, clock_pin, LSBFIRST, CLOCK_TYPE, CLOCK_DELAY_US, 0x42);
pinMode(data_pin, INPUT);
for (uint8_t i = 0; i < 4; i++)
{
uint8_t v = shiftInMod(data_pin, clock_pin, LSBFIRST, CLOCK_TYPE, CLOCK_DELAY_US) << i;
buttons |= v;
}
pinMode(data_pin, OUTPUT);
digitalWrite(strobe_pin, HIGH);
return buttons;
}
void setLed(uint8_t value, uint8_t position)
{
pinMode(data_pin, OUTPUT);
sendCommand(0x44);
digitalWrite(strobe_pin, LOW);
shiftOutMod(data_pin, clock_pin, LSBFIRST, CLOCK_TYPE, CLOCK_DELAY_US, 0xC1 + (position << 1));
shiftOutMod(data_pin, clock_pin, LSBFIRST, CLOCK_TYPE, CLOCK_DELAY_US, value);
digitalWrite(strobe_pin, HIGH);
}
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