byte BlinkPlug::state () {
byte saved = leds;
ledOff(1+2);
byte result = !digiRead() | (!digiRead2() << 1);
ledOn(saved);
return result;
}
uint8_t SHT21::writeByte(uint8_t value) const {
mode(OUTPUT);
for (uint8_t i = 0x80; i != 0; i >>= 1) {
digiWrite(value & i);
clock(1);
clock(0);
}
release();
clock(1);
uint8_t error = digiRead();
clock(0);
return error;
}
uint8_t SHT21::readByte(uint8_t ack) const {
uint8_t value = 0;
for (uint8_t i = 0x80; i != 0; i >>= 1) {
clock(1);
if (digiRead())
value |= i;
clock(0);
}
mode(OUTPUT);
digiWrite(!ack);
clock(1);
clock(0);
release();
return value;
}
uint16_t Port::shiftRead(uint8_t bitOrder, uint8_t count) const {
uint16_t value = 0, mask = bit(LSBFIRST ? 0 : count - 1);
for (uint8_t i = 0; i < count; ++i) {
digiWrite2(1);
delayMicroseconds(5);
if (digiRead())
value |= mask;
if (bitOrder == LSBFIRST)
mask <<= 1;
else
mask >>= 1;
digiWrite2(0);
delayMicroseconds(5);
}
return value;
}
uint8_t SHT21::measure(uint8_t type, void (*delayFun)()) {
start();
writeByte(type == TEMP? MEASURE_TEMP : MEASURE_HUMI);
for (uint8_t i = 0; i < 250; ++i) {
if (!digiRead()) {
meas[type] = readByte(1) << 8;
meas[type] |= readByte(1);
uint8_t flipped = 0;
for (uint8_t j = 0x80; j != 0; j >>= 1) {
flipped >>= 1;
}
if (readByte(0) != flipped)
break;
return 0;
}
if (delayFun)
delayFun();
else
delay(1);
}
