void keyscanner_main(void)
{
/* TODO: low power mode:
* When all keys reported up:
* DDR_PP = 0x11; PORT_PP = 0x00;
* Guarantee wake on TWI / any PORT_OD pin FALLING
* Sleep
*/
for (uint8_t pp = 0; pp < 8; ++pp) {
uint8_t pp_bitmask = _BV(pp);
_delay_ms(0.5);
DDR_PP = 0x00 ^ pp_bitmask;
PORT_PP = 0xFF ^ pp_bitmask;
_delay_ms(0.5);
uint8_t od_bits = PIN_OD;
/*
* Rollover conditions exist if:
* * Multiple OD pins are pulled low AND
* * Multiple PP pins are pulled low
*/
uint8_t nPp = popCount(~PIN_PP);
uint8_t nOd = popCount(~od_bits);
// Most of the time the keyboard will not be a rollover state
if (__builtin_expect(nPp > 1 && nOd > 1, 0)) {
continue;
}
// Debounce key state
uint8_t changes = debounce(od_bits, db + pp);
// Most of the time there will be no new key events
if (__builtin_expect(changes == 0, 1)) {
continue;
}
DISABLE_INTERRUPTS({
key_t key;
key.dataNumber = 0; // Set by I²C code (ringbuf.count != 0)
key.pp = pp;
for (int8_t od = 0; od < 8; od++) {
// Fewer than half the keys are expected to be down for each scanline
if (__builtin_expect(bit_is_set(changes, od), 0)) {
key.keyState = bit_is_clear(db[pp].state, od);
key.od = od;
ringbuf_append(key.val);
}
}
SET_INT(0);
});
}
int main() {
std::cout << popcount(0b00000000) << '\n';
std::cout << popcount(0b00000001) << '\n';
std::cout << popcount(0b00100001) << '\n';
std::cout << popcount(0b11111111) << '\n';
std::cout << popcount(0b1111111111110000) << '\n';
std::cout << popCount(0b00000000) << '\n';
std::cout << popCount(0b00000001) << '\n';
std::cout << popCount(0b00100001) << '\n';
std::cout << popCount(0b11111111) << '\n';
std::cout << popCount(0b1111111111110000) << '\n';
return 0;
}
uint16_t FID::rank(int pos, int digit) {
// bitmask: #tailing zero is (pos % smallSize)
// Ex. 11100000 #tailing zero is 5
const uint8_t mask = 0xff << (smallSize - (pos % smallSize));
const uint8_t lowerBit = originalBit[pos >> 3];
uint16_t result = blockLarge[pos / largeSize] + blockSmall[pos / smallSize] + popCount(lowerBit & mask);
if (digit == 0) result = static_cast<uint16_t>(pos - result);
return result;
}
