| 48 | } |
| 49 | |
| 50 | bool HalClock::getTime(uint8_t& hour, uint8_t& minute) const { |
| 51 | if (!_available) return false; |
| 52 | |
| 53 | const unsigned long now = millis(); |
| 54 | if (_lastPollMs != 0 && (now - _lastPollMs) < CLOCK_POLL_MS) { |
| 55 | hour = _cachedHour; |
| 56 | minute = _cachedMinute; |
| 57 | return true; |
| 58 | } |
| 59 | |
| 60 | // Read 3 bytes starting at register 0x00: seconds, minutes, hours |
| 61 | Wire.beginTransmission(I2C_ADDR_DS3231); |
| 62 | Wire.write(DS3231_SEC_REG); |
| 63 | if (Wire.endTransmission(false) != 0) { |
| 64 | if (!_hasCachedTime) return false; |
| 65 | _lastPollMs = now; |
| 66 | hour = _cachedHour; |
| 67 | minute = _cachedMinute; |
| 68 | return true; |
| 69 | } |
| 70 | Wire.requestFrom(I2C_ADDR_DS3231, (uint8_t)3); |
| 71 | if (Wire.available() < 3) { |
| 72 | if (!_hasCachedTime) return false; |
| 73 | _lastPollMs = now; |
| 74 | hour = _cachedHour; |
| 75 | minute = _cachedMinute; |
| 76 | return true; |
| 77 | } |
| 78 | |
| 79 | Wire.read(); // seconds — not needed |
| 80 | const uint8_t rawMin = Wire.read(); |
| 81 | const uint8_t rawHour = Wire.read(); |
| 82 | |
| 83 | _cachedMinute = bcdToDec(rawMin & 0x7F); |
| 84 | // Handle 12/24h mode: bit 6 high = 12h mode |
| 85 | if (rawHour & 0x40) { |
| 86 | // 12h mode: bit 5 = PM, bits 4-0 = hours (1-12) |
| 87 | uint8_t h12 = bcdToDec(rawHour & 0x1F); |
| 88 | bool pm = rawHour & 0x20; |
| 89 | if (h12 == 12) h12 = 0; |
| 90 | _cachedHour = pm ? (h12 + 12) : h12; |
| 91 | } else { |
| 92 | // 24h mode: bits 5-0 = hours (0-23) |
| 93 | _cachedHour = bcdToDec(rawHour & 0x3F); |
| 94 | } |
| 95 | _lastPollMs = now; |
| 96 | _hasCachedTime = true; |
| 97 | |
| 98 | hour = _cachedHour; |
| 99 | minute = _cachedMinute; |
| 100 | return true; |
| 101 | } |
| 102 | |
| 103 | bool HalClock::formatTime(char* buf, size_t bufSize, uint8_t utcOffsetQuarterHoursBiased, bool use12Hour) const { |
| 104 | if (bufSize < (use12Hour ? 9u : 6u)) return false; |