Merge pull request #97 from jpirnay/feat-x3clock

feat: support x3 RTC chip
This commit is contained in:
jpirnay
2026-04-17 23:32:42 +02:00
committed by GitHub
2 changed files with 156 additions and 2 deletions
+156 -1
View File
@@ -1,9 +1,11 @@
#include "HalClock.h"
#include <Arduino.h>
#include <HalGPIO.h>
#include <Logging.h>
#include <Preferences.h>
#include <WiFi.h>
#include <Wire.h> // Needed for I2C communication with the RTC
#include <esp_private/esp_clk.h>
#include <esp_sntp.h>
#include <sys/time.h>
@@ -12,6 +14,38 @@
#include <cmath>
#include <cstdlib>
// ---- RTC / I2C configuration ----------------------------------------------
// Pins for ESP32-C3 (according to https://gist.github.com/CrazyCoder/1c5f846adee18e21f91e264601a6ddce)
static constexpr uint8_t DS3231_ADDRESS = 0x68;
// static constexpr int I2C_SDA = 8;
// static constexpr int I2C_SCL = 9;
static uint8_t bin2bcd(uint8_t val) { return val + 6 * (val / 10); }
static uint8_t bcd2bin(uint8_t val) { return val - 6 * (val >> 4); }
/**
* Convert struct tm (interpreted as UTC) to Unix epoch seconds.
* Replaces mktime(), as mktime considers the local timezone (TZ).
*/
static time_t timegm_compat(const struct tm* tm) {
int32_t year = tm->tm_year + 1900;
int32_t month = tm->tm_mon; // 0-11
// Helper calculation: days since the beginning of the year
static const uint16_t days_before_month[] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
// Days since 1970 (considering leap years)
time_t days = (year - 1970) * 365 + (year - 1969) / 4;
days += days_before_month[month];
// Leap year correction for the current year (no extra day before March)
if (month > 1 && (year % 4 == 0)) {
days++;
}
days += tm->tm_mday - 1;
return days * 86400 + tm->tm_hour * 3600 + tm->tm_min * 60 + tm->tm_sec;
}
// ---- RTC-memory state (survives deep sleep, not cold boot) ----------------
static constexpr uint32_t CLOCK_RTC_MAGIC = 0xC10C4B1D;
@@ -169,11 +203,100 @@ static time_t nvsReadSyncTime() {
// ---- internal helpers -----------------------------------------------------
static bool initExternalRTC();
static float readExternalTemp();
static float readChipTemperatureC() {
// ESP32 and ESP32-C3 use the internal ADC temperature sensor.
if (initExternalRTC()) {
return readExternalTemp();
}
return (float)temperatureRead();
}
// ---- New internal helpers for DS3231 ---------------------------------------
static bool initExternalRTC() {
static bool initialized = false;
static bool exists = false;
if (initialized) return exists;
initialized = true;
if (!gpio.deviceIsX3()) {
LOG_DBG("CLK", "Skipping DS3231 init on non-X3 board");
return false;
}
// Wire has already been initialized; no need to call Wire.begin(I2C_SDA, I2C_SCL);
Wire.beginTransmission(DS3231_ADDRESS);
if (Wire.endTransmission() == 0) {
exists = true;
LOG_INF("CLK", "DS3231 Hardware via I2C found.");
} else {
LOG_INF("CLK", "No DS3231 found.");
}
return exists;
}
// Write time to DS3231
static void writeExternalRTC(time_t t) {
struct tm timeinfo;
gmtime_r(&t, &timeinfo); // DS3231 gets usually operated in UTC
Wire.beginTransmission(DS3231_ADDRESS);
Wire.write(0x00); // start-register (seconds)
Wire.write(bin2bcd(timeinfo.tm_sec));
Wire.write(bin2bcd(timeinfo.tm_min));
Wire.write(bin2bcd(timeinfo.tm_hour));
Wire.write(bin2bcd(0)); // weekday (ignored here)
Wire.write(bin2bcd(timeinfo.tm_mday));
Wire.write(bin2bcd(timeinfo.tm_mon + 1));
Wire.write(bin2bcd(timeinfo.tm_year - 100)); // DS3231 stores years since 2000
Wire.endTransmission();
}
// Read time from DS3231
static time_t readExternalRTC() {
Wire.beginTransmission(DS3231_ADDRESS);
Wire.write(0x00);
if (Wire.endTransmission() != 0) return 0;
Wire.requestFrom(DS3231_ADDRESS, (uint8_t)7);
if (Wire.available() < 7) return 0;
struct tm timeinfo = {};
timeinfo.tm_sec = bcd2bin(Wire.read() & 0x7F);
timeinfo.tm_min = bcd2bin(Wire.read());
timeinfo.tm_hour = bcd2bin(Wire.read() & 0x3F);
Wire.read(); // Wochentag überspringen
timeinfo.tm_mday = bcd2bin(Wire.read());
timeinfo.tm_mon = bcd2bin(Wire.read()) - 1;
timeinfo.tm_year = bcd2bin(Wire.read()) + 100;
timeinfo.tm_isdst = 0;
return timegm_compat(&timeinfo);
}
// Read temperature (Register 0x11)
static float readExternalTemp() {
Wire.beginTransmission(DS3231_ADDRESS);
Wire.write(0x11);
if (Wire.endTransmission() != 0) {
return 0.0f;
}
int count = Wire.requestFrom(DS3231_ADDRESS, (uint8_t)2);
if (count < 2) {
return 0.0f;
}
int8_t msb = Wire.read();
uint8_t lsb = Wire.read();
return (float)msb + (lsb >> 6) * 0.25f;
}
// ----
static void setSystemClock(time_t epoch) {
struct timeval tv = {};
tv.tv_sec = epoch;
@@ -231,6 +354,10 @@ static double computeCorrectedElapsedSec(uint64_t lpNow, float tempNow) {
/// Capture current time + LP timer into RTC memory, and epoch into NVS.
static void capture(bool lpValid) {
rtcEpoch = time(nullptr);
// Update DS3231 only when the current time is authoritative.
if (initExternalRTC() && !clockApproximate) {
writeExternalRTC(rtcEpoch);
}
rtcLpTimeUs = esp_clk_rtc_time();
rtcSlowCal = esp_clk_slowclk_cal_get();
rtcTemperatureC = readChipTemperatureC();
@@ -275,6 +402,8 @@ bool syncNtp() {
return false;
}
// NTP sync yields authoritative time; allow DS3231 to be updated.
clockApproximate = false;
capture(false);
nvsWriteSyncTime(rtcEpoch);
@@ -337,8 +466,19 @@ void saveBeforeSleep(bool keepLpAlive) {
}
void restore() {
rtcDriftScale = nvsReadDriftScale();
// PRIORITY 1: DS3231 (Hardware-RTC)
if (initExternalRTC()) {
time_t rtcTime = readExternalRTC();
if (rtcTime > 1577836800) { // Check if time is after 2020 (plausible timestamp)
setSystemClock(rtcTime);
rtcEpoch = rtcTime;
clockApproximate = false;
LOG_INF("CLK", "Got time from DS3231.");
return;
}
}
rtcDriftScale = nvsReadDriftScale();
const bool lpValid = (rtcClockFlags & CLOCK_RTC_FLAG_LP_VALID) != 0;
if (rtcValid() && lpValid) {
// RTC memory survived — we woke from deep sleep.
@@ -411,6 +551,21 @@ time_t now() {
}
void updatePeriodic() {
// DS3231 (if present) has priority, synchronize the system time
// every 10 minutes directly against the RTC, instead of calculating.
if (initExternalRTC()) {
unsigned long nowMs = millis();
if (nowMs - lastPeriodicUpdateMs >= PERIODIC_UPDATE_INTERVAL_MS) {
time_t rtcTime = readExternalRTC();
if (rtcTime > 1577836800) { // Check if time is after 2020 (plausible timestamp)
lastPeriodicUpdateMs = nowMs;
setSystemClock(rtcTime);
LOG_DBG("CLK", "Systemtime has been taken from DS3231");
}
}
return;
}
if (!isSynced()) {
return;
}
-1
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@@ -26,7 +26,6 @@ build_flags =
-DEINK_DISPLAY_SINGLE_BUFFER_MODE=1
-DDISABLE_FS_H_WARNING=1
-DDESTRUCTOR_CLOSES_FILE=1
;-DENABLE_IMAGE_DITHERING_EXTENSION ; dont enable by default, as it increases code size and may not be needed for all images
# https://libexpat.github.io/doc/api/latest/#XML_GE
-DXML_GE=0
-DXML_CONTEXT_BYTES=1024