timesync.cpp: code sanitization and documentation

This commit is contained in:
Verkehrsrot 2019-07-24 20:09:36 +02:00
parent 43c06be8e8
commit b7df5bce1a

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@ -110,14 +110,8 @@ void process_timesync_req(void *taskparameter) {
}
} // end of for loop to collect timestamp samples
// lock I2C bus and application irq to ensure accurate timing
// mask application irq to ensure accurate timing
mask_user_IRQ();
// if (!I2C_MUTEX_LOCK()) {
// ESP_LOGW(TAG, "[%0.3f] Timesync handshake error: i2c bus locking
// failed",
// millis() / 1000.0);
// goto finish; // failure
//}
// average time offset over all collected diffs
time_offset_ms /= TIME_SYNC_SAMPLES;
@ -137,8 +131,7 @@ void process_timesync_req(void *taskparameter) {
setMyTime(time_to_set, time_to_set_fraction_msec);
finish:
// end of time critical section: release I2C bus and app irq
// I2C_MUTEX_UNLOCK();
// end of time critical section: release app irq lock
unmask_user_IRQ();
timeSyncPending = false;
@ -182,17 +175,17 @@ int recv_timesync_ans(uint8_t seq_no, uint8_t buf[], uint8_t buf_len) {
else { // we received a probably valid time frame
uint8_t k = seq_no % TIME_SYNC_SAMPLES;
uint16_t timestamp_msec; // convert 1/250th sec fractions to ms
uint32_t timestamp_sec, *timestamp_ptr;
// fetch timeserver time from 4 bytes containing the UTC seconds since
// unix epoch. Octet order is big endian.
timestamp_ptr = (uint32_t *)buf;
timestamp_sec = __builtin_bswap32(*timestamp_ptr); // note: this is platform dependent (msb/lsb)
// the 5th byte contains the fractional seconds in 2^-8 second steps
timestamp_msec = 4 * buf[4];
// (= 1/250th sec), we convert this to ms
uint16_t timestamp_msec = 4 * buf[4];
// pointers to 4 bytes 4 bytes containing UTC seconds since unix epoch, msb
uint32_t timestamp_sec, *timestamp_ptr;
// convert buffer to uint32_t, octet order is big endian
timestamp_ptr = (uint32_t *)buf;
// swap byte order from msb to lsb, note: this is platform dependent
timestamp_sec = __builtin_bswap32(*timestamp_ptr);
// construct the timepoint when message was seen on gateway
time_sync_rx[k] += seconds(timestamp_sec) + milliseconds(timestamp_msec);