From 43c06be8e860c379a900183de4a99f2e57ed66b6 Mon Sep 17 00:00:00 2001 From: Verkehrsrot Date: Wed, 24 Jul 2019 13:52:24 +0200 Subject: [PATCH] improved code for time bytes evaluation --- src/timesync.cpp | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/src/timesync.cpp b/src/timesync.cpp index c3c78432..14dc1acc 100644 --- a/src/timesync.cpp +++ b/src/timesync.cpp @@ -112,8 +112,9 @@ void process_timesync_req(void *taskparameter) { // lock I2C bus and 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", + // if (!I2C_MUTEX_LOCK()) { + // ESP_LOGW(TAG, "[%0.3f] Timesync handshake error: i2c bus locking + // failed", // millis() / 1000.0); // goto finish; // failure //} @@ -137,7 +138,7 @@ void process_timesync_req(void *taskparameter) { finish: // end of time critical section: release I2C bus and app irq - //I2C_MUTEX_UNLOCK(); + // I2C_MUTEX_UNLOCK(); unmask_user_IRQ(); timeSyncPending = false; @@ -182,13 +183,13 @@ int recv_timesync_ans(uint8_t seq_no, uint8_t buf[], uint8_t buf_len) { uint8_t k = seq_no % TIME_SYNC_SAMPLES; uint16_t timestamp_msec; // convert 1/250th sec fractions to ms - uint32_t timestamp_sec; + uint32_t timestamp_sec, *timestamp_ptr; // fetch timeserver time from 4 bytes containing the UTC seconds since - // unix epoch. Octet order is big endian. Casts are necessary, because buf - // is an array of single byte values, and they might overflow when shifted - timestamp_sec = ((uint32_t)buf[3]) | (((uint32_t)buf[2]) << 8) | - (((uint32_t)buf[1]) << 16) | (((uint32_t)buf[0]) << 24); + // 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];