commit 22248e900af16b8c88414cec1540ef3716a46d4c
author James Kuszmaul <jabukuszmaul+collab@gmail.com> Fri Feb 23 16:46:51 2024 -0800
committer James Kuszmaul <jabukuszmaul+collab@gmail.com> Fri Feb 23 17:03:43 2024 -0800
tree 720c27b2dd7f674a5df1a46795ce2ac7b20acc88
parent f8b83394be75a7c8f26d36c8fae9b529130e8414

Account for socketcan providing realtime timestamps

We are getting realtime timestamps back, but were treating them as
monotonic times. Fix that.

Change-Id: Ib92ced05870dcfa7a476ce2509b28eb307bda5ac
Signed-off-by: James Kuszmaul <jabukuszmaul+collab@gmail.com>

frc971/can_logger/asc_logger.cc

diff --git a/frc971/can_logger/asc_logger.cc b/frc971/can_logger/asc_logger.cc
index 6848938..5282d13 100644
--- a/frc971/can_logger/asc_logger.cc
+++ b/frc971/can_logger/asc_logger.cc
@@ -12,11 +12,11 @@
 }
 
 void AscLogger::HandleFrame(const CanFrame &frame) {
-  if (!first_frame_monotonic_) {
-    aos::monotonic_clock::time_point time(
-        std::chrono::nanoseconds(frame.monotonic_timestamp_ns()));
+  if (!first_frame_realtime_) {
+    aos::realtime_clock::time_point time(
+        std::chrono::nanoseconds(frame.realtime_timestamp_ns()));
 
-    first_frame_monotonic_ = time;
+    first_frame_realtime_ = time;
 
     WriteHeader(output_, event_loop_->realtime_now());
   }
@@ -60,11 +60,11 @@
 }  // namespace
 
 void AscLogger::WriteFrame(std::ostream &file, const CanFrame &frame) {
-  aos::monotonic_clock::time_point frame_timestamp(
-      std::chrono::nanoseconds(frame.monotonic_timestamp_ns()));
+  aos::realtime_clock::time_point frame_timestamp(
+      std::chrono::nanoseconds(frame.realtime_timestamp_ns()));
 
   std::chrono::duration<double> time(frame_timestamp -
-                                     first_frame_monotonic_.value());
+                                     first_frame_realtime_.value());
 
   // TODO: maybe this should not be hardcoded
   const int device_id = 1;

frc971/can_logger/asc_logger.h

diff --git a/frc971/can_logger/asc_logger.h b/frc971/can_logger/asc_logger.h
index 2be2eb2..e7d4e74 100644
--- a/frc971/can_logger/asc_logger.h
+++ b/frc971/can_logger/asc_logger.h
@@ -25,7 +25,7 @@
   static void WriteHeader(std::ostream &file,
                           aos::realtime_clock::time_point start_time);
 
-  std::optional<aos::monotonic_clock::time_point> first_frame_monotonic_;
+  std::optional<aos::realtime_clock::time_point> first_frame_realtime_;
 
   std::ofstream output_;
 

frc971/can_logger/can_logger.cc

diff --git a/frc971/can_logger/can_logger.cc b/frc971/can_logger/can_logger.cc
index cfc3dd8..7d33464 100644
--- a/frc971/can_logger/can_logger.cc
+++ b/frc971/can_logger/can_logger.cc
@@ -75,8 +75,8 @@
   can_frame_builder.add_can_id(frame.can_id);
   can_frame_builder.add_flags(frame.flags);
   can_frame_builder.add_data(frame_data);
-  can_frame_builder.add_monotonic_timestamp_ns(
-      static_cast<std::chrono::nanoseconds>(
+  can_frame_builder.add_realtime_timestamp_ns(
+      std::chrono::duration_cast<std::chrono::nanoseconds>(
           std::chrono::seconds(tv.tv_sec) +
           std::chrono::microseconds(tv.tv_usec))
           .count());

frc971/can_logger/can_logging.fbs

diff --git a/frc971/can_logger/can_logging.fbs b/frc971/can_logger/can_logging.fbs
index ba60241..c7a82f2 100644
--- a/frc971/can_logger/can_logging.fbs
+++ b/frc971/can_logger/can_logging.fbs
@@ -7,7 +7,7 @@
   // The body of the CAN frame up to 64 bytes long.
   data:[ubyte] (id: 1);
   // The hardware timestamp of when the frame came in
-  monotonic_timestamp_ns:uint64 (id: 2);
+  realtime_timestamp_ns:uint64 (id: 2);
   // Additional flags for CAN FD
   flags: ubyte (id: 3);
 }