[examples] Fix memory over-allocation in Apriltag examples (#6517)

Change hamming distance to 1, add comment about memory usage.
wpilibsuite · Apr 22, 2024 · f26adc5 · f26adc5
1 parent 3c14d87
commit f26adc5
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Showing 2 changed files with 9 additions and 4 deletions.
diff --git a/wpilibcExamples/src/main/cpp/examples/AprilTagsVision/cpp/Robot.cpp b/wpilibcExamples/src/main/cpp/examples/AprilTagsVision/cpp/Robot.cpp
@@ -37,8 +37,11 @@ class Robot : public frc::TimedRobot {
  private:
   static void VisionThread() {
     frc::AprilTagDetector detector;
-    // look for tag36h11, correct 3 error bits
-    detector.AddFamily("tag36h11", 3);
+    // look for tag36h11, correct 1 error bit
+    // hamming 1 allocates 781KB, 2 allocates 27.4 MB, 3 allocates 932 MB
+    // max of 1 recommended for RoboRIO 1, while hamming 2 is feasible on the
+    // RoboRIO 2
+    detector.AddFamily("tag36h11", 1);
 
     // Set up Pose Estimator - parameters are for a Microsoft Lifecam HD-3000
     // (https://www.chiefdelphi.com/t/wpilib-apriltagdetector-sample-code/421411/21)

diff --git a/wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/apriltagsvision/Robot.java b/wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/apriltagsvision/Robot.java
@@ -39,8 +39,10 @@ public void robotInit() {
 
   void apriltagVisionThreadProc() {
     var detector = new AprilTagDetector();
-    // look for tag36h11, correct 3 error bits
-    detector.addFamily("tag36h11", 3);
+    // look for tag36h11, correct 1 error bit (hamming distance 1)
+    // hamming 1 allocates 781KB, 2 allocates 27.4 MB, 3 allocates 932 MB
+    // max of 1 recommended for RoboRIO 1, while hamming 2 is feasible on the RoboRIO 2
+    detector.addFamily("tag36h11", 1);
 
     // Set up Pose Estimator - parameters are for a Microsoft Lifecam HD-3000
     // (https://www.chiefdelphi.com/t/wpilib-apriltagdetector-sample-code/421411/21)