fix #24 improve precision (#26)

RobTillaart · Jul 12, 2021 · 11292be · 11292be
1 parent c0c6090
commit 11292be
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Showing 5 changed files with 16 additions and 11 deletions.
diff --git a/GY521.cpp b/GY521.cpp
@@ -1,7 +1,7 @@
 //
 //    FILE: GY521.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.3
+// VERSION: 0.3.4
 // PURPOSE: Arduino library for I2C GY521 accelerometer-gyroscope sensor
 //     URL: https://github.com/RobTillaart/GY521
 //
@@ -21,6 +21,7 @@
 //  0.3.1   2021-06-13  added more unit test + some initialization
 //  0.3.2   2021-07-05  fix #20 support multiWire
 //  0.3.3   2021-07-05  fix #22 improve maths
+//  0.3.4   2021-07-12  fix #24 improve precision
 
 
 #include "GY521.h"
@@ -93,14 +94,16 @@ bool GY521::wakeup()
 
 int16_t GY521::read()
 {
+  uint32_t now = millis();
   if (_throttle)
   {
-    if ((millis() - _lastTime) < _throttleTime)
+    if ((now - _lastTime) < _throttleTime)
     {
       // not an error.
       return GY521_THROTTLED;
     }
   }
+  _lastTime = now;
 
   // Connected ?
   _wire->beginTransmission(_address);
@@ -129,10 +132,11 @@ int16_t GY521::read()
   _gy = _WireRead2();  // GYRO_YOUT_H   GYRO_YOUT_L
   _gz = _WireRead2();  // GYRO_ZOUT_H   GYRO_ZOUT_L
 
-  // time interval
-  uint32_t now = millis();
-  float duration = (now - _lastTime) * 0.001;   // time in seconds.
-  _lastTime = now;
+  // duration interval
+  now = micros();
+  float duration = (now - _lastMicros) * 1e-6;  // duration in seconds.
+  _lastMicros = now;
+
 
   // next lines might be merged per axis.
 

diff --git a/GY521.h b/GY521.h
@@ -2,7 +2,7 @@
 //
 //    FILE: GY521.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.3
+// VERSION: 0.3.4
 // PURPOSE: Arduino library for I2C GY521 accelerometer-gyroscope sensor
 //     URL: https://github.com/RobTillaart/GY521
 //
@@ -15,7 +15,7 @@
 #include "Wire.h"
 
 
-#define GY521_LIB_VERSION           (F("0.3.3"))
+#define GY521_LIB_VERSION           (F("0.3.4"))
 
 
 #ifndef GY521_THROTTLE_TIME
@@ -104,6 +104,7 @@ class GY521
   bool     _throttle = true;        // to prevent reading too fast
   uint16_t _throttleTime = GY521_THROTTLE_TIME;
   uint32_t _lastTime = 0;           // to measure duration for math & throttle
+  uint32_t _lastMicros = 0;         // to measure duration for math & throttle
   int16_t  _error = GY521_OK;       // initially everything is OK
 
   uint8_t  _afs = 0;                // sensitivity factor

diff --git a/GY521_registers.h b/GY521_registers.h
@@ -1,7 +1,7 @@
 //
 //    FILE: GY521_registers.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.3
+// VERSION: see GY521.cpp
 // PURPOSE: Arduino library for I2C GY521 accelerometer-gyroscope sensor
 //     URL: https://github.com/RobTillaart/GY521
 //

diff --git a/library.json b/library.json
@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/GY521.git"
   },
-  "version": "0.3.3",
+  "version": "0.3.4",
   "license": "MIT",
   "frameworks": "arduino",
   "platforms": "*"

diff --git a/library.properties b/library.properties
@@ -1,5 +1,5 @@
 name=GY521
-version=0.3.3
+version=0.3.4
 author=Rob Tillaart <[email protected]>
 maintainer=Rob Tillaart <[email protected]>
 sentence=Arduino library for GY521 angle measurement