Fix #51, #52, Add LowPass Filter functions (#53)

- fix #52, add **uint8_t getAddrress()**
- fix #51, add **bool setDLPFMode(uint8_t mode)** and **uint8_t getDLPFMode()**
- add const float GRAVITY=9.80655;
- minor edits

Author: RobTillaart

CHANGELOG.md

@@ -6,6 +6,13 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.5.3] - 2024-05-08
+- fix #52, add **uint8_t getAddrress()**
+- fix #51, add **bool setDLPFMode(uint8_t mode)** and **uint8_t getDLPFMode()**
+- add const float GRAVITY=9.80655;
+- minor edits
+
+
 ## [0.5.2] - 2024-01-16
 - fix #48, use float variables in example GY521_test_1.ino
 - add **void calibrate(uint16_t times)** to API
@@ -17,7 +24,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   - add some tables
 - minor edits in examples
 
-
 ## [0.5.1] - 2023-12-11
 - redo initialization order.
 

GY521.cpp

@@ -1,7 +1,7 @@
 //
 //    FILE: GY521.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.5.2
+// VERSION: 0.5.3
 // PURPOSE: Arduino library for I2C GY521 accelerometer-gyroscope sensor
 //     URL: https://github.com/RobTillaart/GY521
 
@@ -53,6 +53,12 @@ bool GY521::isConnected()
 }
 
 
+uint8_t GY521::getAddress()
+{
+  return _address;
+}
+
+
 void GY521::reset()
 {
   setThrottleTime(GY521_THROTTLE_TIME);
@@ -71,7 +77,7 @@ void GY521::calibrate(uint16_t times)
   //  disable throttling / caching of read values.
   bool oldThrottle = _throttle;
   _throttle = false;
-  
+
   //  set errors to zero
   axe = aye = aze = 0;
   gxe = gye = gze = 0;
@@ -476,6 +482,30 @@ uint8_t GY521::getGyroSensitivity()
 }
 
 
+//  CONFIGURATION
+//  Digital Low Pass Filter  datasheet P13-reg26
+bool GY521::setDLPFMode(uint8_t mode)
+{
+  if (mode > 6)
+  {
+    _error = GY521_ERROR_PARAMETER;
+    return false;
+  }
+  uint8_t value = getRegister(GY521_CONFIG);
+  value &= 0xF8;
+  value |= mode;
+  return (setRegister(GY521_CONFIG, value) == GY521_OK);
+}
+
+
+uint8_t GY521::getDLPFMode()
+{
+  uint8_t val = getRegister(GY521_CONFIG);
+  return val & 0x07;
+}
+
+
+//  GENERIC
 uint8_t GY521::setRegister(uint8_t reg, uint8_t value)
 {
   _wire->beginTransmission(_address);

GY521.h

@@ -2,7 +2,7 @@
 //
 //    FILE: GY521.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.5.2
+// VERSION: 0.5.3
 // PURPOSE: Arduino library for I2C GY521 accelerometer-gyroscope sensor
 //     URL: https://github.com/RobTillaart/GY521
 
@@ -11,7 +11,9 @@
 #include "Wire.h"
 
 
-#define GY521_LIB_VERSION           (F("0.5.2"))
+#define GY521_LIB_VERSION           (F("0.5.3"))
+
+const float GRAVITY = 9.80655;
 
 
 //  THROTTLE TIMING
@@ -26,6 +28,7 @@
 #define GY521_ERROR_READ            -1
 #define GY521_ERROR_WRITE           -2
 #define GY521_ERROR_NOT_CONNECTED   -3
+#define GY521_ERROR_PARAMETER       -4
 
 
 //  CONVERSION CONSTANTS
@@ -42,6 +45,7 @@ class GY521
 
   bool     begin();
   bool     isConnected();
+  uint8_t  getAddress();
   void     reset();
 
   //  EXPERIMENTAL
@@ -105,6 +109,10 @@ class GY521
   //  last time sensor is actually read.
   uint32_t lastTime()    { return _lastTime; };
 
+  //  CONFIGURATION
+  //  Digital Low Pass Filter - datasheet P13-reg26
+  bool     setDLPFMode(uint8_t mode);  //  returns false if mode > 6
+  uint8_t  getDLPFMode();
 
   //  generic worker to get access to all functionality
   uint8_t  setRegister(uint8_t reg, uint8_t value);

README.md

@@ -56,7 +56,6 @@ for analysis e.g. in a spreadsheet.
 - https://github.com/RobTillaart/AngleConverter
 
 
-
 ## Breakout board
 
 From left to right
@@ -142,8 +141,8 @@ Drawback is that this would make the duration unpredictable.
 - **uint8_t getAccelSensitivity()** returns 0, 1, 2, 3
 - **bool setGyroSensitivity(uint8_t gs)** gs = 0,1,2,3  ==>  250, 500, 1000, 2000 degrees/second
 - **uint8_t getGyroSensitivity()** returns 0, 1, 2, 3  
-= **void setNormalize(bool normalize = true)** normalizes pitch roll yaw or not. Default true.
-= **bool getNormalize()** returns flag.
+- **void setNormalize(bool normalize = true)** normalizes pitch roll yaw or not. Default true.
+- **bool getNormalize()** returns flag.
 
 
 #### Actual read
@@ -196,7 +195,25 @@ If **setNormalize(true)** return value will be 0-359.999
 If **setNormalize(true)** return value will be 0-359.999
 
 
-### Register access
+#### Digital Low Pass Filter
+
+See datasheet P13-reg26
+
+- **bool setDLPFMode(uint8_t mode)** mode = 0..6, returns false if mode > 6.
+- **uint8_t getDLPFMode()** returns the current (set) mode.
+
+| Mode | Acc bandwidth | delay  | Gyro bandwidth | delay  |   Fs  |
+|:----:|:-------------:|:------:|:--------------:|:------:|:-----:|
+|   0  |     260 Hz    |   0.0  |      256 Hz    |   1.0  | 8 kHz |
+|   1  |     184 Hz    |   2.0  |      188 Hz    |   1.9  | 1 kHz |
+|   2  |      94 Hz    |   3.0  |       98 Hz    |   2.8  | 1 kHz |
+|   3  |      44 Hz    |   4.9  |       42 Hz    |   4.8  | 1 kHz |
+|   4  |      21 Hz    |   8.5  |       20 Hz    |   8.3  | 1 kHz |
+|   5  |      10 Hz    |  13.8  |       10 Hz    |  13.4  | 1 kHz |
+|   6  |       5 Hz    |  19.0  |        5 Hz    |  18.6  | 1 kHz |
+
+
+#### Generic Register Access
 
 Read the register PDF for the specific value and meaning of registers.
 
@@ -222,26 +239,31 @@ Read the register PDF for the specific value and meaning of registers.
 
 #### Sensitivity Acceleration
 
-unit g = gravity == 9.81 m/s^2
+The strength of Earth's gravity varies with latitude (equator = 0°, poles = 90°).
+The standard value for gravity (gn) is 9.80665 m/s^2 (often 9.81 m/s^2)
+At the equator the gravity (ge) is 9.78033 m/s^2.
+
+The library provides the constant GRAVITY = 9.80655
 
-| Acceleration  |  value  |  notes  |
-|:--------------|:-------:|:-------:|
-|      2 g      |    0    |  default
-|      4 g      |    1    |
-|      8 g      |    2    |
-|     16 g      |    3    |
+
+|  value  | Acceleration  |    m/s2    |  notes  |
+|:-------:|:--------------|:----------:|:-------:|
+|    0    |      2 g      |   19.6131  |  default
+|    1    |      4 g      |   39.2262  |
+|    2    |      8 g      |   78.4524  |
+|    3    |     16 g      |  156.9048  |
 
 
 #### Sensitivity Gyroscope
 
 unit dps = degrees per second.
 
-|  Gyroscope    |  value  |  notes  |
-|:--------------|:-------:|:-------:|
-|   250 dps     |    0    |  default
-|   500 dps     |    1    |
-|  1000 dps     |    2    |
-|  2000 dps     |    3    |
+|  value  |  Gyroscope  |  radians/sec  |  notes  |
+|:-------:|:------------|:-------------:|:-------:|
+|    0    |   250 dps   |   4.36332313  |  default
+|    1    |   500 dps   |   8.72664626  |
+|    2    |  1000 dps   |  17.45329252  |
+|    3    |  2000 dps   |  34.90658504  |
 
 
 ## Operation
@@ -251,6 +273,9 @@ See examples, use with care.
 
 ## Future
 
+There is no intention to implement getters and setters for all registers.
+However if one specific is needed, please open an issue.
+
 #### Must
 
 - time

keywords.txt

@@ -8,6 +8,7 @@ GY521	KEYWORD1
 # Methods and Functions (KEYWORD2)
 begin	KEYWORD2
 isConnected	KEYWORD2
+getAddress	KEYWORD2
 reset	KEYWORD2
 wakeup	KEYWORD2
 
@@ -43,8 +44,13 @@ getRoll	KEYWORD2
 getYaw	KEYWORD2
 
 lastTime	KEYWORD2
+
+setDLPFMode	KEYWORD2
+getDLPFMode	KEYWORD2
+
 setRegister	KEYWORD2
 getRegister	KEYWORD2
+
 getError	KEYWORD2
 
 

library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/GY521.git"
   },
-  "version": "0.5.2",
+  "version": "0.5.3",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",

library.properties

@@ -1,5 +1,5 @@
 name=GY521
-version=0.5.2
+version=0.5.3
 author=Rob Tillaart <[email protected]>
 maintainer=Rob Tillaart <[email protected]>
 sentence=Arduino library for GY521 angle measurement