Merge pull request #10 from RobTillaart/develop

0.2.0 improve error handling

GY521.cpp

@@ -1,7 +1,7 @@
 //
 //    FILE: GY521.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.5
+// VERSION: 0.2.0
 // PURPOSE: Arduino library for I2C GY521 accelerometer-gyroscope sensor
 //     URL: https://github.com/RobTillaart/GY521
 //
@@ -12,6 +12,7 @@
 // 0.1.3    2020-08-07 fix ESP support + pitch roll yaw demo
 // 0.1.4    2020-09-29 fix #5 missing ;
 // 0.1.5    2020-09-29 fix #6 fix math for Teensy
+// 0.2.0    2020-11-03 improve error handling
 
 
 #include "GY521.h"
@@ -57,15 +58,15 @@ bool GY521::begin()
 bool GY521::isConnected()
 {
   Wire.beginTransmission(_address);
-  return Wire.endTransmission() == 0;
+  return (Wire.endTransmission() == 0);
 }
 
 bool GY521::wakeup()
 {
   Wire.beginTransmission(_address);
   Wire.write(GY521_PWR_MGMT_1);
   Wire.write(GY521_WAKEUP);
-  return Wire.endTransmission() == 0;
+  return (Wire.endTransmission() == 0);
 }
 
 int16_t GY521::read()
@@ -118,7 +119,7 @@ int16_t GY521::read()
   _aaz += aze;
 
   // Convert to Celsius
-  _temperature = (_temperature + 12412.0) * 0.00294117647;  //  == /340.0  + 36.53;
+  _temperature = _temperature * 0.00294117647 + 36.53;  //  == /340.0  + 36.53;
 
   // Convert raw Gyro to degrees/seconds
   _gx *= _raw2dps;
@@ -141,48 +142,72 @@ int16_t GY521::read()
   return GY521_OK;
 }
 
-void GY521::setAccelSensitivity(uint8_t as)
+bool GY521::setAccelSensitivity(uint8_t as)
 {
   _afs = as;
   if (_afs > 3) _afs = 3;
   uint8_t val = getRegister(GY521_ACCEL_CONFIG);
+  if (_error != 0)
+  {
+    return false;
+  }
   // no need to write same value
   if (((val >> 3) & 3) != _afs)
   {
     val &= 0xE7;
     val |= (_afs << 3);
-    setRegister(GY521_ACCEL_CONFIG, val);
+    if (setRegister(GY521_ACCEL_CONFIG, val) != GY521_OK)
+    {
+      return false;
+    }
   }
   // calculate conversion factor.
   _raw2g = (1 << _afs) / 16384.0;
+  return true;
 }
 
 uint8_t GY521::getAccelSensitivity()
 {
   uint8_t val = getRegister(GY521_ACCEL_CONFIG);
+  if (_error != GY521_OK)
+  {
+    return _error; // return and propagate error (best thing to do)
+  }
   _afs = (val >> 3) & 3;
   return _afs;
 }
 
-void  GY521::setGyroSensitivity(uint8_t gs)
+bool GY521::setGyroSensitivity(uint8_t gs)
 {
   _gfs = gs;
   if (_gfs > 3) _gfs = 3;
   uint8_t val = getRegister(GY521_GYRO_CONFIG);
+  if (_error != 0)
+  {
+    return false;
+  }
   // no need to write same value
   if (((val >> 3) & 3) != _gfs)
   {
     val &= 0xE7;
     val |= (_gfs << 3);
-    setRegister(GY521_GYRO_CONFIG, val);
+    if (setRegister(GY521_GYRO_CONFIG, val) != GY521_OK)
+    {
+      return false;
+    }
   }
   // calculate conversion factor.
   _raw2dps = (1 << _gfs) / 131.0;
+  return true;
 }
 
 uint8_t GY521::getGyroSensitivity()
 {
   uint8_t val = getRegister(GY521_GYRO_CONFIG);
+  if (_error != GY521_OK)
+  {
+    return _error; // return and propagate error (best thing to do)
+  }
   _gfs = (val >> 3) & 3;
   return _gfs;
 }
@@ -193,17 +218,29 @@ uint8_t GY521::setRegister(uint8_t reg, uint8_t value)
   Wire.write(reg);
   Wire.write(value);
   // no need to do anything if not connected.
-  if (Wire.endTransmission() != 0) return GY521_ERROR_WRITE;
+  if (Wire.endTransmission() != 0) 
+  {
+    _error = GY521_ERROR_WRITE;
+    return _error;
+  }
   return GY521_OK;
 }
 
 uint8_t GY521::getRegister(uint8_t reg)
 {
   Wire.beginTransmission(_address);
   Wire.write(reg);
-  if (Wire.endTransmission() != 0) return GY521_ERROR_WRITE;
+  if (Wire.endTransmission() != 0)
+  {
+    _error = GY521_ERROR_WRITE;
+    return _error;
+  }
   uint8_t n = Wire.requestFrom(_address, (uint8_t) 1);
-  if (n != 1) return GY521_ERROR_READ;
+  if (n != 1) 
+  {
+    _error = GY521_ERROR_READ;
+    return _error;
+  }
   uint8_t val = Wire.read();
   return val;
 }

GY521.h

@@ -2,7 +2,7 @@
 //
 //    FILE: GY521.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.5
+// VERSION: 0.2.0
 // PURPOSE: Arduino library for I2C GY521 accelerometer-gyroscope sensor
 //     URL: https://github.com/RobTillaart/GY521
 //
@@ -13,17 +13,18 @@
 #include "Arduino.h"
 #include "Wire.h"
 
-#define GY521_LIB_VERSION (F("0.1.5"))
+#define GY521_LIB_VERSION (F("0.2.0"))
 
 #ifndef GY521_THROTTLE_TIME
 #define GY521_THROTTLE_TIME     10   // milliseconds
 #endif
 
-// ERRORCODES getRaw()
-#define GY521_OK                0
-#define GY521_THROTTLED         1
-#define GY521_ERROR_READ       -1
-#define GY521_ERROR_WRITE      -2
+// ERROR CODES
+#define GY521_OK                     0
+#define GY521_THROTTLED              1
+#define GY521_ERROR_READ            -1
+#define GY521_ERROR_WRITE           -2
+#define GY521_ERROR_NOT_CONNECTED   -3
 
 
 class GY521
@@ -44,36 +45,41 @@ class GY521
   // 0..65535 millis == roughly 1 minute.
   void     setThrottleTime(uint16_t ti )     { _throttleTime = ti; };
   uint16_t getThrottleTime()                 { return _throttleTime; };
+
+  // returns GY521_OK or one of the error codes above.
   int16_t  read();
 
+  // SET BEFORE READ
   // as = 0,1,2,3 ==> 2g 4g 8g 16g
-  void     setAccelSensitivity(uint8_t as);
+  bool     setAccelSensitivity(uint8_t as);
   uint8_t  getAccelSensitivity();          // returns 0,1,2,3
+  // gs = 0,1,2,3  ==>  250, 500, 1000, 2000 degrees/second
+  bool     setGyroSensitivity(uint8_t gs);
+  uint8_t  getGyroSensitivity();           // returns 0,1,2,3  
+
+  // CALL AFTER READ
   float    getAccelX()   { return _ax; };
   float    getAccelY()   { return _ay; };
   float    getAccelZ()   { return _az; };
   float    getAngleX()   { return _aax; };
   float    getAngleY()   { return _aay; };
   float    getAngleZ()   { return _aaz; };
-
   float    getTemperature() { return _temperature; };
-
-  // gs = 0,1,2,3  ==>  250, 500, 1000, 2000 degrees/second
-  void     setGyroSensitivity(uint8_t gs);
-  uint8_t  getGyroSensitivity();           // returns 0,1,2,3
   float    getGyroX()    { return _gx; };
   float    getGyroY()    { return _gy; };
   float    getGyroZ()    { return _gz; };
-
   float    getPitch()    { return _pitch; };
   float    getRoll()     { return _roll; };
   float    getYaw()      { return _yaw; };
 
+  // last time sensor is actually read.
   uint32_t lastTime()    { return _lastTime; };
 
   // generic worker to get access to all functionality
   uint8_t  setRegister(uint8_t reg, uint8_t value);
   uint8_t  getRegister(uint8_t reg);
+  // get last error and reset error to OK.
+  int16_t  getError()    { return _error; _error = GY521_OK; };
 
   // callibration errors
   float    axe = 0, aye = 0, aze = 0;  // accelerometer errors
@@ -84,6 +90,7 @@ 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
+  int16_t  _error = GY521_OK;       // initially everything is OK
 
   uint8_t  _afs = 0;                // sensitivity factor
   float    _raw2g = 1.0/16384.0;    // raw data to gravity g's

keywords.txt

@@ -4,10 +4,14 @@
 GY521	KEYWORD1
 
 # Methods and Functions (KEYWORD2)
+begin	KEYWORD2
+isConnected	KEYWORD2
 wakeup	KEYWORD2
 read	KEYWORD2
 setThrottle	KEYWORD2
 getThrottle	KEYWORD2
+setThrottleTime	KEYWORD2
+getThrottleTime	KEYWORD2
 
 setAccelSensitivity	KEYWORD2
 getAccelSensitivity	KEYWORD2
@@ -31,11 +35,13 @@ getYaw	KEYWORD2
 lastTime	KEYWORD2
 setRegister	KEYWORD2
 getRegister	KEYWORD2
+getError	KEYWORD2
 
 # Constants (LITERAL1)
 GY521_LIB_VERSION	LITERAL1
 GY521_THROTTLE_TIME	LITERAL1
 GY521_OK	LITERAL1
 GY521_THROTTLED	LITERAL1
 GY521_ERROR_READ	LITERAL1
-GY521_ERROR_WRITE	LITERAL1
+GY521_ERROR_WRITE	LITERAL1
+GY521_ERROR_NOT_CONNECTED	LITERAL1

library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/GY521.git"
   },
-  "version":"0.1.5",
+  "version":"0.2.0",
   "frameworks": "arduino",
   "platforms": "*"
 }

library.properties

@@ -1,5 +1,5 @@
 name=GY521
-version=0.1.5
+version=0.2.0
 author=Rob Tillaart <[email protected]>
 maintainer=Rob Tillaart <[email protected]>
 sentence=Arduino library for GY521 angle measurement