Add tare function and example

Author: s-reynier

examples/Example22-TareManufacturingCalibration/Example22-TareManufacturingCalibration.ino

@@ -0,0 +1,110 @@
+/*
+  Using the BNO080 IMU
+  By: Nathan Seidle
+  SparkFun Electronics
+  Date: December 21st, 2017
+  SparkFun code, firmware, and software is released under the MIT License.
+	Please see LICENSE.md for further details.
+
+  Feel like supporting our work? Buy a board from SparkFun!
+  https://www.sparkfun.com/products/14586
+
+  This example shows how to output the i/j/k/real parts of the rotation vector.
+  https://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation
+
+  It takes about 1ms at 400kHz I2C to read a record from the sensor, but we are polling the sensor continually
+  between updates from the sensor. Use the interrupt pin on the BNO080 breakout to avoid polling.
+
+  Hardware Connections:
+  Attach the Qwiic Shield to your Arduino/Photon/ESP32 or other
+  Plug the sensor onto the shield
+  Serial.print it out at 9600 baud to serial monitor.
+*/
+
+#include <Wire.h>
+
+#include "SparkFun_BNO080_Arduino_Library.h" // Click here to get the library: http://librarymanager/All#SparkFun_BNO080
+BNO080 myIMU;
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.println();
+  Serial.println("BNO080 Read Example");
+
+  Wire.begin();
+
+  //Are you using a ESP? Check this issue for more information: https://github.com/sparkfun/SparkFun_BNO080_Arduino_Library/issues/16
+//  //=================================
+//  delay(100); //  Wait for BNO to boot
+//  // Start i2c and BNO080
+//  Wire.flush();   // Reset I2C
+//  IMU.begin(BNO080_DEFAULT_ADDRESS, Wire);
+//  Wire.begin(4, 5);
+//  Wire.setClockStretchLimit(4000);
+//  //=================================
+
+  if (myIMU.begin() == false)
+  {
+    Serial.println("BNO080 not detected at default I2C address. Check your jumpers and the hookup guide. Freezing...");
+    while (1);
+  }
+
+  Wire.setClock(400000); //Increase I2C data rate to 400kHz
+
+  myIMU.enableRotationVector(50); //Send data update every 50ms
+
+  Serial.println(F("Rotation vector enabled"));
+  Serial.println(F("Output in form i, j, k, real, accuracy"));
+}
+
+void loop()
+{
+  if(Serial.available())
+  {
+  byte incoming = Serial.read();
+
+  if(incoming == 't')
+  {
+    myIMU.tareAllAxes(); //tare x,y,z axes to calibrate device with default manufacturing
+    myIMU.saveTare(); //save tare
+    delay(1);
+    }
+  }
+  
+  //Look for reports from the IMU
+  if (myIMU.dataAvailable() == true)
+  {
+    float quatI = myIMU.getQuatI();
+    float quatJ = myIMU.getQuatJ();
+    float quatK = myIMU.getQuatK();
+    float quatReal = myIMU.getQuatReal();
+    float quatRadianAccuracy = myIMU.getQuatRadianAccuracy();
+
+   /* See page 5 of Tare 
+    * Determine North in your current environment
+    * a. You can either look at a physical compass, or look at the Rotation Vector to
+    * determine where North is. 
+    * When the Rotation Vector reads W=1, X=0, Y=0, Z=0 the device is pointed North
+
+    *    w = real
+    *     x = i
+    *     y = j
+    *     z = k
+    */
+
+    Serial.print(F(", W : "));
+    Serial.print(quatReal, 2);
+    Serial.print(F(", x : "));
+    Serial.print(quatI, 2);
+    Serial.print(F(", y: "));
+    Serial.print(quatJ, 2);
+    Serial.print(F(", z: "));
+    Serial.print(quatK, 2);
+    Serial.print(F(","));
+    Serial.print(quatRadianAccuracy, 2);
+    Serial.print(F(","));
+
+    Serial.println();
+  }
+}

src/SparkFun_BNO080_Arduino_Library.cpp

@@ -1221,6 +1221,53 @@ boolean BNO080::calibrationComplete()
 	return (false);
 }
 
+
+//See Tare Procedure Tare Function Usage Guide
+//https://www.ceva-dsp.com/wp-content/uploads/2019/09/BNO080-BNO085-Tare-Function-Usage-Guide.pdf
+void BNO080::tareAllAxes()
+{
+	/*shtpData[3] = 0; //P0 - P0 (Subcommand)
+	shtpData[4] = 0; //P1 - All 3 Axes(x,y,z)
+	shtpData[5] = 0; //P2 - Rotation vector
+	shtpData[6] = 0; //P3 - Reserved
+	shtpData[7] = 0; //P4 - Reserved
+	shtpData[8] = 0; //P5 - Reserved
+	shtpData[9] = 0; //P6 - Reserved
+	shtpData[10] = 0; //P7 - Reserved
+	shtpData[11] = 0; //P8 - Reserved*/
+
+	for (uint8_t x = 3; x < 12; x++) //Clear this section of the shtpData array
+		shtpData[x] = 0;
+	
+	shtpData[4] = 0x07;
+
+	//Using this shtpData packet, send a command
+	sendCommand(COMMAND_TARE); //Save TARE command
+}
+
+//See Tare Procedure Tare Function Usage Guide
+//Run the Persist Tare
+//https://www.ceva-dsp.com/wp-content/uploads/2019/09/BNO080-BNO085-Tare-Function-Usage-Guide.pdf
+void BNO080::saveTare()
+{
+	/*shtpData[3] = 0; //P0 (Subcommand)
+	shtpData[4] = 0; //Reserved
+	shtpData[5] = 0; //Reserved
+	shtpData[6] = 0; //P3 - Reserved
+	shtpData[7] = 0; //P4 - Reserved
+	shtpData[8] = 0; //P5 - Reserved
+	shtpData[9] = 0; //P6 - Reserved
+	shtpData[10] = 0; //P7 - Reserved
+	shtpData[11] = 0; //P8 - Reserved*/
+	
+	for (uint8_t x = 3; x < 12; x++) //Clear this section of the shtpData array
+		shtpData[x] = 0;
+	
+	shtpData[3] = 0x01;
+	
+	sendCommand(COMMAND_TARE); //Run TARE command
+}
+
 //Given a sensor's report ID, this tells the BNO080 to begin reporting the values
 void BNO080::setFeatureCommand(uint8_t reportID, uint16_t timeBetweenReports)
 {

src/SparkFun_BNO080_Arduino_Library.h

@@ -240,6 +240,9 @@ class BNO080
 	float getPitch();
 	float getYaw();
 
+	void BNO080::tareAllAxes();
+	void BNO080::saveTare();
+
 	void setFeatureCommand(uint8_t reportID, uint16_t timeBetweenReports);
 	void setFeatureCommand(uint8_t reportID, uint16_t timeBetweenReports, uint32_t specificConfig);
 	void sendCommand(uint8_t command);