Update fifo_interrupt.ino

Simplified FIFO interrupt example, as proposed by @cparata

Co-Authored-By: Carlo Parata <[email protected]>

Author: alvaro-oliver

examples/fifo_interrupt.ino

@@ -37,37 +37,28 @@
 
 #include "LSM6DSOXSensor.h"
 
-#define SR 417 // Sample rate. Options are: 12.5, 26, 52, 104, 208, 417, 833, 1667, 3333 and 6667 Hz
-#define WTM_LV 500 // Watermark threshold level. Max samples in this FIFO configuration is 512 (accel and gyro only).
+#define SR 417.0f // Sample rate. Options are: 12.5, 26, 52, 104, 208, 417, 833, 1667, 3333 and 6667 Hz
+#define WTM_LV 102 // Watermark threshold level. Max samples in this FIFO configuration is 512 (accel and gyro only).
 
-// Define interrupt pins acording to MCU board and sensor wiring.
+// Define interrupt pins according to MCU board and sensor wiring.
 #define INT1_pin A0 // MCU input pin connected to sensor INT1 output pin
-#define INT2_pin A1 // MCU imput pin connected to sensor INT2 output pin
 
 /** LSM6DSOX i2c address:
  * LSM6DSOX_I2C_ADD_L: 0x6A (default)
  * LSM6DSOX_I2C_ADD_H: 0x6B 
  **/
 LSM6DSOXSensor lsm6dsoxSensor = LSM6DSOXSensor(&Wire, LSM6DSOX_I2C_ADD_L);
 
-volatile uint8_t wtmFlag = 0; // FIFO watermark flag
 volatile uint8_t fullFlag = 0; // FIFO full flag
 
 // ISR callback for INT1
-void INT1_wtmEvent_cb() {
-
-  wtmFlag = 1;
-}
-
-// ISR callback for INT2
-void INT2_fullEvent_cb() {
-
+void INT1_fullEvent_cb() {
   fullFlag = 1;
 }
 
 void setup() {
 
-  Serial.begin(115200);
+  Serial.begin(921600);
   // Comment this line to skip waiting for serial:
   while(!Serial) delay(10);
 
@@ -76,10 +67,8 @@ void setup() {
   Wire.setClock(400000);
 
   // Interrupt pin settings
-  pinMode(INT1_pin, INPUT_PULLUP);
-  pinMode(INT2_pin, INPUT_PULLUP);
-  attachInterrupt(digitalPinToInterrupt(INT1_pin), INT1_wtmEvent_cb, RISING); // attach watermark event to INT1 input pin
-  attachInterrupt(digitalPinToInterrupt(INT2_pin), INT2_fullEvent_cb, RISING); // attach full event to INT2 input pin
+  pinMode(INT1_pin, INPUT);
+  attachInterrupt(digitalPinToInterrupt(INT1_pin), INT1_fullEvent_cb, RISING); // attach watermark event to INT1 input pin
 
   // Initialize sensors
   lsm6dsoxSensor.begin();
@@ -122,16 +111,17 @@ void setup() {
    * LSM6DSOX_BYPASS_TO_STREAM_MODE: FIFO buffer starts operating in Bypass mode and switches to Continuous mode when an event condition occurs.
    * */
   lsm6dsoxSensor.Set_FIFO_Mode(LSM6DSOX_BYPASS_MODE); // flush any previous value in FIFO before start
-  lsm6dsoxSensor.Set_FIFO_Mode(LSM6DSOX_STREAM_MODE); // start batching in continous mode
-  
+
+  lsm6dsoxSensor.Set_FIFO_INT1_FIFO_Full(1); // enable FIFO full interrupt on sensor INT1 pin
+
   // Set FIFO watermark level. Can be used to check when the number of samples in buffer reaches this defined threshold level.
   lsm6dsoxSensor.Set_FIFO_Watermark_Level(WTM_LV);
 
   // FIFO size can be limited to the watermark level by setting the STOP_ON_WTM flag to 1
-  //lsm6dsoxSensor.Set_FIFO_Stop_On_Fth(1);
+  lsm6dsoxSensor.Set_FIFO_Stop_On_Fth(1);
 
-  lsm6dsoxSensor.Set_FIFO_INT1_FIFO_Threshold(1); // enable FIFO threshold interrupt on sensor INT1 pin
-  lsm6dsoxSensor.Set_FIFO_INT2_FIFO_Full(1); // enable FIFO full interrupt on sensor INT2 pin
+  // start batching in continous mode
+  lsm6dsoxSensor.Set_FIFO_Mode(LSM6DSOX_STREAM_MODE);
 
   Serial.println("Starting...");
 }
@@ -142,55 +132,72 @@ void loop() {
   uint8_t Tag; // FIFO data sensor identifier
   int32_t acceleration[3]; // X, Y, Z accelerometer values in mg
   int32_t rotation[3]; // X, Y, Z giroscope values in mdps
+  int16_t dummy[3];
+  uint8_t fullStatus = 0; // full status
+  int32_t count_acc_samples = 0;
+  int32_t count_gyro_samples = 0;
+  int32_t count_dummy_samples = 0;
 
   // Get number of samples in buffer
   lsm6dsoxSensor.Get_FIFO_Num_Samples(&numSamples);
-  Serial.print("Samples in FIFO: "); Serial.println(numSamples);
+  Serial.print("Samples in FIFO: ");
+  Serial.println(numSamples);
 
   // Check if FIFO threshold level was reached.
-  if (wtmFlag != 0) {
-    Serial.println("-- FIFO Watermark level reached!, fetching data.");
+  if (fullFlag != 0) {
+    fullFlag = 0;
+
+    lsm6dsoxSensor.Get_FIFO_Full_Status(&fullStatus);
+
+    if(fullStatus) {
+      Serial.println("-- FIFO Watermark level reached!, fetching data.");
 
-    // fetch data from FIFO
-    for (uint16_t i = 0; i < WTM_LV; i++) {
+      lsm6dsoxSensor.Get_FIFO_Num_Samples(&numSamples);
+
+      Serial.print("numSamples=");
+      Serial.println(numSamples);
+
+      // fetch data from FIFO
+      for (uint16_t i = 0; i < numSamples; i++) {
 
-      lsm6dsoxSensor.Get_FIFO_Tag(&Tag); // get data identifier
+        lsm6dsoxSensor.Get_FIFO_Tag(&Tag); // get data identifier
 
-      // Get gyroscope data
-      if (Tag == 1) { 
-        lsm6dsoxSensor.Get_FIFO_G_Axes(rotation);
-        #if 0 // set to 1 for printing values
-        Serial.print("mdps: "); Serial.print(rotation[0]); 
-        Serial.print(", "); Serial.print(rotation[1]); 
-        Serial.print(", "); Serial.print(rotation[2]); 
-        Serial.println();
-        #endif
-      } 
+        // Get gyroscope data
+        if (Tag == 1) { 
+          lsm6dsoxSensor.Get_FIFO_G_Axes(rotation);
+          count_gyro_samples++;
+          #if 1 // set to 1 for printing values
+          Serial.print("mdps: "); Serial.print(rotation[0]); 
+          Serial.print(", "); Serial.print(rotation[1]); 
+          Serial.print(", "); Serial.print(rotation[2]); 
+          Serial.println();
+          #endif
+        } 
 
-      // Get accelerometer data
-      else if (Tag == 2) {
-        lsm6dsoxSensor.Get_FIFO_X_Axes(acceleration); 
-        #if 0 // set to 1 for printing values
-        Serial.print("mG: "); Serial.print(acceleration[0]); 
-        Serial.print(", "); Serial.print(acceleration[1]); 
-        Serial.print(", "); Serial.print(acceleration[2]); 
-        Serial.println();
-        #endif
+        // Get accelerometer data
+        else if (Tag == 2) {
+          lsm6dsoxSensor.Get_FIFO_X_Axes(acceleration);
+          count_acc_samples++; 
+          #if 1 // set to 1 for printing values
+          Serial.print("mG: "); Serial.print(acceleration[0]); 
+          Serial.print(", "); Serial.print(acceleration[1]); 
+          Serial.print(", "); Serial.print(acceleration[2]); 
+          Serial.println();
+          #endif
+        }
+
+        // Flush unused tag
+        else {
+          lsm6dsoxSensor.Get_FIFO_Data((uint8_t *)dummy);
+          count_dummy_samples++;
+        }
       }
+      Serial.print("Acc Samples: ");
+      Serial.println(count_acc_samples);
+      Serial.print("Gyro Samples: ");
+      Serial.println(count_gyro_samples);
+      Serial.print("Dummy Samples: ");
+      Serial.println(count_dummy_samples);
     }
-
-    wtmFlag = 0;
   }
-
-  // Check if FIFO is full.
-  if (fullFlag != 0) {
-    Serial.println("-- FIFO is full!, consider reducing Watermark Level or Buffer Data Rate.\nFlushing data from FIFO.");
-    lsm6dsoxSensor.Set_FIFO_Mode(LSM6DSOX_BYPASS_MODE); // flush FIFO data
-    lsm6dsoxSensor.Set_FIFO_Mode(LSM6DSOX_STREAM_MODE); // continue batching
-
-    fullFlag = 0;
-  }
-
-  delay(10); // FIFO continues batching while we sleep
-
-}
+}