Diff: main.cpp

Revision:

4:14d1b87cd3c4

Parent:

3:a580414c44ce

Child:

5:2f708191f1bd

diff -r a580414c44ce -r 14d1b87cd3c4 main.cpp
--- a/main.cpp	Tue Aug 22 14:09:19 2017 +0000
+++ b/main.cpp	Tue Aug 22 21:51:07 2017 +0000
@@ -25,11 +25,10 @@
     InterruptIn op_sensor_int(P3_2);            // Config P3_2 as int. in for
     op_sensor_int.fall(&op_sensor_callback);    // FIFO ready interrupt
     
-    I2C i2cBus(I2C1_SDA, I2C1_SCL);     // I2C bus, P3_4 = SDA, P3_5 = SCL 
+    I2C i2cBus(I2C1_SDA, I2C1_SCL);         // I2C bus, P3_4 = SDA, P3_5 = SCL 
 
-    MAX30101 * op_sensor;
-    op_sensor = new MAX30101(i2cBus);
-    int rc = op_sensor_config(*op_sensor);
+    MAX30101 op_sensor(i2cBus);             // Create new MAX30101 on i2cBus
+    int rc = op_sensor_config(op_sensor);   // Config sensor, return 0 on success
     
     MAX30101::InterruptBitField_u ints;
     uint8_t fifoData[MAX30101::MAX_FIFO_BYTES];
@@ -39,23 +38,31 @@
     while(1) {
 
         if( rc == 0 ) {
-
+            
+            // Check if op_sensor interrupt asserted
             if(op_sensorIntFlag) {
+                
                 pc.printf("Interrupt seen...\r\n");
                 op_sensorIntFlag = 0;                       // Lower interrupt flag
-                rc = op_sensor->getInterruptStatus(ints);   // Read interrupt status 
+                rc = op_sensor.getInterruptStatus(ints);    // Read interrupt status 
                 
+                // Check if FIFO almost full interrupt asserted
                 if((rc == 0) && (ints.bits.a_full)) {
-                    rc = op_sensor->readFIFO(MAX30101::OneLedChannel, fifoData, readBytes);     // Read FIFO 
+                    
+                    // Read FIFO 
+                    rc = op_sensor.readFIFO(MAX30101::OneLedChannel, fifoData, readBytes);     
                     
                     if(rc == 0) {
+                        
                         pc.printf("FIFO Read, received %d samples\r\n\r\n", readBytes/3);
                         
+                        // Convert read bytes into samples
                         for(idx = 0; idx < readBytes; idx+=3) {
                             sample = (fifoData[idx]<<16) | (fifoData[idx+1]<<8) | (fifoData[idx+2]);
-                            opSample = sample >> 8;
+                            opSample = sample >> 8;                         // Sign extends sample to 16-bit opSample
                             pc.printf("Op. Sample : %i\r\n", opSample);     // Print results
                         }
+                        
                         pc.printf("\r\n\r\n");
                         
                     }
@@ -64,7 +71,8 @@
         
         } else {        
             
-            pc.printf("Something went wrong, check the I2C bus or power connections... \r\n");
+            pc.printf("Something went wrong, "
+                      "check the I2C bus or power connections... \r\n");
             bLed = LED_OFF;
             gLed = LED_OFF;
             
@@ -104,7 +112,7 @@
     {
         fifoConfig.all = 0;
         fifoConfig.bits.fifo_a_full = 15; // Max level of 15 samples 
-        fifoConfig.bits.sample_average = MAX30101::AveragedSamples_8; // Average 4 samples
+        fifoConfig.bits.sample_average = MAX30101::AveragedSamples_8; // Average 8 samples
         rc = op_sensor.setFIFOConfiguration(fifoConfig);
     }