Heart Rate 4 Click Board

Code examples for the Heart Rate 4 Click Board™, written for MikroElektronika hardware and compilers are available on Libstock.

CODE SNIPPET

This code snippet initializes the system and display, initializes the board and sets I2C registers. New data from the sensor is collected in a endless loop, via polling and sent via UART to MikroPlot when we are in active heart rate mode.

01  void main( void )
02   {
03     system_init();
04     display_init();
05     hr4_init();
06     hr4_set_registers();
07 
08     TFT_Set_Font( &HandelGothic_BT21x22_Regular, CL_RED, FO_HORIZONTAL );
09     TFT_Write_Text( "Use MikroPlot Graph Generator", 10, 100 );
10     TFT_Set_Font( &HandelGothic_BT21x22_Regular, CL_BLUE, FO_HORIZONTAL );
11     TFT_Write_Text( "Place Finger On Sensor", 19, 170 );
12 
13     while ( true )
14     {
15       // Clearing the interrupt by reading the Interrupt Status 1
16       if ( hr4_is_new_fifo_data_ready() & 0x1 ) read_f = true;
17 
18       if ( read_f )                          // If INT was emitted
19       {
20          read_f = 0;
21 
22          if ( !start_f )                     // First start
23          {
24             start_f = true;
25             InitTimer1();                    // Initializing Timer 1
26             LOG("STARTrn");                // Sending START command to uPlot
27          }
28 
29          red_sample = hr4_read_red();        // Read RED sensor data
30 
31          LongToStr(miliseconds_counter , txt_milis);
32          LongToStr(red_sample , txt_val);
33          Ltrim(txt_val);
34          Ltrim(txt_milis);
35 
36          // If sample pulse amplitude is under threshold value ( proximity mode )
37          if ( red_sample > 0 && red_sample < 32000 )
38          {
39            stop_f = true;
40            if ( !no_finger_f )
41            {
42              TFT_Rectangle( 19, 170, 310, 200 );
43              TFT_Write_Text( "Place Finger On Sensor", 19, 170 );
44            }
45 
46            no_finger_f = true;
47          }
48 
49          // If finger is detected ( we are in active heart rate mode )
50          else if( red_sample != 0)
51          {
52              stop_f = false;
53 
54              if ( no_finger_f )
55              {
56               TFT_Rectangle( 19, 170, 310, 200 );
57               TFT_Write_Text( "Generating Graph...", 19, 170 );
58              }
59 
60              no_finger_f = false;
61 
62              // Sending data to MikroPlot in format:[pulse_value, milis] via UART
63              LOG(txt_val);
64              LOG(",");
65              LOG(txt_milis);
66              LOG("rn");
67          }
68       }
69     }
70   }