Revision 8:208d965a3bd2, committed 2020-04-23

Comitter:

miguelangel_2511

Date:

Thu Apr 23 17:05:36 2020 +0000

Parent:

7:f4e248182d31

Child:

9:95fdcdc0977e

Commit message:

Se agrego la medicion y visualizacion grafica del volumen, el flujo y la presion. Sin embargo, aun no se han aplicado filtros a las seniales medidas.

Changed in this revision

--- a/main.cpp	Mon Apr 20 21:58:36 2020 +0000
+++ b/main.cpp	Thu Apr 23 17:05:36 2020 +0000
@@ -9,56 +9,35 @@
 #include "ventilator.h"
 
 
-// ******************************
-//      OBJECT CONSTRUCTION
-// ******************************
-
-Ticker ticker_int_10us; // Ticker interrupt
-
-
-// ******************************
-//      GLOBAL VARIABLES
-// ******************************
-
-
+int main(void) {
+    
+    System_Initialize();
 
-// ******************************
-//      FUNCTION DECLARATION
-// ******************************
-void Ticker_ISR(void); // ISR that is called when the timer reaches the set value
-
-
-int main(void) {
-    Buttons_Initialize();
-    ticker_int_10us.attach(&Ticker_ISR, 0.01);
-    Nextion_Interface_Initialize();
-    Pressure_Sensors_Initialize();
-    Stepper_Driver_Init();
-    
     while(1){     
          Stepper_Driver_State_Machine();
-         
          Nextion_Encoder_Interaction();
          
          if(read_pressure_sensors_flag){
              Pressure_Sensors_Read();
+             Calculate_Flow_From_Pressure();
+             Calculate_Volume_From_Flow();
              read_pressure_sensors_flag = 0;
          }
- /*        
+         
          if((stepper_driver_state != Stepper_Inspiration_Finish) && 
             (stepper_driver_state != Stepper_Expiration_Finish)){
+            /* Display sensed values if necessary */    
             if(pressure_sensor_display_update_flag){
-                Nextion_Update_Sensor_Values();
-                pressure_sensor_display_update_flag = 0;
+               Nextion_Update_Sensor_Values();
+               pressure_sensor_display_update_flag = 0;
             }
-            
+            /* Plot sensed values if necessary */
             if(pressure_sensor_waveform_update_flag){
                 Nextion_Update_Waveform_Values();
                 pressure_sensor_waveform_update_flag = 0;
-            }
+            }  
                  
-         }
- */        
+         }      
     }
   
     return 0;
@@ -66,21 +45,9 @@
 
 
 
-// Ticker Interrupt Service Routine
-void Ticker_ISR(void){
-   
-    static uint8_t conta_10ms = 0;
-    
-    Encoder_Read();
-    Button_Debounce();
-    
-    conta_10ms++;
-    
-    if(conta_10ms == 10){
-        conta_10ms = 0;
-        read_pressure_sensors_flag = 1;
-        pressure_sensor_display_update_flag = 1;
-        pressure_sensor_waveform_update_flag = 1;
-    }
-    
-}  
+  
+
+
+
+
+

--- a/nextion_interface.cpp	Mon Apr 20 21:58:36 2020 +0000
+++ b/nextion_interface.cpp	Thu Apr 23 17:05:36 2020 +0000
@@ -9,6 +9,7 @@
 #include "ventilator.h"
 
 
+
 /* Object definition */
 Serial  nextion_display(NEXTION_DISPLAY_TX_PIN,NEXTION_DISPLAY_RX_PIN);
 // For testing pusposes only
@@ -41,26 +42,39 @@
 
 void Nextion_Interface_Initialize(void){
     /* Configure baud rate */ 
+    nextion_display.baud(9600);
+    wait(1);
+    nextion_display.printf("baud=%d", NEXTION_DISPLAY_BAUD_RATE);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+    wait(1);
     nextion_display.baud(NEXTION_DISPLAY_BAUD_RATE);
-    //pc.baud(115200);
-    
-    //pc.printf("PUERTO SERIAL HABILITADO\n\n\r");
+    wait(1);
+
+    /* Draw separators for the displayed values */
+    nextion_display.printf("line 10,160,190,160,%d", WHITE);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+    nextion_display.printf("line 10,320,190,320,%d", WHITE);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+    nextion_display.printf("line 610,160,790,160,%d", WHITE);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+    nextion_display.printf("line 610,320,790,320,%d", WHITE);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);  
     
     /* Set font color */
-    nextion_display.printf("t6.pco=%d", NORMAL_COLOR);
+    nextion_display.printf("t1.pco=%d", NORMAL_COLOR);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff); 
+    nextion_display.printf("t4.pco=%d", NORMAL_COLOR);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
     nextion_display.printf("t7.pco=%d", NORMAL_COLOR);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-    nextion_display.printf("t8.pco=%d", NORMAL_COLOR);
-    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-    
-   // pc.printf("t6.pco=%d\n\r", NORMAL_COLOR);
-    //pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff); 
-   // pc.printf("t7.pco=%d\n\r", NORMAL_COLOR);
-   // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
-   // pc.printf("t8.pco=%d\n\r", NORMAL_COLOR);
-    //pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
-    
+  /*  
+    pc.printf("t6.pco=%d\n\r", NORMAL_COLOR);
+    pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff); 
+    pc.printf("t7.pco=%d\n\r", NORMAL_COLOR);
+    pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
+    pc.printf("t8.pco=%d\n\r", NORMAL_COLOR);
+    pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
+ */   
     /* Print default values */
     Volume_Setpoint_Fix();
     Resp_Frequency_Fix();
@@ -76,22 +90,16 @@
      /* Remove the selection box from the previous position */
       switch(past_parameter_selection_index){
             case 0:
-                nextion_display.printf("t6.pco=%d", NORMAL_COLOR);
+                nextion_display.printf("t1.pco=%d", NORMAL_COLOR);
                 nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-               // pc.printf("t6.pco=%d", NORMAL_COLOR);
-              //  pc.printf("%c%c%c", 0xff, 0xff, 0xff);
                 break;
             case 1:
+                nextion_display.printf("t4.pco=%d", NORMAL_COLOR);
+                nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+                break;
+            case 2:
                 nextion_display.printf("t7.pco=%d", NORMAL_COLOR);
                 nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-               // pc.printf("t7.pco=%d\n\r", NORMAL_COLOR);
-               // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
-                break;
-            case 2:
-                nextion_display.printf("t8.pco=%d", NORMAL_COLOR);
-                nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-               // pc.printf("t8.pco=%d\n\r", NORMAL_COLOR);
-               // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
                 break;
             default:
                 break;  
@@ -101,22 +109,16 @@
      /* Draw the selection box in the new position */ 
       switch(parameter_selection_index){
             case 0:
-                nextion_display.printf("t6.pco=%d", SELECT_COLOR);
+                nextion_display.printf("t1.pco=%d", SELECT_COLOR);
                 nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-               // pc.printf("t6.pco=%d", SELECT_COLOR);
-               // pc.printf("%c%c%c", 0xff, 0xff, 0xff);
                 break;
             case 1:
+                nextion_display.printf("t4.pco=%d", SELECT_COLOR);
+                nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+                break;
+            case 2:
                 nextion_display.printf("t7.pco=%d", SELECT_COLOR);
                 nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-               // pc.printf("t7.pco=%d\n\r", SELECT_COLOR);
-               // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
-                break;
-            case 2:
-                nextion_display.printf("t8.pco=%d", SELECT_COLOR);
-                nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-               // pc.printf("t8.pco=%d\n\r", SELECT_COLOR);
-               // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
                 break;
             default:
                 break;  
@@ -131,22 +133,16 @@
 
       switch(parameter_selection_index){
             case 0:
-                nextion_display.printf("t6.pco=%d", NORMAL_COLOR);
+                nextion_display.printf("t1.pco=%d", NORMAL_COLOR);
                 nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-               // pc.printf("t6.pco=%d", NORMAL_COLOR);
-               // pc.printf("%c%c%c", 0xff, 0xff, 0xff);
                 break;
             case 1:
+                nextion_display.printf("t4.pco=%d", NORMAL_COLOR);
+                nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+                break;
+            case 2:
                 nextion_display.printf("t7.pco=%d", NORMAL_COLOR);
                 nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-              //  pc.printf("t7.pco=%d\n\r", NORMAL_COLOR);
-               // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
-                break;
-            case 2:
-                nextion_display.printf("t8.pco=%d", NORMAL_COLOR);
-                nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-               // pc.printf("t8.pco=%d\n\r", NORMAL_COLOR);
-               // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
                 break;
             default:
                 break;   
@@ -162,10 +158,8 @@
     volume_setpoint_display = VOLUME_SETPOINT_MINIMUM_VALUE  + VOLUME_SETPOINT_STEP*volume_setpoint_index;
     
     /* Print volume value */
-    nextion_display.printf("t6.txt=\"%d mL\"", volume_setpoint_display);
+    nextion_display.printf("t1.txt=\"%d\"", volume_setpoint_display);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-   // pc.printf("t6.txt=\"%d mL\"\n\r", volume_setpoint_display);
-   // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
 } 
 
 
@@ -175,10 +169,8 @@
     stepper_parameters_update_flag = 1;
     
     /* Print volume value */
-    nextion_display.printf("t6.txt=\"%d mL\"", volume_setpoint_display);
+    nextion_display.printf("t1.txt=\"%d\"", volume_setpoint_display);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-   // pc.printf("t6.txt=\"%d mL\"\n\r", volume_setpoint_display);
-   // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
 } 
 
 
@@ -187,10 +179,8 @@
     resp_frequency_display = 10 + resp_frequency_index;
     
     /* Print frequency value */
-    nextion_display.printf("t7.txt=\"%d RPM\"", resp_frequency_display);
+    nextion_display.printf("t4.txt=\"%d\"", resp_frequency_display);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-   // pc.printf("t7.txt=\"%d RPM\"\n\r", resp_frequency_display);
-   // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
 }  
 
 
@@ -200,11 +190,8 @@
     stepper_parameters_update_flag = 1;
     
     /* Print frequency value */
-    nextion_display.printf("t7.txt=\"%d RPM\"", resp_frequency_display);
+    nextion_display.printf("t4.txt=\"%d\"", resp_frequency_display);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-  //  pc.printf("t7.txt=\"%d RPM\"\n\r", resp_frequency_display);
-  //  pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);    
- 
 }  
 
 void I_E_Ratio_Display_Update(void){
@@ -213,10 +200,8 @@
     expiration_time_display = i_e_ratio_display_table[i_e_ratio_index][1];
     
     /* Print i:e ratio value */
-    nextion_display.printf("t8.txt=\"%2.1f/%2.1f\"", inspiration_time_display, expiration_time_display);
-    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-   // pc.printf("t8.txt=\"%2.1f/%2.1f\"\n\r", inspiration_time_display, expiration_time_display);
-   // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);   
+    nextion_display.printf("t7.txt=\"%2.1f : %2.1f\"", inspiration_time_display, expiration_time_display);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff); 
 }  
 
 
@@ -227,23 +212,120 @@
     stepper_parameters_update_flag = 1;
     
     /* Print i:e ratio value */
-    nextion_display.printf("t8.txt=\"%2.1f/%2.1f\"", inspiration_time_display, expiration_time_display);
+    nextion_display.printf("t7.txt=\"%2.1f : %2.1f\"", inspiration_time_display, expiration_time_display);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-   // pc.printf("t8.txt=\"%2.1f/%2.1f\"\n\r", inspiration_time_display, expiration_time_display);
-   // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
 }  
 
-void Pressure_01_Display_Update(void){
-    nextion_display.printf("t1.txt=\"%.2f mL\"", pressure_01_psi);
+void Volume_Display_Update(void){
+    nextion_display.printf("t11.txt=\"%.2f\"", volume_ml);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+}
+
+void Pressure_Display_Update(void){
+    nextion_display.printf("t15.txt=\"%.1f\"", (pressure_02_psi * PSI_TO_CMH2O_CONSTANT));
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+}
+
+void Flow_Display_Update(void){
+    nextion_display.printf("t14.txt=\"%.2f\"", flow_lpm);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
 }
 
-void Pressure_02_Display_Update(void){
-    nextion_display.printf("t2.txt=\"%.2f mL\"", pressure_02_psi);
+
+void Nextion_Plot_Volume_Waveform(void){
+    
+    static uint16_t x_pos_counter = 1, prev_y_pos = (VOLUME_WAVEFORM_Y0 + VOLUME_WAVEFORM_HEIGHT - 1);
+    int16_t x_pos, y_pos;
+    uint16_t volume_scaled_value;
+    
+    //volume_scaled_value = (uint16_t)((volume_ml - 0.5)*VOLUME_WAVEFORM_HEIGHT*2) ;
+    volume_scaled_value = (uint16_t)((volume_ml - 0.5)*2) ;
+    
+    x_pos_counter++;
+    
+    if(x_pos_counter >= VOLUME_WAVEFORM_WIDTH){
+        nextion_display.printf("fill %d,%d,%d,%d,%d",VOLUME_WAVEFORM_X0,VOLUME_WAVEFORM_Y0,VOLUME_WAVEFORM_WIDTH,VOLUME_WAVEFORM_HEIGHT,8591);
+        nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+        x_pos_counter = 1;
+    }
+    
+    x_pos = VOLUME_WAVEFORM_X0 + x_pos_counter;
+    y_pos = VOLUME_WAVEFORM_Y0 + VOLUME_WAVEFORM_HEIGHT - volume_scaled_value - 1;
+    
+    if(y_pos <= VOLUME_WAVEFORM_Y0){
+        y_pos = VOLUME_WAVEFORM_Y0 + 1;
+    }
+    
+    nextion_display.printf("line %d,%d,%d,%d,%d",(x_pos - 1), prev_y_pos, x_pos, y_pos, GREEN);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+    
+    prev_y_pos = y_pos; 
 }
 
-void Diff_Pressure_Display_Update(void){
-    nextion_display.printf("t0.txt=\"%.2f mL\"", diff_pressure_psi);
+
+void Nextion_Plot_Flow_Waveform(void){
+    
+    static uint16_t x_pos_counter = 1, prev_y_pos = (FLOW_WAVEFORM_Y0 + FLOW_WAVEFORM_HEIGHT - 1);
+    uint16_t x_pos, y_pos;
+    uint16_t flow_scaled_value;
+    
+    flow_scaled_value = 79 + (int16_t)(flow_lpm * FLOW_WAVEFORM_HEIGHT);
+    
+    x_pos_counter++;
+    
+    if(x_pos_counter >= FLOW_WAVEFORM_WIDTH){
+        nextion_display.printf("fill %d,%d,%d,%d,%d",FLOW_WAVEFORM_X0,FLOW_WAVEFORM_Y0,FLOW_WAVEFORM_WIDTH,FLOW_WAVEFORM_HEIGHT,8591);
+        nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+        x_pos_counter = 1;
+    }
+    
+    x_pos = FLOW_WAVEFORM_X0 + x_pos_counter;
+    y_pos = FLOW_WAVEFORM_Y0 + FLOW_WAVEFORM_HEIGHT - flow_scaled_value - 1;
+    
+    
+    if(y_pos <= FLOW_WAVEFORM_Y0){
+        y_pos = VOLUME_WAVEFORM_Y0 + 1;
+    }else if(y_pos >= (FLOW_WAVEFORM_Y0 + FLOW_WAVEFORM_HEIGHT)){
+        y_pos = VOLUME_WAVEFORM_Y0 + FLOW_WAVEFORM_HEIGHT - 1;
+    
+    }
+    
+    
+    
+    nextion_display.printf("line %d,%d,%d,%d,%d",(x_pos - 1), prev_y_pos, x_pos, y_pos, YELLOW);
     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
-}
\ No newline at end of file
+    
+    prev_y_pos = y_pos; 
+}
+
+
+void Nextion_Plot_Pressure_Waveform(void){
+    
+    static uint16_t x_pos_counter = 1, prev_y_pos = (PRESSURE_WAVEFORM_Y0 + PRESSURE_WAVEFORM_HEIGHT - 1);
+    uint16_t x_pos, y_pos;
+    uint16_t pressure_02_scaled_value;
+    
+    pressure_02_scaled_value = (uint16_t)((pressure_02_psi - 0.5)*PRESSURE_WAVEFORM_HEIGHT*2) ;
+    
+    x_pos_counter++;
+    
+    if(x_pos_counter >= PRESSURE_WAVEFORM_WIDTH){
+        nextion_display.printf("fill %d,%d,%d,%d,%d",PRESSURE_WAVEFORM_X0,PRESSURE_WAVEFORM_Y0,PRESSURE_WAVEFORM_WIDTH,PRESSURE_WAVEFORM_HEIGHT,8591);
+        nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+        x_pos_counter = 1;
+    }
+    
+    x_pos = PRESSURE_WAVEFORM_X0 + x_pos_counter;
+    y_pos = PRESSURE_WAVEFORM_Y0 + PRESSURE_WAVEFORM_HEIGHT - pressure_02_scaled_value - 1;
+    
+    
+    if(y_pos <= PRESSURE_WAVEFORM_Y0){
+        y_pos = PRESSURE_WAVEFORM_Y0 + 1;
+    }
+    
+    nextion_display.printf("line %d,%d,%d,%d,%d",(x_pos - 1), prev_y_pos, x_pos, y_pos, WHITE);
+    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+    
+    prev_y_pos = y_pos; 
+}
+

--- a/nextion_interface.h	Mon Apr 20 21:58:36 2020 +0000
+++ b/nextion_interface.h	Thu Apr 23 17:05:36 2020 +0000
@@ -3,6 +3,7 @@
 #define NEXTION_INTERFACE_H_
 
 /* File inclusion */
+#include "mbed.h"
 #include "stdint.h"
 
 /* Object declaration */
@@ -38,11 +39,13 @@
 void I_E_Ratio_Display_Update(void);
 void I_E_Ratio_Fix(void);
 
-void Pressure_01_Display_Update(void);
-void Pressure_02_Display_Update(void);
-void Diff_Pressure_Display_Update(void);
+void Volume_Display_Update(void);
+void Pressure_Display_Update(void);
+void Flow_Display_Update(void);
 
-
+void Nextion_Plot_Volume_Waveform(void);
+void Nextion_Plot_Flow_Waveform(void);
+void Nextion_Plot_Pressure_Waveform(void);
 
 
 #endif
\ No newline at end of file

--- a/pressure_sensors.cpp	Mon Apr 20 21:58:36 2020 +0000
+++ b/pressure_sensors.cpp	Thu Apr 23 17:05:36 2020 +0000
@@ -1,6 +1,7 @@
 
 #include "mbed.h"
 #include "stdint.h"
+#include "math.h"
 #include "project_defines.h"
 #include "pressure_sensors.h"
 
@@ -10,9 +11,11 @@
 I2C pressure_sensor_02(PRESSURE_SENSOR_02_SDA_PIN, PRESSURE_SENSOR_02_SCL_PIN);
 
 /* Global variable definition */
-uint16_t pressure_01_bin, pressure_02_bin, diff_pressure_bin;
-float pressure_01_psi, pressure_02_psi; 
-float diff_pressure_psi;
+int16_t pressure_01_bin, pressure_02_bin;
+float pressure_01_psi, pressure_02_psi;
+float flow_lpm, volume_ml;
+
+//float diff_pressure_psi;
 
 char sensor_read_data_buffer[2];
 
@@ -31,13 +34,47 @@
     pressure_01_bin = ((sensor_read_data_buffer[0] << 8) | sensor_read_data_buffer[1]) & 0x3FFF;
     pressure_sensor_02.read(PRESSURE_SENSOR_02_SRA, sensor_read_data_buffer, 2);
     pressure_02_bin = ((sensor_read_data_buffer[0] << 8) | sensor_read_data_buffer[1]) & 0x3FFF;
-    diff_pressure_bin =  pressure_01_bin - pressure_02_bin;
     
     /* Calculate pressure values in PSI */
     pressure_01_psi = (5.0 * pressure_01_bin) / 16383; 
     pressure_02_psi = (5.0 * pressure_02_bin) / 16383;
-    diff_pressure_psi = (5.0 * diff_pressure_bin) / 16383;
+
     
 } 
 
+void Calculate_Flow_From_Pressure(void){
+    
+    int16_t diff_pressure_bin;
+    float diff_pressure_psi;
+    
+    diff_pressure_bin =  pressure_02_bin - pressure_01_bin;
+    diff_pressure_psi = (5.0 * diff_pressure_bin) / 16383;
+    
+    if(diff_pressure_psi < 0){
+        flow_lpm = -SPIROMETER_SENSOR_CONSTANT * sqrt(-diff_pressure_psi);    
+    }else{
+        flow_lpm = SPIROMETER_SENSOR_CONSTANT * sqrt(diff_pressure_psi);  
+    }    
+}
 
+void Calculate_Volume_From_Flow(void){
+    
+    static float previous_flow_lpm = 0.0;
+    float delta_volume_ml;
+    
+    delta_volume_ml = (PRESSURE_SENSOR_READ_PERIOD_MS * (flow_lpm + previous_flow_lpm)) / 60.0;
+    
+    volume_ml = volume_ml + delta_volume_ml;
+    
+    previous_flow_lpm = flow_lpm;
+    
+}
+
+void Pressure_01_LPF(void){
+
+}
+
+
+void Pressure_02_LPF(void){
+
+}

--- a/pressure_sensors.h	Mon Apr 20 21:58:36 2020 +0000
+++ b/pressure_sensors.h	Thu Apr 23 17:05:36 2020 +0000
@@ -5,14 +5,19 @@
 #include "stdint.h"
 
 /* Global variable declaration */
-extern uint16_t pressure_01_bin, pressure_02_bin, diff_pressure_bin;
-extern float pressure_01_psi, pressure_02_psi; 
-extern float diff_pressure_psi;
+extern int16_t pressure_01_bin, pressure_02_bin;
+extern float pressure_01_psi, pressure_02_psi;
+extern float flow_lpm, volume_ml;
+//extern float diff_pressure_psi;
 
 extern char sensor_read_data_buffer[2]; 
 
 /* Function declaration */
 void Pressure_Sensors_Initialize(void);
 void Pressure_Sensors_Read(void);
+void Calculate_Flow_From_Pressure(void);
+void Calculate_Volume_From_Flow(void);
+void Pressure_01_LPF(void);
+void Pressure_02_LPF(void);
 
 #endif
\ No newline at end of file

--- a/project_defines.h	Mon Apr 20 21:58:36 2020 +0000
+++ b/project_defines.h	Thu Apr 23 17:05:36 2020 +0000
@@ -20,11 +20,10 @@
 #define NEXTION_DISPLAY_RX_PIN                  PC_11
 
 // Pressure sensors
-#define PRESSURE_SENSOR_01_SDA_PIN              PB_9
-#define PRESSURE_SENSOR_01_SCL_PIN              PB_8
-
-#define PRESSURE_SENSOR_02_SDA_PIN              PB_10
-#define PRESSURE_SENSOR_02_SCL_PIN              PB_11
+#define PRESSURE_SENSOR_01_SCL_PIN              PB_10
+#define PRESSURE_SENSOR_01_SDA_PIN              PB_11
+#define PRESSURE_SENSOR_02_SCL_PIN              PB_8
+#define PRESSURE_SENSOR_02_SDA_PIN              PB_9
 
 //Stepper motor
 #define STEPPER_PULSE_PIN                       PC_8
@@ -40,6 +39,8 @@
 #define LIMIT_SW_01                             1
 #define GAS_INPUT_SW                            2
 
+#define DEBOUNCE_PERIOD_MS                      10
+
 /* Defines for the encoder user interface */
 #define ENCODER_THRESHOLD                       8
 
@@ -53,9 +54,11 @@
 #define RESP_FREQUENCY_INDEX_DEFAULT            10
 #define I_E_RATIO_INDEX_DEFAULT                 0
 
+#define ENCODER_READ_PERIOD_MS                  50
+
 /* Defines for the Nextion user interface */
 
-#define NEXTION_DISPLAY_BAUD_RATE               9600
+#define NEXTION_DISPLAY_BAUD_RATE               115200
 
 #define BLACK                                   0
 #define BLUE                                    31
@@ -66,25 +69,10 @@
 #define GRAY                                    33840
 #define WHITE                                   65535
 
-#define NORMAL_COLOR                            BLACK
+#define NORMAL_COLOR                            WHITE
 #define SELECT_COLOR                            BLUE
 #define ADJUST_COLOR                            GREEN
 
-//#define BACKGROUND_COLOR                        Black
-//#define INDICATOR_BOX_LINE_COLOR                Green
-//#define INDICATOR_HEADER_TEXT_COLOR             Yellow
-//#define INDICATOR_VALUE_TEXT_COLOR              White
-//#define INDICATOR_UNITS_TEXT_COLOR              White
-//#define PARAMETER_SELECTION_BOX_COLOR           Yellow
-//#define PARAMETER_ADJUST_TEXT_COLOR             Green 
-
-#define HEADERS_ROW1_Y_POS                      20
-#define HEADERS_ROW2_Y_POS                      180
-#define UNITS_ROW1_Y_POS                        103
-#define UNITS_ROW2_Y_POS                        263
-#define VALUES_ROW1_Y_POS                       60
-#define VALUES_ROW2_Y_POS                       220
-
 #define VOLUME_SETPOINT_VALUE_DEFAULT           500
 #define RESP_FREQUENCY_VALUE_DEFAULT            20
 #define INSPIRATION_TIME_VALUE_DEFAULT          1.0
@@ -96,7 +84,25 @@
 #define AIR_INPUT                               0
 #define OXYGEN_INPUT                            1
 
-#define MAIN_SCREEN_DEFAULT_STATE                       Main_Screen_Cursor_Disable
+#define MAIN_SCREEN_DEFAULT_STATE               Main_Screen_Cursor_Disable
+
+#define VOLUME_WAVEFORM_X0                      200
+#define VOLUME_WAVEFORM_Y0                      3
+#define VOLUME_WAVEFORM_WIDTH                   400
+#define VOLUME_WAVEFORM_HEIGHT                  157
+
+#define FLOW_WAVEFORM_X0                        200
+#define FLOW_WAVEFORM_Y0                        162
+#define FLOW_WAVEFORM_WIDTH                     400
+#define FLOW_WAVEFORM_HEIGHT                    157
+
+#define PRESSURE_WAVEFORM_X0                    200
+#define PRESSURE_WAVEFORM_Y0                    321
+#define PRESSURE_WAVEFORM_WIDTH                 400
+#define PRESSURE_WAVEFORM_HEIGHT                157
+
+#define SENSOR_WAVEFORM_PLOT_PERIOD_MS          25
+#define SENSOR_DISPLAY_PERIOD_MS                100
 
 /* Defines for the pressure sensors */
 #define PRESSURE_SENSOR_I2C_CLK_HZ                      200000
@@ -106,8 +112,16 @@
 #define PRESSURE_SENSOR_02_SWA                          (PRESSURE_SENSOR_02_SLAVE_ADDRESS << 1)
 #define PRESSURE_SENSOR_01_SRA                          (PRESSURE_SENSOR_01_SWA  | 1)
 #define PRESSURE_SENSOR_02_SRA                          (PRESSURE_SENSOR_02_SWA  | 1)
+
+#define VOLUME_DISPLAY_THRESHOLD                        0.01f
+#define FLOW_DISPLAY_THRESHOLD                          0.01f
 #define PRESSURE_DISPLAY_THRESHOLD                      0.01f
 
+#define PSI_TO_CMH2O_CONSTANT                           70.307
+#define SPIROMETER_SENSOR_CONSTANT                      1.0f
+
+#define PRESSURE_SENSOR_READ_PERIOD_MS                  1
+
 /* Defines for the stepper motor control */ 
 #define TO_HOME                                         0
 #define TO_AIRBAG                                       1
@@ -142,6 +156,6 @@
 #define STEPPER_START_BRAKE_PERIOD_US                   (1000000.0/STEPPER_START_BRAKE_FREQUENCY_HZ)
 #define SHORT_RAMP_STEPS                                25
 
-#define TUNING_FACTOR                                   1.25
+#define TUNING_FACTOR                                   1.2
 
 #endif

--- a/ventilator.cpp	Mon Apr 20 21:58:36 2020 +0000
+++ b/ventilator.cpp	Thu Apr 23 17:05:36 2020 +0000
@@ -8,8 +8,12 @@
 #include "encoder_interface.h"
 #include "nextion_interface.h"
 #include "pressure_sensors.h"
+#include "stepper_motor_driver.h"
 #include "ventilator.h"
 
+/* Object definition */
+Ticker ticker_int_1ms; // Ticker interrupt
+
 
 /* Global variable definition */
 
@@ -30,6 +34,16 @@
 uint8_t first_time_in_state = 1;
 
 /* Function definition */
+
+void System_Initialize(void){
+    Buttons_Initialize();
+    Nextion_Interface_Initialize();
+    Pressure_Sensors_Initialize();
+    ticker_int_1ms.attach(&Ticker_ISR, 0.001);
+    Stepper_Driver_Init();
+}
+
+
 void Nextion_Encoder_Interaction(void){
 
  switch(main_screen_state){
@@ -37,6 +51,7 @@
                 if(Get_Button_Press(1 << ENTER_SW)){
                     rotary_encoder.reset();
                     main_screen_state = Main_Screen_Cursor_Enable;
+                    first_time_in_state = 1;
                 }
                 
                 break;  
@@ -63,7 +78,7 @@
             case Main_Screen_Volume_Setpoint_Adjust:
                 if(first_time_in_state){
                     first_time_in_state = 0;
-                    nextion_display.printf("t6.pco=%d", ADJUST_COLOR); // Change font color
+                    nextion_display.printf("t1.pco=%d", ADJUST_COLOR); // Change font color
                     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
                    // pc.printf("t6.pco=%d\n\r", ADJUST_COLOR); // Change font color
                    // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
@@ -87,7 +102,7 @@
             case Main_Screen_Resp_Frequency_Adjust:
                 if(first_time_in_state){
                     first_time_in_state = 0;
-                    nextion_display.printf("t7.pco=%d", ADJUST_COLOR); // Change font color
+                    nextion_display.printf("t4.pco=%d", ADJUST_COLOR); // Change font color
                     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
                    // pc.printf("t7.pco=%d\n\r", ADJUST_COLOR); // Change font color
                    // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
@@ -112,7 +127,7 @@
             case Main_Screen_I_E_Ratio_Adjust:
                 if(first_time_in_state){
                     first_time_in_state = 0;
-                    nextion_display.printf("t8.pco=%d", ADJUST_COLOR); // Change font color
+                    nextion_display.printf("t7.pco=%d", ADJUST_COLOR); // Change font color
                     nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
                     //pc.printf("t8.pco=%d\n\r", ADJUST_COLOR); // Change font color
                    // pc.printf("%c%c%c\n\r", 0xff, 0xff, 0xff);
@@ -142,54 +157,84 @@
  
  void Nextion_Update_Sensor_Values(void){
     
-    static float previous_pressure_01_psi = 0, previous_pressure_02_psi = 0;
-    static float previous_diff_pressure_psi = 0;
+    static float previous_pressure_02_psi = 0;
+    static float previous_volume_ml = 0;
+    static float previous_flow_lpm = 0;
     float delta;
     
     /* Check if anu value has change in a meningful way */
-    delta = pressure_01_psi - previous_pressure_01_psi;
-    if((delta > PRESSURE_DISPLAY_THRESHOLD) || (delta < -PRESSURE_DISPLAY_THRESHOLD)){
-        Pressure_01_Display_Update();
+    delta = volume_ml - previous_volume_ml;
+    if((delta > VOLUME_DISPLAY_THRESHOLD) || (delta < -PRESSURE_DISPLAY_THRESHOLD)){
+        Volume_Display_Update();
     } 
     
     delta = pressure_02_psi - previous_pressure_02_psi;
     if((delta > PRESSURE_DISPLAY_THRESHOLD) || (delta < -PRESSURE_DISPLAY_THRESHOLD)){
-        Pressure_02_Display_Update();
+        Pressure_Display_Update();
     }
     
-    delta = diff_pressure_psi - previous_diff_pressure_psi;
-    if((delta > PRESSURE_DISPLAY_THRESHOLD) || (delta < -PRESSURE_DISPLAY_THRESHOLD)){
-        Diff_Pressure_Display_Update();
+    delta = flow_lpm - previous_flow_lpm;
+    if((delta > FLOW_DISPLAY_THRESHOLD) || (delta < -PRESSURE_DISPLAY_THRESHOLD)){
+        Flow_Display_Update();
     }    
     
     
     /* Update the previous values */
-    previous_pressure_01_psi = pressure_01_psi;
+    previous_volume_ml = volume_ml;
     previous_pressure_02_psi = pressure_02_psi;
-    previous_diff_pressure_psi = diff_pressure_psi;
- 
+    previous_flow_lpm = flow_lpm;
+
  }
  
  
-  void Nextion_Update_Waveform_Values(void){
- 
-    uint8_t pressure_graph_val;
-    
-    /* Plot pressure 01 in a 0 to 1 PSI scale */
-    pressure_graph_val = (uint8_t)(pressure_01_psi * 128);
-    nextion_display.printf("add 10,0,%d", pressure_graph_val);
-    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);
+void Nextion_Update_Waveform_Values(void){
+    Nextion_Plot_Volume_Waveform();  
+    Nextion_Plot_Pressure_Waveform();  
+    Nextion_Plot_Flow_Waveform(); 
+}
+
+
+// Ticker Interrupt Service Routine
+void Ticker_ISR(void){
+   
+    static uint8_t debounce_conta_1ms = 0;
+    static uint8_t encoder_conta_1ms = 0;
+    static uint8_t sensor_conta_1ms = 0;
+    static uint8_t sensor_waveform_conta_1ms = 0;
+    static uint8_t sensor_display_conta_1ms = 0;
+     
+    debounce_conta_1ms++;
+    encoder_conta_1ms++;
+    sensor_conta_1ms++;
+    sensor_waveform_conta_1ms++;
+    sensor_display_conta_1ms++;
     
-    /* Plot pressure 02 in a 0 to 1 PSI scale */
-    pressure_graph_val = (uint8_t)(pressure_02_psi * 128);
-    nextion_display.printf("add 11,0,%d", pressure_graph_val); 
-    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff); 
-    
-    /* Plot differential pressure in a -1 PSI to 1 PSI scale */
-    pressure_graph_val = 64 + (uint8_t)(diff_pressure_psi * 64);
-    nextion_display.printf("add 1,0,%d", pressure_graph_val);
-    nextion_display.printf("%c%c%c", 0xff, 0xff, 0xff);  
- 
-  }
+    // Read buttons and performs debounce action
+    if(debounce_conta_1ms == DEBOUNCE_PERIOD_MS){
+        debounce_conta_1ms = 0;
+        Button_Debounce();
+    }    
+    // Read encoder and update the proper indexes    
+    if(encoder_conta_1ms == ENCODER_READ_PERIOD_MS){
+        encoder_conta_1ms = 0;
+        Encoder_Read();
+    }        
+    // Indicates if it is time to acquire a new sample from the sensors
+    if(sensor_conta_1ms == PRESSURE_SENSOR_READ_PERIOD_MS){
+        sensor_conta_1ms = 0;
+        read_pressure_sensors_flag = 1;
+    }       
+    // Indicates if it is time to plot the volume, flow and pressure values */   
+    if(sensor_waveform_conta_1ms  == SENSOR_WAVEFORM_PLOT_PERIOD_MS){
+        sensor_waveform_conta_1ms  = 0;
+        pressure_sensor_waveform_update_flag = 1;
+    }    
+    // Indicates if it is time to display the volume, flow and pressure values */   
+    if(sensor_display_conta_1ms  == SENSOR_DISPLAY_PERIOD_MS){
+        sensor_display_conta_1ms  = 0;
+        pressure_sensor_display_update_flag = 1;
+    }               
+        
+}
  
         
\ No newline at end of file

--- a/ventilator.h	Mon Apr 20 21:58:36 2020 +0000
+++ b/ventilator.h	Thu Apr 23 17:05:36 2020 +0000
@@ -16,6 +16,11 @@
     Main_Screen_I_E_Ratio_Adjust = 4
 }Main_Screen_State_t;
 
+
+/* Object declaration */
+extern Ticker ticker_int_1ms;
+
+
 /* Global variable declaration */
 extern volatile uint8_t read_pressure_sensors_flag;
 extern volatile uint8_t pressure_sensor_display_update_flag;
@@ -34,10 +39,11 @@
 
 
 /* Function declaration */
+void System_Initialize(void);
 void Nextion_Encoder_Interaction(void);
 void Nextion_Update_Sensor_Values(void);
 void Nextion_Update_Waveform_Values(void);
-
+void Ticker_ISR(void); // ISR that is called when the timer reaches the set value
 
 /* Inline functions */
 static inline void Encoder_Read(){