Rex Ching / Mbed 2 deprecated MedtricsIOECG

ECG data acquisition with Analog device frontend and Redbear nano BLE

Dependencies:   BLE_API mbed nRF51822

Fork of BLENano_SimpleControls by RedBearLab

Reference Design

2 channel EKG with Redbear BLE reference and Analog Device amplifier to generate RAW EKG data fed into Medtrics MaaS service . Medtrics API can consumer raw input with given parameters of ADC sample frequency and scaling factor

Specification

  • Application Processor: nRF51822/BLE , Analog frontend: AD8232 /
  • Input Analog Voltage = 3.3V
  • 10 bit ADC input range = (0-1023) or scaling factor= 3.22mV/unit (this is ADC resolution)
  • ADC sample frequency (BLE pull rate) = 250Hz (4ms per sample)

/media/uploads/pkweitai/ble_-3-.jpg Reference IOS and Android app will be online soon!

Diff: main.cpp

Revision:
4:b95d3432a495
Parent:
3:f530ca03e014
--- a/main.cpp	Thu Jan 07 02:43:53 2016 +0000
+++ b/main.cpp	Sat Jan 07 06:20:36 2017 +0000
@@ -29,16 +29,20 @@
 #define TXRX_BUF_LEN                     20
 
 #define DIGITAL_OUT_PIN                  P0_9       //TXD
-#define DIGITAL_IN_PIN                   P0_10      //CTS
-#define PWM_PIN                          P0_11      //RXD
+#define DIGITAL_IN_PIN10                   P0_10      //CTS
+#define DIGITAL_IN_PIN11                   P0_11      //RXD
+
+//#define PWM_PIN                          P0_11      //RXD
 #define SERVO_PIN                        P0_8       //RTS
 #define ANALOG_IN_PIN                    P0_4       //P04
 
 BLE             ble;
 
 DigitalOut      LED_SET(DIGITAL_OUT_PIN);
-DigitalIn       BUTTON(DIGITAL_IN_PIN);
-PwmOut          PWM(PWM_PIN);
+DigitalIn       P10(DIGITAL_IN_PIN10);
+DigitalIn       P11(DIGITAL_IN_PIN11);
+
+//PwmOut          PWM(PWM_PIN);
 AnalogIn        ANALOG(ANALOG_IN_PIN);
 Servo           MYSERVO(SERVO_PIN);
 
@@ -108,8 +112,8 @@
         }
         else if(buf[0] == 0x02)
         {
-            float value = (float)buf[1]/255;
-            PWM = value;
+            //float value = (float)buf[1]/255;
+            //PWM = value;
         }
         else if(buf[0] == 0x03)
         {
@@ -118,8 +122,8 @@
         else if(buf[0] == 0x04)
         {
             analog_enabled = 0;
-            PWM = 0;
-            MYSERVO.write(0);
+            //PWM = 0;
+            //MYSERVO.write(0);
             LED_SET = 0;
             old_state = 0;    
         }
@@ -148,7 +152,12 @@
 void m_status_check_handle(void)
 {   
     uint8_t buf[3];
-    if (analog_enabled)  // if analog reading enabled
+    //if (analog_enabled)  // if analog reading enabled
+    if ( 1 &&  ((P10 ==1) || (P11==1)))
+    {
+        //idle
+    }
+    else
     {
         // Read and send out
         float s = ANALOG;
@@ -160,11 +169,11 @@
     }
     
     // If digital in changes, report the state
-    if (BUTTON != old_state)
-    {
-        old_state = BUTTON;
+    //if (BUTTON != old_state)
+   // {
+     //   old_state = BUTTON;
         
-        if (BUTTON == 1)
+        if (P10 == 1)
         {
             buf[0] = (0x0A);
             buf[1] = (0x01);
@@ -178,14 +187,14 @@
             buf[2] = (0x00);
            ble.updateCharacteristicValue(rxCharacteristic.getValueAttribute().getHandle(), buf, 3); 
         }
-    }
+    //}
 }
 
 
 int main(void)
 {   
     Ticker ticker;
-    ticker.attach_us(m_status_check_handle, 200000);
+    ticker.attach_us(m_status_check_handle, 4000);
     
     ble.init();
     ble.onDisconnection(disconnectionCallback);