Diff: main.cpp

Revision:

3:fa37b0c705b3

Parent:

2:d329886938f1

--- a/main.cpp	Wed Aug 23 19:04:51 2017 +0000
+++ b/main.cpp	Sun Nov 26 21:56:10 2017 +0000
@@ -3,34 +3,65 @@
 
 DigitalOut led(LED1);
 
-Serial pc(USBTX, USBRX); // tx, rx
+MAX30100 max;
+uint32_t tsLastPollUs = 0;
+
+// Tweakable parameters
+// Sampling and polling frequency must be set consistently
+#define POLL_PERIOD_US                      1E06 / 100
+#define SAMPLING_RATE                       MAX30100_SAMPRATE_100HZ
 
-MAX30100 max;
+// The LEDs currents must be set to a level that avoids clipping and maximises the
+// dynamic range
+#define IR_LED_CURRENT                      MAX30100_LED_CURR_50MA
+#define RED_LED_CURRENT                     MAX30100_LED_CURR_27_1MA
+
+// The pulse width of the LEDs driving determines the resolution of
+// the ADC (which is a Sigma-Delta).
+// set HIGHRES_MODE to true only when setting PULSE_WIDTH to MAX30100_SPC_PW_1600US_16BITS
+#define PULSE_WIDTH                         MAX30100_SPC_PW_1600US_16BITS
+#define HIGHRES_MODE                        true
 
 int main() {
-    max.begin(pw1600, i50, sr100);
-    max.setLEDs(pw1600, i27, i50);
-    
-    int partID = max.getPartID();
-    
-    if(partID == POR_PART_ID){
-        pc.printf("MAX30100 is online...\n\r");    
-    }
-    
-    else{
-        pc.printf("MAX30100 is offline...\n\r");
-        pc.printf("Value is %d\n\r",partID);
-        pc.printf("Should be %d\n\r",POR_PART_ID);
-        while(1){
-            wait(1);
-        }
-    }
-    
-    int revID = max.getRevID();
-    
-    pc.printf("RevID is %d\n\r",revID);
-    
-    //max.setLEDs(pw1600, i50, i14);
-    
+/*
+pc.printf("POR State:\n\r");
+max.printRegisters();
+pc.printf("\n\r");
+
+max.begin();
+pc.printf("Begin State:\n\r");
+max.printRegisters();
+wait(1);
+pc.printf("\n\r");
+
+max.setMode(MAX30100_MODE_SPO2_HR);
+pc.printf("\n\rSPO2 and HR Mode:\n\r");
+max.printRegisters();
+wait(1);
+
+pc.printf("\n\rSetting LEDs to 50mA:\n\r");
+max.setLedsCurrent(MAX30100_LED_CURR_50MA, MAX30100_LED_CURR_50MA);
+max.printRegisters();
+wait(10);
+
+pc.printf("\n\rSetting LEDs to 7.6mA\n\r");
+max.setLedsCurrent(MAX30100_LED_CURR_7_6MA, MAX30100_LED_CURR_7_6MA);
+max.printRegisters();
+pc.printf("\n\r");
 return 1;
+*/
+max.begin();
+max.setMode(MAX30100_MODE_SPO2_HR);
+max.setLedsCurrent(IR_LED_CURRENT, RED_LED_CURRENT);
+max.setLedsPulseWidth(PULSE_WIDTH);
+max.setSamplingRate(SAMPLING_RATE);
+max.setHighresModeEnabled(HIGHRES_MODE);
+
+while(1){
+if(us_ticker_read() < tsLastPollUs || us_ticker_read() - tsLastPollUs > POLL_PERIOD_US){
+    max.update();
+    tsLastPollUs = us_ticker_read();
+    pc.printf("$%d %d;", max.rawIRValue/10, max.rawRedValue/10);
 }
+}
+}