Revision 2:39d6246ca2cb, committed 2019-02-21

Comitter:

MadhuraT

Date:

Thu Feb 21 19:55:58 2019 +0000

Parent:

1:f7e85b6d0117

Commit message:

rEV0

Changed in this revision

--- a/main.cpp	Tue Feb 19 22:27:27 2019 +0000
+++ b/main.cpp	Thu Feb 21 19:55:58 2019 +0000
@@ -2,12 +2,13 @@
 #include "USBSerial.h"
 #include "max32625pico.h"
 
-USBSerial pc;
+USBSerial pc;      //Serial Terminal, specific to pico board
 
-double readPwrMonitor(I2C &i2cbus, int channel_no);
-void configPwrMonitor(I2C &i2cbus);
+double readPwrMonitor(I2C &i2cbus, int channel_no); //Function to read power values from MAX34417
+void configPwrMonitor(I2C &i2cbus);                 //Function to configure the power monitor device MAX34417
 
-#define I2C_SLAVE_ADDRESS 0X10
+#define I2C_SLAVE_WRITE_ADDRESS 0x20
+#define I2C_SLAVE_READ_ADDRESS 0x21
 #define REG_UPDATE     0x00
 #define REG_CONTROL    0x01
 #define REG_ACC_COUNT  0x02
@@ -22,6 +23,7 @@
 #define REG_DID        0x10
 #define REG_BULK_UPDATE 0x11
 #define REG_BULK_POWER_READOUT  0x06
+#define senseresistor 10
 #define REG_BULK_VOLTAGE_READOUT 0x07
 
 
@@ -30,8 +32,9 @@
 {
     int channel_no;
     int device_id;
-    char *dev_id;
+    char dev_id[2];
     char data_val[2]= {0x0F,0};
+    int status,status1;
     //initialize the MAX32625PICO board for +3.3V logic levels
     MAX32625PICO pico(MAX32625PICO::IOH_3V3, MAX32625PICO::VIO_IOH, MAX32625PICO::VIO_IOH);
     
@@ -46,19 +49,20 @@
 
     
     //delcare variables to store the raw power readings and the converted power readings
-    int power_raw;
+    double power_raw;
     double power_W;
-    double step1results, step2results, step3results, senseresistor1;
-    
-    i2c.write(I2C_SLAVE_ADDRESS,data_val, 1, false);
-    i2c.read(I2C_SLAVE_ADDRESS,dev_id, 1, false);
-    if(*dev_id == 0x07)
+    double step1results, step2results, step3results,senseresistor1;
+     
+    status= i2c.write(I2C_SLAVE_WRITE_ADDRESS,data_val, 1, true);
+    status1=i2c.read(I2C_SLAVE_READ_ADDRESS,dev_id, 1, false);
+     
+    if(dev_id[0] == 44)
     {
         pc.printf ("Device Found \n");
     }
     else
     {
-        pc.printf ("Device not found \n");
+        pc.printf ("Device not found");
     }
     //write the configuration register
     configPwrMonitor(i2c);
@@ -66,24 +70,25 @@
     //the while loop will read the power raw reading, convert to actual power data, and then
     //print the result to a serial terminal. It will then toggle each on-board LED
     //for 11ms for a total of 33ms. A new power value is available every 12.5ms.
-    while (true) {
-        //the readPwrMonitor() function returns a raw 24-bit power accumulator reading
+      while (true) {
+        //the readPwrMonitor() function returns a raw 56-bit power accumulator reading
         //if successful and a zero if unsuccessful
         for (channel_no=0; channel_no <4 ; channel_no ++)
         {
         power_raw = readPwrMonitor(i2c,channel_no);
         
         //print poweronly if valid data is received. 
-        if(power_raw != 0)
+        if(status1 == 0)
         {
             step1results=power_raw;
             step2results = (double)step1results / (double)(1073741824);
-            senseresistor1 = 0.001 *senseresistor1;
+            senseresistor1 = 0.001 *senseresistor;
             step3results = step2results * ((.1 / senseresistor1) * 24);
             power_W = step3results;
             
             //print a floating point value with 4 decimal places
-            pc.printf("\r\n%.4f C",power_W);
+            pc.printf("\r\n Channel %d : Power (W)= %.4f ",channel_no, power_W);
+            
         }
         else {
             pc.printf("\r\nPowerMonitor Read Error");
@@ -110,25 +115,34 @@
     char data[2] = {REG_CONTROL, 0xA0};
     
     //this built-in I2C write function from mbed sends the configuration data to the MAX34417
-    i2cbus.write(I2C_SLAVE_ADDRESS, data, 2, false);
+    i2cbus.write(I2C_SLAVE_WRITE_ADDRESS, data, 2, false);
 }
 
 double readPwrMonitor(I2C &i2cbus, int channel)
 {
-    int pwr_raw = 0;
+    long pwr_raw = 0;
+    long PowerAccumulatorValue;
     char data[2]= {0, 0};
-    
+    char data1[4];
+    char data2[8];
+    int Accumulator_Counter;
     data[0] = REG_UPDATE;
     data[1] =0;
     
    
     //it returns a zero on success or non-zero if unsuccessful
-    int rtn_val = i2cbus.write(I2C_SLAVE_ADDRESS, data, 1, true);
+    int rtn_val = i2cbus.write(I2C_SLAVE_WRITE_ADDRESS, data, 1, true);
     
     //proceeds to read power only if previous command was successful
     if(rtn_val == 0)
     {
+        data[0]= REG_ACC_COUNT;
+        data[1] = 0;
         
+        rtn_val = i2cbus.write(I2C_SLAVE_WRITE_ADDRESS, data, 1, true);
+        rtn_val = i2cbus.read(I2C_SLAVE_READ_ADDRESS, data1, 4, false);
+        Accumulator_Counter= (int)((data1[1] << 16) + (data1[2] << 8) + data1[3]);
+ 
         {
         //this I2C command reads the power and stores it in the 'data' array.
         //it returns a zero on success or non-zero if unsuccessful
@@ -152,9 +166,10 @@
         data[0] = REG_PWR_ACC4;
         data[1] =0;
         }
-        rtn_val = i2cbus.read(I2C_SLAVE_ADDRESS, data, 1, false);
+        rtn_val = i2cbus.write(I2C_SLAVE_WRITE_ADDRESS, data, 1, true);
+        rtn_val = i2cbus.read(I2C_SLAVE_READ_ADDRESS, data2, 8, false);
         
-        //proceeds to format raw temperature data only if previous command was successful
+        //proceeds to format raw power data only if previous command was successful
         if(rtn_val == 0)
         {
             
@@ -162,9 +177,18 @@
         }
         
         }
-    }
-    pwr_raw=data[0];
+    PowerAccumulatorValue= (long)(
+                                                               ((long)data2[1] << (8 * 6)) +
+                                                               ((long)data2[2] << (8 * 5)) +
+                                                               ((long)data2[3] << (8 * 4)) +
+                                                               ((long)data2[4] << (8 * 3)) +
+                                                               ((long)data2[5] << (8 * 2)) +
+                                                               ((long)data2[6] << (8 * 1)) +
+                                                               ((long)data2[7] << (8 * 0)));
+   }                                                            
     //returns the power reading
+    pwr_raw=  (double)PowerAccumulatorValue/ (double)Accumulator_Counter;
+    
     return pwr_raw;
 }
     
\ No newline at end of file