Diff: MAX44009/MAX44009_lib.cpp

Revision:

3:85fc843a9d7d

Child:

5:9e751733a6f3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX44009/MAX44009_lib.cpp	Mon Oct 12 21:55:22 2020 +0000
@@ -0,0 +1,139 @@
+
+#include "mbed.h"
+#include "MAX44009_lib.h"
+
+// *****************************************************************************
+//   MAX44009_write_register(char, char, char)  writes single byte to MAX44009
+//                       char   I2C address
+//                       char   MAX44009 register address
+//                       char   data byte to be writen
+//   returns                    0 on success ACK, 1 on NACK 
+// *****************************************************************************
+
+int MAX44009_write_register(I2C *i2c, char I2C_add, char reg_add, char byte){
+    char data[2];               // char type ranges from 0 to 255 (8 bytes)
+    int error;
+    data[0] = reg_add;
+    data[1] = byte;
+    error = i2c->write(I2C_add,data,2);  // why send 2 bytes?
+    //if(DEBUG)db.printf("wr[%02X %02X %d]\r\n", data[0], data[1], error);
+    return error; 
+    
+}
+
+/// ****************************************************************************
+//   MAX44009_write_register(char, char, char *, int)  writes multiple bytes to MAX44009
+//                       char   I2C address
+//                       char   MAX44009 register address
+//                       char * data vector of bytes to be written
+//                       int    number of bytes to write
+//   returns                    0 on success ACK, 1 on NACK 
+// *****************************************************************************
+
+int MAX44009_write_register(I2C *i2c, char I2C_add, char reg_add, char *bytes, int n){
+    int i;   
+    //set start address
+    char data[16];
+    int error;                          
+    data[0] = reg_add; 
+    for(i=1;i<=n;i++){                   
+       data[i] = bytes[i-1];
+    }
+    error = i2c->write(I2C_add,data,n+1);  // send n bytes of data
+  
+    return error;      
+}
+
+// *****************************************************************************
+//   MAX44009_read_register(char, char, char *)  reads single byte from MAX44009
+//                       char   I2C address
+//                       char   MAX44009 register address
+//                       char * data vector for read bytes to be stored in 
+//   returns                    0 on success, 1 on fail 
+// *****************************************************************************
+
+int MAX44009_read_register(I2C *i2c, char I2C_add, char reg_add, char *bytes){
+    int error;
+    error = i2c->write(I2C_add,&reg_add,1,1); 
+    if(error)return error;   
+    error = i2c->read(I2C_add,bytes,1);  
+    //if(DEBUG)db.printf("rr e[%d]\r\n",error);
+    return error; 
+}
+
+
+// *****************************************************************************
+//   MAX44009_read_lux_register(char, char, char *, int)  reads lux value bytes from MAX44009
+//                       char   I2C address
+//                       char   MAX44009 register address
+//                       char * data vector for read bytes to be stored in 
+//   returns                    0 on success, 1 on fail 
+// *****************************************************************************
+
+int MAX44009_read_lux_register(I2C *i2c, char I2C_add, char reg_add, char *bytes){
+    int error;
+    
+    error = i2c->write(I2C_add, &reg_add, 1, 1); 
+    if(error)return error;   
+    error = i2c->read(I2C_add, bytes, 1, true);
+    if(error)return error; 
+    
+    reg_add += 1;       // increment register address
+    error = i2c->write(I2C_add, &reg_add, 1, 1); //?
+    if(error)return error;   
+    error = i2c->read(I2C_add, bytes + 1, 1);       // bytes + 1; &bytes[1]
+      
+    //if(DEBUG)db.printf("rr e[%d]\r\n",error);
+    return error; 
+}
+
+
+// *****************************************************************************
+// convert_temperature(char)    sends convert command to MAX44009 device
+//                     char     I2C address
+// *****************************************************************************
+
+//void convert_temperature(I2C *i2c, char I2C_add){   // set convert bit to start conversion
+//
+//    char data[2];  
+//    
+//    //read ADC_SETUP register 0x14
+//    MAX44009_read_register(i2c, I2C_add, MAX44009_ADC_SETUP,data,1);       
+//
+//    //mask convert register value with 0x01 and write back register 0x14      
+//    MAX44009_write_register(i2c, I2C_add, MAX44009_ADC_SETUP, data[0]|0x01);
+//}
+
+//******************************************************************************
+// get_luxvalue(char)       read lux value from MAX44009 device register
+//                 char     I2C address
+// returns                  LuxResponse luxValue = light intensity in lux 
+//                          status = register read result
+//******************************************************************************
+
+LuxResponse get_luxvalue(I2C *i2c, char I2C_add){
+    char data[2];       // 2 bytes of raw Lux Register 
+    double lux;
+//    int count;
+    
+    // Read lux value, 2 bytes 
+    int error = MAX44009_read_lux_register(i2c, I2C_add, MAX44009_LUX_HI, data);     
+    
+    //calculate lux from data     
+//    count = (int)(data[0]*256 + data[1]);
+//    if (count >= 32768)count = count - 65536;     // 2s comp
+//    T = (double)count*0.005; 
+    
+    int exponent;
+    int mantissa;
+    exponent = int(data[0] >> 4);
+    mantissa = int(data[0] << 4) + int(data[1]);
+    lux = 0.045 * mantissa * pow((double)2, exponent);
+    
+    
+    LuxResponse resp;
+    resp.luxValue = lux;
+    resp.status = error; // 1 for nack/error. 0 for ack/success
+    return resp;  
+}
+