Diff: veml7700.cpp

Revision:

1:d6eb62dc0a1e

Parent:

0:e71d3ecdd257

--- a/veml7700.cpp	Tue Sep 10 11:11:19 2019 +0000
+++ b/veml7700.cpp	Tue Sep 10 13:33:10 2019 +0000
@@ -11,6 +11,7 @@
  * version 0.30  : start with error reporting 
  * version 0.34  : correction  
  * version 0.46  :  corrections for correct working , more methods added 
+ * version 0.50  : added readout in lux 
  * This file make part of the PeriperalDevice package see repository  
  * https://github.com/wimbeaumont/PeripheralDevices
  *
@@ -20,7 +21,7 @@
  *
  **/
 
-#define VERSION_VEML7700_SRC "0.49"
+#define VERSION_VEML7700_SRC "0.52"
 
 namespace VEML7700_CONST {
 // the VEML7700 support only 1 I2C address 
@@ -60,7 +61,9 @@
 u16 IntTSets[NrIntT]={ 0b1100,0b1000,0b0000,0b0001,0b0010,0b0011 };
 int IntTs[NrIntT] = { 25 ,50,100,200,400, 800 };
    
-
+const float luxref=.0576  ; // lux per bit for gain = 1 and IT =100 ms 
+const int RefIntT= 100;
+// min resolution gain =2  IT =800  , 0.0036 (als ch) 
 // R1 and R2 are 16 words  value 
 // bit mask R3 and values 
 const u16 RESERVED_BIT_MSK_POW_SET =  0xFFF8; // these bits should be 0  so use inverse with AND 
@@ -257,6 +260,22 @@
 u16 VEML7700::get_white_ch_bits(void){
     return read_cmd(WHITE );
 }
+
+
+float VEML7700::get_lux(bool ALSreg , bool verify_reg ) { 
+ u16 reg= ALSreg ?  ALS: WHITE;
+ u16 res = read_cmd(reg); 
+ if ( verify_reg ) {
+    reg= ALS_CONF_0;
+    reg =read_cmd(reg); 
+    (void) decodeIntTbits( reg,IntTnr  ); // just set this correct 
+    (void) decodeIntTbits( reg,gain_nr  ); // just set gain_nr correct 
+ }
+    
+ return (float)res *luxref / gains[gain_nr]*RefIntT   /(float) IntTs[IntTnr] ;
+}
+
+
 // below are not necessay but useful fpr debugging 
 u16 VEML7700::get_bits(u16 regvalue,   u16 lsb ,u16 bsize ) {
     u16 mask = 1; 
@@ -270,34 +289,43 @@
 }   
 
 float VEML7700::decodeGainBits( u16 gb) {
-    int g_nr ; float rv=0;
+    int dummy;
+    return decodeGainBits( gb, dummy ) ;
+}
+
+float VEML7700::decodeGainBits( u16 gb, int& g_nr) {
+    // this function doesn't set the gain_nr as it can be used for checking only 
     for ( g_nr = 0; g_nr < NrGains; g_nr++ ){
         if ( gb == GainSets[g_nr] ) { break;}                
     }
-    if( g_nr  < NrGains) { rv = gains[gain_nr];};
-    // else not valid gain setting , return 0 
-    return rv;
+    if( g_nr  >=  NrGains) { g_nr = NrGains-1;};
+    return gains[g_nr];
 }
 
-int VEML7700::decodeIntTbits( u16 ib ) {
-        int In_nr, rv=0;
+int VEML7700::decodeIntTbits( u16 ib) {
+    int dummy;
+    return decodeIntTbits(  ib,dummy );
+}
+
+int VEML7700::decodeIntTbits( u16 ib, int &In_nr ) {
+        // this function doesn't set the IntTnr as it can be used for checking only 
         for ( In_nr= 0;In_nr < NrIntT  ;In_nr++){
             if( ib == IntTSets[In_nr] ){ break;}            
          }
-         if ( In_nr <  NrIntT) { rv =IntTs[In_nr]; };
-            //else  not valid Integration bit code  return 0 
-         return rv ;
+         if ( In_nr >=  NrIntT) { In_nr= NrIntT-1;  };
+         return IntTs[In_nr];
 }
 
-void VEML7700::decode_Reg0(  bool& sd ,bool& ie, u16& pers_protect,int& IntT, float& gain  ) {
+u16 VEML7700::decode_Reg0(  bool& sd ,bool& ie, u16& pers_protect,int& IntT, float& gain  ) {
     u16 reg= read_cmd(ALS_CONF_0);
     u16 res= get_bits(reg, ALS_SD_LSB , ALS_SD_SIZE ) ;
-    sd = reg ? false : true;
+    sd = res ? false : true;
     res= get_bits(reg,ALS_INT_EN_LSB , ALS_INT_EN_SIZE ) ;
-    ie = reg ? false : true;
+    ie = res ? false : true;
     pers_protect= get_bits(reg,ALS_PERS_LSB , ALS_PERS_SIZE ) ;
     res= get_bits(reg,ALS_IT_LSB , ALS_IT_SIZE ) ;
     IntT=decodeIntTbits(res);
     res= get_bits(reg,ALS_GAIN_LSB , ALS_GAIN_SIZE ) ; 
     gain=decodeGainBits(res);
+    return reg;
 }