Revision 2:82782c73251e, committed 2016-07-26

Comitter:

loopsva

Date:

Tue Jul 26 19:52:23 2016 +0000

Parent:

1:fd536ebc7eaf

Commit message:

Fixes bug in DISCO_F746NG when reading MLX9062x EEPROM. The F746 has a 255 byte I2C limit. Any transfer larger, the buffer returns all 0xff. So, the MLX's EEPROM needs to be read 1 + 255 bytes in order to get all 256. A compiler flag is used.

Changed in this revision

--- a/MLX90620.cpp	Thu Jul 21 23:09:24 2016 +0000
+++ b/MLX90620.cpp	Tue Jul 26 19:52:23 2016 +0000
@@ -24,7 +24,7 @@
     _i2c.stop();                                        //initialize with a stop
     mlxDev = MLXtype;                                   //user select device 620 or 621
 }
-
+   
 //--------------------------------------------------------------------------------------------------------------------------------------//
 //copy contents of EEPROM inside the MLX9062x into a local buffer.  Data is used for lookup tables and parameters
 
@@ -37,20 +37,20 @@
     
     //clear out buffer first
     for(int i = 0; i < 256; i++) Pntr.MLXEEbuf[i] = 0;  //clear out entire EEMPROM buffer
-    
-    //load the entire EEPROM
-    Pntr.MLXEEbuf[0] = 0;                                       //start at address 0 of EEPROM
+
+//the following code addition of a 1 byte I2C fetch is due to a bug in the F746NG which can only transfer 255 bytes at a time.  grrr!!!....
+#if defined(TARGET_DISCO_F746NG)
+#warning "TARGET_DISCO_F746NG i2c bug, 255 byte limit!!!"
+    Pntr.MLXEEbuf[0] = 255;
+    if(!_i2c.write(MLX_EEPADDR, Pntr.MLXEEbuf, 1, true)) {
+        _i2c.read((MLX_EEPADDR + 1), Pntr.MLXEEbuf, 1, false);
+        Pntr.MLXEEbuf[255] = Pntr.MLXEEbuf[0];
+        Pntr.MLXEEbuf[0] = 0;
+        _i2c.write(MLX_EEPADDR, Pntr.MLXEEbuf, 1, true);
+        _i2c.read((MLX_EEPADDR + 1), Pntr.MLXEEbuf, 255, false); //s/b 256 if F746NG bug wasn't there
+#else
     if(!_i2c.write(MLX_EEPADDR, Pntr.MLXEEbuf, 1, true)) {      //send command, 0 returned is ok
-
-#ifdef MLX_EEP_EASY_LOAD
-        _i2c.read((MLX_EEPADDR + 1), Pntr.MLXEEbuf, 256);//**** this command does not work with the KL25Z and v63 of mbed.lbr !!!!
-#else
-        _i2c.start();
-        _i2c.write(MLX_EEPADDR + 1);
-        for(int i = 0; i < 256; i++) {
-            Pntr.MLXEEbuf[i] = _i2c.read(1);
-        }
-        _i2c.stop();
+        _i2c.read((MLX_EEPADDR + 1), Pntr.MLXEEbuf, 256, false);
 #endif
 
     } else {
@@ -658,3 +658,4 @@
 }
 
 
+