Revision 3:a2effad05c99, committed 2017-05-04

Comitter:

j3

Date:

Thu May 04 23:44:48 2017 +0000

Parent:

2:0db1f3bec727

Child:

4:d1b50bd4065a

Commit message:

Added reading fifo mbr fx. Library requires algorithm to get heart rate or SpO2 readings.

Changed in this revision

--- a/MAX30101.cpp	Mon May 01 21:00:34 2017 +0000
+++ b/MAX30101.cpp	Thu May 04 23:44:48 2017 +0000
@@ -259,6 +259,60 @@
 }
 
 
+//*****************************************************************************     
+int32_t MAX30101::readFIFO(uint8_t numLeds, uint8_t *data, uint16_t &readBytes)
+{
+    int32_t result = -1;
+    
+    readBytes = 0;
+    
+    if((numLeds > 0) && (numLeds < 4))
+    {
+        //Get write pointer
+        result = readRegister(FIFO_WritePointer, m_fifoWritePtr);
+        if(result == 0)
+        {
+            //Get read pointer
+            result = readRegister(FIFO_ReadPointer, m_fifoReadPtr);
+            if(result == 0)
+            {
+                //Calculate num bytes to read
+                if(m_fifoWritePtr > m_fifoReadPtr)
+                {
+                    m_fifoNumBytes = ((m_fifoWritePtr - m_fifoReadPtr) * 
+                                      (BYTES_PER_CH * numLeds));
+                }
+                else
+                {
+                    m_fifoNumBytes = (((32 - m_fifoReadPtr) + m_fifoWritePtr) * 
+                                       (BYTES_PER_CH * numLeds));
+                }
+                
+                //temporary buffer for data
+                char local_data[m_fifoNumBytes];
+                local_data[0] = FIFO_DataRegister;
+                
+                //Set fifo data ptr
+                result = m_i2cBus.write(I2C_W_ADRS, local_data, 1, true);
+                if(result == 0)
+                {
+                    //read fifo
+                    result = m_i2cBus.read(I2C_R_ADRS, local_data,  m_fifoNumBytes);
+                    if(result == 0)
+                    {
+                        //move data to user buffer
+                        memcpy(data, local_data, m_fifoNumBytes);
+                        readBytes = m_fifoNumBytes;
+                    }
+                }
+            }
+        }
+    }
+    
+    return result;
+}
+
+
 //*****************************************************************************
 int32_t MAX30101::writeRegister(Registers_e reg, uint8_t value)
 {

--- a/MAX30101.h	Mon May 01 21:00:34 2017 +0000
+++ b/MAX30101.h	Thu May 04 23:44:48 2017 +0000
@@ -68,6 +68,10 @@
     static const uint8_t I2C_W_ADRS = 0xAE;
     ///8-bit read address
     static const uint8_t I2C_R_ADRS = 0xAF;
+    ///Max # Bytes in FIFO
+    static const uint16_t MAX_FIFO_BYTES = 288;
+    ///# of bytes per LED channel
+    static const uint8_t BYTES_PER_CH = 3;
     
     ///MAX30101 Register Map
     enum Registers_e
@@ -97,6 +101,14 @@
         PartID             = 0xFF
     };
     
+    ///MAX30101 Operational Modes
+    enum OpModes_e
+    {
+        HeartRateMode = 2,
+        SpO2Mode      = 3,
+        MultiLedMode  = 7
+    };
+    
     ///Interrupt Status/Enable BitField
     union InterruptBitField_u
     {
@@ -323,6 +335,17 @@
     * @return 0 on success, non 0 otherwise
     */
     int32_t getProxIntThreshold(uint8_t &data);
+    
+    /** 
+    * @brief Attempts to read numBytes of data from FIFO
+    *
+    * @param numLeds - Number of LED channels used; 0 < numLeds < 4
+    * @param data - pointer to buffer for holding read data
+    * @param[out] readBytes - number of bytes read from fifo
+    *
+    * @return 0 on success, non 0 otherwise
+    */
+    int32_t readFIFO(uint8_t numLeds, uint8_t *data, uint16_t &readBytes);
 
 protected:
 
@@ -345,6 +368,8 @@
 private:
 
     I2C m_i2cBus;
+    uint8_t m_fifoReadPtr, m_fifoWritePtr, m_fifoNumBytes;
+    
 
 };