acc.cpp

00001 #include "acc.h"
00002 
00003 
00004 void acc_init(float duration, float threshold, float gap, float window){
00005     //acc = &connection;
00006     char durationByte, thresholdByte, gapByte, windowByte; 
00007     
00008     //convert the function parameters from their respective units to the appropriate byte values
00009     durationByte = duration / 0.625;
00010     thresholdByte = threshold / 0.00625;
00011     gapByte = gap / 1.25;
00012     windowByte = window / 1.25;
00013     
00014     //set the config constants
00015     char acc_config_dataFormat[2] = {0x31,0x0b}; //measurement range
00016     char acc_config_powerControl[2] = {0x2d,0x08};
00017     char acc_config_tapThreshold[2] = {0x1d,thresholdByte};
00018     char acc_config_tapDuration[2] = {0x21,durationByte};
00019     char acc_config_latentGap[2] = {0x22,gapByte};
00020     char acc_config_window[2] = {0x23,windowByte};
00021     char acc_config_enableAxis[2] = {0x2a,0x07};
00022     char acc_config_intEnable[2] = {0x2e,0x60};
00023     char acc_config_intMap[2] = {0x2f,0x60};
00024     
00025     //set the configuration
00026     connection.write(addr_acc, acc_config_dataFormat, 2); //full measurement range
00027     wait(.05);
00028     connection.write(addr_acc, acc_config_tapDuration, 2);
00029     wait(.05);
00030     connection.write(addr_acc, acc_config_tapThreshold, 2);
00031     wait(.05);
00032     connection.write(addr_acc, acc_config_latentGap, 2);
00033     wait(.05);
00034     connection.write(addr_acc, acc_config_window, 2);
00035     wait(.05);
00036     connection.write(addr_acc, acc_config_enableAxis, 2);
00037     wait(.05); 
00038     connection.write(addr_acc, acc_config_intEnable, 2);
00039     wait(.05);
00040     connection.write(addr_acc, acc_config_intMap, 2);
00041     wait(.05);
00042      connection.write(addr_acc, acc_config_powerControl, 2); // measure mode
00043     wait(.05);
00044 }
00045 
00046 char get_int_type(){
00047     char int_source_arr[2] = {0x30|0x80, 0x00};
00048     connection.write(addr_acc, int_source_arr, 1); //set up the connection for reading from int_source
00049     char acc_data[1];
00050     connection.read(addr_acc, acc_data, 1); //read the int_source byte
00051     //pc.printf("%x\t",acc_data[0]&0x60); //this was used for debugging
00052     if(acc_data[0] & 0x20) //if a double tap, return 2
00053         return 2;
00054     else if (acc_data[0] & 0x40) //if a single tap, return 1
00055         return 1;
00056     //this code should never be reached, but is included so that there is an appropriate exit path   
00057     return 0;
00058 }