VL6180x.cpp

00001 /******************************************************************************
00002  * SFE_VL6180x.cpp
00003  * Library for VL6180x time of flight range finder.
00004  * Casey Kuhns @ SparkFun Electronics
00005  * 10/29/2014
00006  * https://github.com/sparkfun/
00007  * 
00008  * The VL6180x by ST micro is a time of flight range finder that
00009  * uses pulsed IR light to determine distances from object at close
00010  * range.  The average range of a sensor is between 0-200mm
00011  * 
00012  * In this file are the functions in the VL6180x class
00013  * 
00014  * Resources:
00015  * This library uses the Arduino Wire.h to complete I2C transactions.
00016  * 
00017  * Development environment specifics:
00018  *  IDE: Arduino 1.0.5
00019  *  Hardware Platform: Arduino Pro 3.3V/8MHz
00020  *  VL6180x Breakout Version: 1.0
00021  * 
00022  * 
00023  * This code is beerware. If you see me (or any other SparkFun employee) at the
00024  * local pub, and you've found our code helpful, please buy us a round!
00025  * 
00026  * Distributed as-is; no warranty is given.
00027  ******************************************************************************/
00028 
00029 
00030 #include "VL6180x.h"
00031 
00032 VL6180x::VL6180x(PinName sda, PinName scl, uint8_t addr) : m_i2c(sda, scl), m_addr(addr) {}
00033 int VL6180x::VL6180xInit(void){
00034   uint8_t data; //for temp data storage
00035 
00036   data = VL6180x_getRegister(VL6180X_SYSTEM_FRESH_OUT_OF_RESET);
00037   wait_ms(50);
00038   if(data != 1) return VL6180x_FAILURE_RESET;
00039 
00040   //Required by datasheet
00041   //http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00122600.pdf
00042   VL6180x_setRegister(0x0207, 0x01);
00043   VL6180x_setRegister(0x0208, 0x01);
00044   VL6180x_setRegister(0x0096, 0x00);
00045   VL6180x_setRegister(0x0097, 0xfd);
00046   VL6180x_setRegister(0x00e3, 0x00);
00047   VL6180x_setRegister(0x00e4, 0x04);
00048   VL6180x_setRegister(0x00e5, 0x02);
00049   VL6180x_setRegister(0x00e6, 0x01);
00050   VL6180x_setRegister(0x00e7, 0x03);
00051   VL6180x_setRegister(0x00f5, 0x02);
00052   VL6180x_setRegister(0x00d9, 0x05);
00053   VL6180x_setRegister(0x00db, 0xce);
00054   VL6180x_setRegister(0x00dc, 0x03);
00055   VL6180x_setRegister(0x00dd, 0xf8);
00056   VL6180x_setRegister(0x009f, 0x00);
00057   VL6180x_setRegister(0x00a3, 0x3c);
00058   VL6180x_setRegister(0x00b7, 0x00);
00059   VL6180x_setRegister(0x00bb, 0x3c);
00060   VL6180x_setRegister(0x00b2, 0x09);
00061   VL6180x_setRegister(0x00ca, 0x09);  
00062   VL6180x_setRegister(0x0198, 0x01);
00063   VL6180x_setRegister(0x01b0, 0x17);
00064   VL6180x_setRegister(0x01ad, 0x00);
00065   VL6180x_setRegister(0x00ff, 0x05);
00066   VL6180x_setRegister(0x0100, 0x05);
00067   VL6180x_setRegister(0x0199, 0x05);
00068   VL6180x_setRegister(0x01a6, 0x1b);
00069   VL6180x_setRegister(0x01ac, 0x3e);
00070   VL6180x_setRegister(0x01a7, 0x1f);
00071   VL6180x_setRegister(0x0030, 0x00);
00072 
00073   return 0;
00074 }
00075 VL6180x::~VL6180x(void) {
00076 };
00077 
00078 void VL6180x::VL6180xDefautSettings(void){
00079   //Recommended settings from datasheet
00080   //http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00122600.pdf
00081 
00082   //Enable Interrupts on Conversion Complete (any source)
00083   VL6180x_setRegister(VL6180X_SYSTEM_INTERRUPT_CONFIG_GPIO, (4 << 3)|(4) ); // Set GPIO1 high when sample complete
00084 
00085 
00086   VL6180x_setRegister(VL6180X_SYSTEM_MODE_GPIO1, 0x10); // Set GPIO1 high when sample complete
00087   VL6180x_setRegister(VL6180X_READOUT_AVERAGING_SAMPLE_PERIOD, 0x30); //Set Avg sample period
00088   VL6180x_setRegister(VL6180X_SYSALS_ANALOGUE_GAIN, 0x46); // Set the ALS gain
00089   VL6180x_setRegister(VL6180X_SYSRANGE_VHV_REPEAT_RATE, 0xFF); // Set auto calibration period (Max = 255)/(OFF = 0)
00090   VL6180x_setRegister(VL6180X_SYSALS_INTEGRATION_PERIOD, 0x63); // Set ALS integration time to 100ms
00091   VL6180x_setRegister(VL6180X_SYSRANGE_VHV_RECALIBRATE, 0x01); // perform a single temperature calibration
00092   //Optional settings from datasheet
00093   //http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00122600.pdf
00094   VL6180x_setRegister(VL6180X_SYSRANGE_INTERMEASUREMENT_PERIOD, 0x09); // Set default ranging inter-measurement period to 100ms
00095   VL6180x_setRegister(VL6180X_SYSALS_INTERMEASUREMENT_PERIOD, 0x0A); // Set default ALS inter-measurement period to 100ms
00096   VL6180x_setRegister(VL6180X_SYSTEM_INTERRUPT_CONFIG_GPIO, 0x24); // Configures interrupt on ‘New Sample Ready threshold event’ 
00097   //Additional settings defaults from community
00098   VL6180x_setRegister(VL6180X_SYSRANGE_MAX_CONVERGENCE_TIME, 0x32);
00099   VL6180x_setRegister(VL6180X_SYSRANGE_RANGE_CHECK_ENABLES, 0x10 | 0x01);
00100   VL6180x_setRegister16bit(VL6180X_SYSRANGE_EARLY_CONVERGENCE_ESTIMATE, 0x7B );
00101   VL6180x_setRegister16bit(VL6180X_SYSALS_INTEGRATION_PERIOD, 0x64);
00102 
00103   VL6180x_setRegister(VL6180X_READOUT_AVERAGING_SAMPLE_PERIOD,0x30);
00104   VL6180x_setRegister(VL6180X_SYSALS_ANALOGUE_GAIN,0x40);
00105   VL6180x_setRegister(VL6180X_FIRMWARE_RESULT_SCALER,0x01);
00106 }
00107 void VL6180x::getIdentification(struct VL6180xIdentification *temp){
00108 
00109   temp->idModel =  VL6180x_getRegister(VL6180X_IDENTIFICATION_MODEL_ID);
00110   temp->idModelRevMajor = VL6180x_getRegister(VL6180X_IDENTIFICATION_MODEL_REV_MAJOR);
00111   temp->idModelRevMinor = VL6180x_getRegister(VL6180X_IDENTIFICATION_MODEL_REV_MINOR);
00112   temp->idModuleRevMajor = VL6180x_getRegister(VL6180X_IDENTIFICATION_MODULE_REV_MAJOR);
00113   temp->idModuleRevMinor = VL6180x_getRegister(VL6180X_IDENTIFICATION_MODULE_REV_MINOR);
00114 
00115   temp->idDate = VL6180x_getRegister16bit(VL6180X_IDENTIFICATION_DATE);
00116   temp->idTime = VL6180x_getRegister16bit(VL6180X_IDENTIFICATION_TIME);
00117 }
00118 
00119 
00120 uint8_t VL6180x::changeAddress(uint8_t old_address, uint8_t new_address){
00121   
00122   //NOTICE:  IT APPEARS THAT CHANGING THE ADDRESS IS NOT STORED IN NON-VOLATILE MEMORY
00123   // POWER CYCLING THE DEVICE REVERTS ADDRESS BACK TO 0X29
00124  
00125   if( old_address == new_address) return old_address;
00126   if( new_address > 127) return old_address;
00127    
00128    VL6180x_setRegister(VL6180X_I2C_SLAVE_DEVICE_ADDRESS, new_address);
00129    
00130    return VL6180x_getRegister(VL6180X_I2C_SLAVE_DEVICE_ADDRESS); 
00131 }
00132   
00133 
00134 
00135 uint8_t VL6180x::getDistance() {
00136   uint8_t distance;
00137   VL6180x_setRegister(VL6180X_SYSRANGE_START, 0x01); //Start Single shot mode
00138   wait_ms(10);
00139   distance = VL6180x_getRegister(VL6180X_RESULT_RANGE_VAL);
00140   VL6180x_setRegister(VL6180X_SYSTEM_INTERRUPT_CLEAR, 0x07);
00141   return distance;
00142 }
00143 
00144 float VL6180x::getAmbientLight(vl6180x_als_gain VL6180X_ALS_GAIN)
00145 {
00146   //First load in Gain we are using, do it everytime incase someone changes it on us.
00147   //Note: Upper nibble shoudl be set to 0x4 i.e. for ALS gain of 1.0 write 0x46
00148   VL6180x_setRegister(VL6180X_SYSALS_ANALOGUE_GAIN, (0x40 | VL6180X_ALS_GAIN)); // Set the ALS gain
00149 
00150   //Start ALS Measurement 
00151   VL6180x_setRegister(VL6180X_SYSALS_START, 0x01);
00152 
00153     wait_ms(100); //give it time... 
00154 
00155   VL6180x_setRegister(VL6180X_SYSTEM_INTERRUPT_CLEAR, 0x07);
00156 
00157   //Retrieve the Raw ALS value from the sensoe
00158   unsigned int alsRaw = VL6180x_getRegister16bit(VL6180X_RESULT_ALS_VAL);
00159   
00160   //Get Integration Period for calculation, we do this everytime incase someone changes it on us.
00161   unsigned int alsIntegrationPeriodRaw = VL6180x_getRegister16bit(VL6180X_SYSALS_INTEGRATION_PERIOD);
00162   
00163   float alsIntegrationPeriod = 100.0 / alsIntegrationPeriodRaw ;
00164 
00165   //Calculate actual LUX from Appnotes
00166 
00167   float alsGain = 0.0;
00168   
00169   switch (VL6180X_ALS_GAIN){
00170     case GAIN_20: alsGain = 20.0; break;
00171     case GAIN_10: alsGain = 10.32; break;
00172     case GAIN_5: alsGain = 5.21; break;
00173     case GAIN_2_5: alsGain = 2.60; break;
00174     case GAIN_1_67: alsGain = 1.72; break;
00175     case GAIN_1_25: alsGain = 1.28; break;
00176     case GAIN_1: alsGain = 1.01; break;
00177     case GAIN_40: alsGain = 40.0; break;
00178   }
00179 
00180 //Calculate LUX from formula in AppNotes
00181   
00182   float alsCalculated = (float)0.32 * ((float)alsRaw / alsGain) * alsIntegrationPeriod;
00183 
00184   return alsCalculated;
00185 }
00186 
00187 // --- Private Functions --- //
00188 
00189 uint8_t VL6180x::VL6180x_getRegister(uint16_t registerAddr)
00190 {
00191   uint8_t data;
00192   char data_write[2];
00193   char data_read[1];
00194   data_write[0] = (registerAddr >> 8) & 0xFF; //MSB of register address 
00195   data_write[1] = registerAddr & 0xFF; //LSB of register address 
00196   m_i2c.write(m_addr, data_write, 2,0); 
00197   m_i2c.read(m_addr,data_read,1,1);
00198   //Read Data from selected register
00199   data=data_read[0];
00200   return data;
00201 }
00202 
00203 uint16_t VL6180x::VL6180x_getRegister16bit(uint16_t registerAddr)
00204 {
00205   uint8_t data_low;
00206   uint8_t data_high;
00207   uint16_t data;
00208 
00209   char data_write[2];
00210   char data_read[2];
00211   data_write[0] = (registerAddr >> 8) & 0xFF; //MSB of register address 
00212   data_write[1] = registerAddr & 0xFF; //LSB of register address 
00213   m_i2c.write(m_addr, data_write, 2,0); 
00214   m_i2c.read(m_addr,data_read,2,1);
00215   data_high = data_read[0]; //Read Data from selected register
00216   data_low = data_read[1]; //Read Data from selected register
00217   data = (data_high << 8)|data_low;
00218 
00219   return data;
00220 }
00221 
00222 void VL6180x::VL6180x_setRegister(uint16_t registerAddr, uint8_t data)
00223 {
00224     char data_write[3];
00225     data_write[0] = (registerAddr >> 8) & 0xFF; //MSB of register address 
00226     data_write[1] = registerAddr & 0xFF; //LSB of register address 
00227     data_write[2] = data & 0xFF; 
00228     m_i2c.write(m_addr, data_write, 3); 
00229 }
00230 
00231 void VL6180x::VL6180x_setRegister16bit(uint16_t registerAddr, uint16_t data)
00232 {
00233     char data_write[4];
00234     data_write[0] = (registerAddr >> 8) & 0xFF; //MSB of register address 
00235     data_write[1] = registerAddr & 0xFF; //LSB of register address 
00236     data_write[2] = (data >> 8) & 0xFF;
00237     data_write[3] = data & 0xFF; 
00238     m_i2c.write(m_addr, data_write, 4); 
00239 }