att160826.h

00001 #include "pca9548.h"
00002 #include "sfh7779.h"
00003 
00004 #define SENSORS_PER_STRIP   8
00005 
00006 typedef struct {
00007     bool                    present;
00008     sfh7779_measurements_t  sample;
00009 } sfh7779_data_t;
00010 
00011 typedef struct {
00012     sfh7779_data_t  sensor[SENSORS_PER_STRIP];
00013 } att160826_data_t;
00014 
00015 class ATT160826
00016 {
00017 public:
00018     /**
00019     * Constructor
00020     *
00021     * @param i2c I2C class servicing the strip
00022     * @param addr_3bit address of the strip (A0-A2 of I2C multiplexer)
00023     *          Valid values are 0-7
00024     * @param reset optional DigitalOut class that resets the strip
00025     *          Not needed if hardware reset is not used or if reset 
00026     *          is not managed by the class.
00027     */
00028     ATT160826(I2C * i2c, uint8_t addr_3bit, DigitalOut * reset = NULL) {
00029         _pca9548 = new PCA9548(i2c, addr_3bit, reset);
00030         for (int x = 0; x < SENSORS_PER_STRIP; x++) {
00031             _sfh7779[x] = new SFH7779(i2c);
00032         }
00033     }
00034 
00035     /**
00036     * Destructor
00037     */
00038     ~ATT160826() {
00039         if (_pca9548) {
00040             delete _pca9548;
00041         }
00042         for (int x = 0; x < SENSORS_PER_STRIP; x++) {
00043             if (_sfh7779[x]) {
00044                 delete _sfh7779[x];
00045             }
00046         }
00047     }
00048 
00049     /**
00050     * Sample all sensors on the strip (proximity, visual ambient light, and infrared ambient light).
00051     * Sensors are all activated, sampled, and then placed in standby mode to conserve power consumption.
00052     *
00053     * @param att160826_data pointer to a buffer which will be filled with a sensor data
00054     *
00055     * @returns true if successfull
00056     */
00057     bool scan(att160826_data_t * att160826_data) {
00058         
00059         // Clear all previous measurements before starting the scan
00060         memset(att160826_data, 0, sizeof(att160826_data_t));
00061         
00062         if (_pca9548) {
00063             // Enable all sensors
00064             for (int x = 0; x < SENSORS_PER_STRIP; x++) {
00065                 int channel_idx = x;
00066                 bool ok = _pca9548->select_channel(channel_idx)
00067                           && _sfh7779[x]                            
00068                           && _sfh7779[x]->enable();
00069                 att160826_data->sensor[x].present = ok;
00070             }
00071             
00072             // Collect data from all sensors (throw away 1st sample and keep 2nd)
00073             for (int y = 0; y < 1; y++) {
00074                 for (int x = 0; x < SENSORS_PER_STRIP; x++) {
00075                     int channel_idx = x;
00076                     if (att160826_data->sensor[x].present &&
00077                         _pca9548->select_channel(channel_idx)) {
00078                         _sfh7779[x]->read(&(att160826_data->sensor[x].sample), 500);
00079                     }
00080                 }
00081             }
00082             /*
00083             // Disable all sensors
00084             for (int x = 0; x < SENSORS_PER_STRIP; x++) {
00085                 int channel_idx = x;
00086                 bool ok = _pca9548->select_channel(channel_idx)
00087                           && _sfh7779[x]->disable();
00088             }
00089             */
00090             // Disconnect all sensors from the I2C bus
00091             _pca9548->reset();
00092         }
00093         
00094         return true;
00095     }
00096 
00097 protected:
00098     PCA9548 *       _pca9548;
00099     SFH7779 *       _sfh7779[SENSORS_PER_STRIP];
00100 };