Rodolphe Fleury / GPS_I2C_astek

astek

GPS_I2C.cpp@0:f4c7ece483fe, 2019-12-27 (annotated)

Committer:
RoddyRod
Date:
Fri Dec 27 15:32:37 2019 +0000
Revision:
0:f4c7ece483fe
fsabatier;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
RoddyRod 0:f4c7ece483fe 1 #include "GPS_I2C.h"
RoddyRod 0:f4c7ece483fe 2
RoddyRod 0:f4c7ece483fe 3 GPS_I2C::GPS_I2C(PinName sda, PinName scl, uint32_t freq)
RoddyRod 0:f4c7ece483fe 4 : _i2c(sda, scl), _freq(freq)
RoddyRod 0:f4c7ece483fe 5 {
RoddyRod 0:f4c7ece483fe 6 _i2c.frequency(_freq);
RoddyRod 0:f4c7ece483fe 7 }
RoddyRod 0:f4c7ece483fe 8
RoddyRod 0:f4c7ece483fe 9 GPS_I2C::~GPS_I2C() {}
RoddyRod 0:f4c7ece483fe 10 /*****************************************************/
RoddyRod 0:f4c7ece483fe 11 bool GPS_I2C::begin()
RoddyRod 0:f4c7ece483fe 12 {
RoddyRod 0:f4c7ece483fe 13 int ack;
RoddyRod 0:f4c7ece483fe 14
RoddyRod 0:f4c7ece483fe 15 _head = 0;
RoddyRod 0:f4c7ece483fe 16 _tail = 0;
RoddyRod 0:f4c7ece483fe 17
RoddyRod 0:f4c7ece483fe 18 ack = _i2c.read(MT333x_ADDR << 1, (char*)gpsData, 1);
RoddyRod 0:f4c7ece483fe 19 //Verify if module is connected
RoddyRod 0:f4c7ece483fe 20 if( ack != 0 ) return false;
RoddyRod 0:f4c7ece483fe 21 else return true;
RoddyRod 0:f4c7ece483fe 22 }
RoddyRod 0:f4c7ece483fe 23
RoddyRod 0:f4c7ece483fe 24 void GPS_I2C::check()
RoddyRod 0:f4c7ece483fe 25 {
RoddyRod 0:f4c7ece483fe 26 uint8_t packetData[MAX_PACKET_SIZE];
RoddyRod 0:f4c7ece483fe 27
RoddyRod 0:f4c7ece483fe 28 for (uint8_t x = 0 ; x < MAX_PACKET_SIZE ; x++) {
RoddyRod 0:f4c7ece483fe 29 packetData[x] = 0x0A; //Fill with garbage byte
RoddyRod 0:f4c7ece483fe 30 }
RoddyRod 0:f4c7ece483fe 31
RoddyRod 0:f4c7ece483fe 32 _i2c.read(MT333x_ADDR << 1, ((char*)packetData), MAX_PACKET_SIZE);
RoddyRod 0:f4c7ece483fe 33
RoddyRod 0:f4c7ece483fe 34 for (uint8_t x = 0 ; x < MAX_PACKET_SIZE ; x++) {
RoddyRod 0:f4c7ece483fe 35 if (packetData[x] != 0x0A) {
RoddyRod 0:f4c7ece483fe 36 gpsData[_head++] = packetData[x];
RoddyRod 0:f4c7ece483fe 37 if (_head == MAX_PACKET_SIZE) _head = 0; //Wrap variable
RoddyRod 0:f4c7ece483fe 38 }
RoddyRod 0:f4c7ece483fe 39 }
RoddyRod 0:f4c7ece483fe 40 }
RoddyRod 0:f4c7ece483fe 41
RoddyRod 0:f4c7ece483fe 42 uint8_t GPS_I2C::available()
RoddyRod 0:f4c7ece483fe 43 {
RoddyRod 0:f4c7ece483fe 44 //If tail=head then no new data is available in the local buffer
RoddyRod 0:f4c7ece483fe 45 //So now check to see if the module has anything new in its buffer
RoddyRod 0:f4c7ece483fe 46 if (_tail == _head) {
RoddyRod 0:f4c7ece483fe 47 check(); //Check to module to see if new I2C bytes are available
RoddyRod 0:f4c7ece483fe 48 }
RoddyRod 0:f4c7ece483fe 49
RoddyRod 0:f4c7ece483fe 50 //Return new data count
RoddyRod 0:f4c7ece483fe 51 if (_head > _tail) return (_head - _tail);
RoddyRod 0:f4c7ece483fe 52 if (_tail > _head) return (MAX_PACKET_SIZE - _tail + _head);
RoddyRod 0:f4c7ece483fe 53 return (0); //No data available
RoddyRod 0:f4c7ece483fe 54 }
RoddyRod 0:f4c7ece483fe 55 uint8_t GPS_I2C::read()
RoddyRod 0:f4c7ece483fe 56 {
RoddyRod 0:f4c7ece483fe 57 if (_tail != _head) {
RoddyRod 0:f4c7ece483fe 58 uint8_t datum = gpsData[_tail++];
RoddyRod 0:f4c7ece483fe 59 if (_tail == MAX_PACKET_SIZE) _tail = 0; //Wrap variable
RoddyRod 0:f4c7ece483fe 60 return (datum);
RoddyRod 0:f4c7ece483fe 61 } else
RoddyRod 0:f4c7ece483fe 62 return (0); //No new data
RoddyRod 0:f4c7ece483fe 63 }