1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
#include "sensorAltimeter.hpp"
AltimeterSensor::AltimeterSensor(std::string I2C_FILE_in) {
I2C_FILE = I2C_FILE_in;
deviceAddress = 0x60;
}
//Startup routine copied from Adafruit library, as is most of the data getting methods
//Adaptation is largely editing for readability and porting from Adafruit_I2C to BBB I2C (sensorI2C.hpp implementation)
bool AltimeterSensor::init() {
// Vehicle *vehicle = (Vehicle *) data;
// // Do Stuff
// data = (void*) vehicle;
//Pass file string from parent to setup function, actual I2C bus gets stored internally.
setupI2C(I2C_FILE);
// Check a register with a hard-coded value to see if comms are working
uint8_t whoami = readSingleRegister(MPL3115A2_WHOAMI);
if (whoami != 0xC4) {
fprintf(stderr, "MPL INITIALIZATION DID NOT PASS WHOAMI DEVICE CHECK!, got: %X, expected: 0xC4\n", whoami);
return false;
}
//Send device dedicated reset byte to CTRL1 Register
writeRegister(MPL3115A2_CTRL_REG1, MPL3115A2_CTRL_REG1_RST);
//Wait for reset to wipe its way through device and reset appropriate bit of CTRL1 Register
while (readSingleRegister(MPL3115A2_CTRL_REG1) & MPL3115A2_CTRL_REG1_RST);
//Set oversampling (?) and altitude mode by default
currentMode = MPL3115A2_ALTIMETER;
ctrl_reg1.reg = MPL3115A2_CTRL_REG1_OS128 | MPL3115A2_CTRL_REG1_ALT;
writeRegister(MPL3115A2_CTRL_REG1, ctrl_reg1.reg);
//Configure data return types, I don't really understand this chunk but Adafruit does it this way so we will too I guess
writeRegister(MPL3115A2_PT_DATA_CFG, MPL3115A2_PT_DATA_CFG_TDEFE |
MPL3115A2_PT_DATA_CFG_PDEFE |
MPL3115A2_PT_DATA_CFG_DREM);
return true;
}
//EXPECTED THAT USER WILL NEVER SET MODE TO PRESSURE AFTER INITIAL CONFIGURATION
void AltimeterSensor::setMode(mpl3115a2_mode_t mode) {
ctrl_reg1.reg = readSingleRegister(MPL3115A2_CTRL_REG1);
ctrl_reg1.bit.ALT = mode;
writeRegister(MPL3115A2_CTRL_REG1, ctrl_reg1.reg);
currentMode = mode;
}
double AltimeterSensor::getAltitude() {
//Request new data reading
requestOneShotReading();
//If new data is available, read it and store it to internal fields
if (isNewDataAvailable()) {
//Logger flag here for new data?
updateCurrentDataBuffer();
}
//Return internal field, whether updated or not
return internalAltitude;
}
double AltimeterSensor::getTemperature() {
//Request new data reading
requestOneShotReading();
//If new data is available, read it and store it to internal fields
if (isNewDataAvailable()) {
//Logger flag here for new data?
updateCurrentDataBuffer();
}
//Return internal field, whether updated or not
return internalTemperature;
}
void AltimeterSensor::requestOneShotReading() {
//Request current status of oneshot reading
ctrl_reg1.reg = readSingleRegister(MPL3115A2_CTRL_REG1);
//If oneshot is complete, proc a new one; if it isn't, do nothing.
//THIS PRODUCES DUPLICATE DATA IF READING REQUESTS FROM BB DON'T LINE UP WITH READING COMPLETION ON SENSOR.
if (!ctrl_reg1.bit.OST) {
// initiate one-shot measurement
ctrl_reg1.bit.OST = 1;
writeRegister(MPL3115A2_CTRL_REG1, ctrl_reg1.reg);
}
}
bool AltimeterSensor::isNewDataAvailable() {
//Returns PTDR bit of status register, 1 if new data for Temp OR Alt/Pres is available
//There *are* registers available for exclusively temperature *or* pressure/altitude, but
//for simplicity's sake we'll use the combined one for now.
return ((readSingleRegister(MPL3115A2_REGISTER_STATUS) & MPL3115A2_REGISTER_STATUS_PTDR) != 0);
}
//Adafruit returns specific field based on input parameter, this method updates all internal fields at once instead
void AltimeterSensor::updateCurrentDataBuffer() {
uint8_t buffer[5] = {MPL3115A2_REGISTER_PRESSURE_MSB, 0, 0, 0, 0};
readMultipleRegisters(MPL3115A2_REGISTER_PRESSURE_MSB, 5);
//Pressure is no longer used, assumed rocket is only logging altitude
// uint32_t pressure;
// pressure = uint32_t(buffer[0]) << 16 | uint32_t(buffer[1]) << 8 |
// uint32_t(buffer[2]);
// return double(pressure) / 6400.0;
//Altitude Conversion
int32_t alt;
alt = uint32_t(buffer[0]) << 24 | uint32_t(buffer[1]) << 16 |
uint32_t(buffer[2]) << 8;
internalAltitude = double(alt) / 65536.0;
int16_t t;
t = uint16_t(buffer[3]) << 8 | uint16_t(buffer[4]);
internalTemperature = double(t) / 256.0;
}
|
