test
Dependents: FM_integration_copy
Fork of MPL3115A2 by
MPL3115A2.cpp
- Committer:
- sophtware
- Date:
- 2014-04-01
- Revision:
- 0:beb43bc3d6d4
File content as of revision 0:beb43bc3d6d4:
#include "MPL3115A2.h" #include "mbed.h" #include "stdarg.h" // For debugOut use of the ... parameter and va_list MPL3115A2::MPL3115A2(I2C *i2c, Serial *pc) : _i2c(i2c), _debug(pc) { } // By default I set the sensor to altimeter mode. I inserted a 1ms pause // between each call to allow logic capture if needed. This give a small // gap between captures on the bus to make working with the data easier. void MPL3115A2::init() { setModeStandby(); wait_ms(1); setModeAltimeter(); wait_ms(1); setOversampleRate(7); wait_ms(1); enableEventFlags(); wait_ms(1); setModeActive(); wait_ms(1); } // This method wait for a specified amount of time for one of the data // ready flags to be set. You need to pass in the correct data ready // mask for this to work. See page 22 of the datasheet. int MPL3115A2::dataReady(const char mask) { int attempts = 0; while ((i2cRead(STATUS) & mask) == 0) { attempts++; if(attempts > MAX_DATA_READY_ATTEMPTS) return 0; // Failed wait_ms(1); } return 1; // Success } Altitude* MPL3115A2::readAltitude(Altitude* a) { // Force the sensor to take a new reading. toggleOneShot(); // Wait for the data to be ready. if (!pressureDataReady()) { debugOut("MPL3115A2::readAltitude: Sensor failed to generate an altitude reading in a reasonable time.\r\n"); // We leave the altitude object as is if we encounter an error. return a; } // Get the new data from the sensor. _i2c->start(); // Start if (_i2c->write(MPL3115A2_ADDRESS) != 1) // A write to device debugOut("MPL3115A2::readAltitude: Sensor failed to respond to write request at address 0x%X\r\n", MPL3115A2_ADDRESS); if (_i2c->write(OUT_P_MSB) != 1) // Register to read debugOut("MPL3115A2::readAltitude: Sensor at address 0x%X did not acknowledge register 0x%X\r\n", MPL3115A2_ADDRESS, OUT_P_MSB); // Write the data directly into our Altitude object. This object // takes care of converting the compressed data from the sensor, and // provides functions to get the data in various units. And it also // has a print function to output the data as a string. _i2c->read(MPL3115A2_ADDRESS, (*a), Altitude::size); a->setAltitude(); return a; } // See readAltitude for comments about this function. Pressure* MPL3115A2::readPressure(Pressure* p) { toggleOneShot(); if (!pressureDataReady()) { debugOut("MPL3115A2::readPressure: Sensor failed to generate a pressure reading in a reasonable time.\r\n"); return p; } _i2c->start(); if (_i2c->write(MPL3115A2_ADDRESS) != 1) debugOut("MPL3115A2::readPressure: Sensor failed to respond to write request at address 0x%X\r\n", MPL3115A2_ADDRESS); if (_i2c->write(OUT_P_MSB) != 1) debugOut("MPL3115A2::readPressure: Sensor at address 0x%X did not acknowledge register 0x%X\r\n", MPL3115A2_ADDRESS, OUT_P_MSB); _i2c->read(MPL3115A2_ADDRESS, (*p), Pressure::size); p->setPressure(); return p; } // See readAltitude for comments about this function. Temperature* MPL3115A2::readTemperature(Temperature* t) { toggleOneShot(); if (!temperatureDataReady()) { debugOut("MPL3115A2::readTemperature: Sensor failed to generate a temperature reading in a reasonable time.\r\n"); return t; } _i2c->start(); if (_i2c->write(MPL3115A2_ADDRESS) != 1) debugOut("MPL3115A2::readTemperature: Sensor failed to respond to write request at address 0x%X\r\n", MPL3115A2_ADDRESS); if (_i2c->write(OUT_T_MSB) != 1) debugOut("MPL3115A2::readTemperature: Sensor at address 0x%X did not acknowledge register 0x%X\r\n", MPL3115A2_ADDRESS, OUT_P_MSB); _i2c->read(MPL3115A2_ADDRESS, (*t), Temperature::size); t->setTemperature(); return t; } void MPL3115A2::setModeAltimeter() { setRegisterBit(CTRL_REG1, 0x80); // Set ALT bit } void MPL3115A2::setModeBarometer() { clearRegisterBit(CTRL_REG1, 0x80); // Clear ALT bit } void MPL3115A2::setModeStandby() { clearRegisterBit(CTRL_REG1, 0x01); // Clear SBYB bit for Standby mode } void MPL3115A2::setModeActive() { setRegisterBit(CTRL_REG1, 0x01); // Set SBYB bit for Active mode } void MPL3115A2::setOversampleRate(char sampleRate) { if(sampleRate > 7) sampleRate = 7; // OS cannot be larger than 0b.0111 sampleRate <<= 3; // Align it for the CTRL_REG1 register char temp = i2cRead(CTRL_REG1); // Read current settings temp &= 0xC7; // Clear out old OS bits temp |= sampleRate; // Mask in new OS bits i2cWrite(CTRL_REG1, temp); } void MPL3115A2::enableEventFlags() { i2cWrite(PT_DATA_CFG, 0x07); // Enable all three pressure and temp event flags } void MPL3115A2::toggleOneShot(void) { clearRegisterBit(CTRL_REG1, 0x02); // Clear OST bit setRegisterBit(CTRL_REG1, 0x02); // Set the OST bit. } void MPL3115A2::clearRegisterBit(const char regAddr, const char bitMask) { char temp = i2cRead(regAddr); // Read the current register value temp &= ~bitMask; // Clear the bit from the value i2cWrite(regAddr, temp); // Write register value back } void MPL3115A2::setRegisterBit(const char regAddr, const char bitMask) { char temp = i2cRead(regAddr); // Read the current register value temp |= bitMask; // Set the bit in the value i2cWrite(regAddr, temp); // Write register value back } char MPL3115A2::i2cRead(char regAddr) { _i2c->start(); // Start if (_i2c->write(MPL3115A2_ADDRESS)!=1) // A write to device debugOut("MPL3115A2::i2cRead: Sensor failed to respond to write request at address 0x%X\r\n", MPL3115A2_ADDRESS); if (_i2c->write(regAddr)!=1) // Register to read debugOut("MPL3115A2::i2cRead: Sensor at address 0x%X did not acknowledge register 0x%X\r\n", MPL3115A2_ADDRESS, regAddr); _i2c->start(); if (_i2c->write(MPL3115A2_ADDRESS|0x01)!=1) // Read from device debugOut("MPL3115A2::i2cRead: Sensor failed to respond to read request at address 0x%X\r\n", MPL3115A2_ADDRESS); char result = _i2c->read(READ_NAK); // Read the data _i2c->stop(); return result; } void MPL3115A2::i2cWrite(char regAddr, char value) { char cmd[2]; cmd[0] = regAddr; cmd[1] = value; if (_i2c->write(MPL3115A2_ADDRESS, cmd, 2) != 0) debugOut("MPL3115A2::i2cWrite: Failed writing value (%d, 0x%X) to register 0x%X\r\n", value, regAddr); } void MPL3115A2::debugOut(const char * format, ...) { if (_debug == NULL) return; va_list arg; _debug->printf(format, arg); }