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- #include "MMA7660.h"
-
- MMA7660::MMA7660(PinName sda, PinName scl, bool active) : _i2c(sda, scl)
- {
- setActive(active);
- samplerate = 64;
-
- }
-
- //Since the MMA lacks a WHO_AM_I register, we can only check if there is a device that answers to the I2C address
- bool MMA7660::testConnection( void )
- {
- if (_i2c.write(MMA7660_ADDRESS, NULL, 0) == 0 )
- return true;
- else
- return false;
- }
-
- void MMA7660::setActive(bool state)
- {
- char modereg = read(MMA7660_MODE_R);
- modereg &= ~(1<<0);
-
- //If it somehow was in testmode, disable that
- if (modereg && (1<<2)) {
- modereg &= ~(1<<2);
- write(MMA7660_MODE_R, modereg);
- }
-
- modereg += state;
- write(MMA7660_MODE_R, modereg);
- }
-
- void MMA7660::readData(int *data)
- {
- if (!active) {
- setActive(true);
- active = true;
- wait(0.012 + 1/samplerate); //Wait until new sample is ready, my experience is that 1/samplerate isnt needed, but datasheet says so
- }
-
- char temp[3];
- bool alert;
-
- do {
- alert = false;
- read(MMA7660_XOUT_R, temp, 3);
- for (int i = 0; i<3; i++) {
- if (temp[i] > 63)
- alert = true;
- if (temp[i] > 31)
- temp[i] += 128+64;
- data[i] = (signed char)temp[i];
- }
- } while (alert);
-
- if (!active)
- setActive(false);
- }
-
-
- void MMA7660::readData(float *data)
- {
- int intdata[3];
- readData(intdata);
- for (int i = 0; i<3; i++)
- data[i] = intdata[i]/MMA7660_SENSITIVITY;
- }
-
- float MMA7660::x( void )
- {
- return getSingle(0);
- }
-
- float MMA7660::y( void )
- {
- return getSingle(1);
- }
-
- float MMA7660::z( void )
- {
- return getSingle(2);
- }
-
-
- void MMA7660::setSampleRate(int samplerate)
- {
- setActive(false); //Not allowed to be active to change anything
- int rates[] = {120, 64, 32, 16, 8, 4, 2, 1}; //Alowed samplerates (and their number in array is also number required for MMA)
- int sampleLoc = 0, sampleError = 10000, temp;
- for (int i = 0; i<8; i++) {
- temp = abs( rates[i] - samplerate );
- if (temp<sampleError) {
- sampleLoc = i;
- sampleError=temp;
- }
- }
-
- //Update the samplerate reg
- temp = read(MMA7660_SR_R);
- temp &= ~0x07; //Awake sample rate are lowest 3 bit
- temp |= sampleLoc;
- write(MMA7660_SR_R, temp);
- this->samplerate = rates[sampleLoc];
- setActive(active); //Restore previous active state
- }
-
-
- MMA7660::Orientation MMA7660::getSide( void )
- {
- char tiltreg = read(MMA7660_TILT_R);
-
- //We care about 2 LSBs
- tiltreg &= 0x03;
- if (tiltreg == 0x01)
- return MMA7660::Front;
- if (tiltreg == 0x02)
- return MMA7660::Back;
- return MMA7660::Unknown;
- }
-
- MMA7660::Orientation MMA7660::getOrientation( void )
- {
- char tiltreg = read(MMA7660_TILT_R);
-
- //We care about bit 2, 3 and 4 (counting from zero)
- tiltreg &= 0x07<<2;
- tiltreg >>= 2;
- if (tiltreg == 0x01)
- return MMA7660::Left;
- if (tiltreg == 0x02)
- return MMA7660::Right;
- if (tiltreg == 0x05)
- return MMA7660::Down;
- if (tiltreg == 0x06)
- return MMA7660::Up;
- return MMA7660::Unknown;
- }
-
-
-
- //////////////////////////////////////////////
- ///////////////PRIVATE////////////////////////
- //////////////////////////////////////////////
-
-
- void MMA7660::write(char address, char data)
- {
- char temp[2];
- temp[0]=address;
- temp[1]=data;
-
- _i2c.write(MMA7660_ADDRESS, temp, 2);
- }
-
- char MMA7660::read(char address)
- {
- char retval;
- _i2c.write(MMA7660_ADDRESS, &address, 1, true);
- _i2c.read(MMA7660_ADDRESS, &retval, 1);
- return retval;
- }
-
- void MMA7660::read(char address, char *data, int length)
- {
- _i2c.write(MMA7660_ADDRESS, &address, 1, true);
- _i2c.read(MMA7660_ADDRESS, data, length);
- }
-
- float MMA7660::getSingle( int number )
- {
- if (!active) {
- setActive(true);
- wait(0.012 + 1/samplerate); //Wait until new sample is ready
- }
-
- signed char temp;
- bool alert;
-
- do {
- alert = false;
- temp = read(MMA7660_XOUT_R + number);
- if (temp > 63)
- alert = true;
- if (temp > 31)
- temp += 128+64;
- } while (alert);
-
- if (!active)
- setActive(false);
-
- return temp / MMA7660_SENSITIVITY;
- }
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