MMA8451Q ACC support

[ronco]

Hi,

i did some tests with the MMA8451Q (http://cache.freescale.com/files/sensor ... A8451Q.pdf) it seems to be a good one

i did a I2C support code that works .. i dont know if its good .. it may be improved with LPF settings and such stuff..

Code: Select all

// ************************************************************************************************************
// I2C Accelerometer MMA8451Q 
// ************************************************************************************************************
#if defined(MMA8451Q)

#define MMA8451Q_ADDRESS 0x1C (standard)
//#define MMA8451Q_ADDRESS 0x1D

void ACC_init () {
  delay(10);
  i2c_writeReg(MMA8451Q_ADDRESS,0x2A,0x05); // wake up & low nois
  delay(10);
  i2c_writeReg(MMA8451Q_ADDRESS,0x0E,0x02); // full scale range
  acc_1G = 512; // should be 1023 but 512 is knowen in MWC
}

void ACC_getADC () {
  TWBR = ((F_CPU / 400000L) - 16) / 2;
  i2c_getSixRawADC(MMA8451Q_ADDRESS,0x00);

  ACC_ORIENTATION( ((rawADC[1]<<8) | rawADC[0])/32 ,
                   ((rawADC[3]<<8) | rawADC[2])/32 ,
                   ((rawADC[5]<<8) | rawADC[4])/32);
  ACC_Common();
}
#endif

//as im on a new PC with win 8 .. i still dont get My SVN clinet to work
//so would someone here be so kind to add this support ?

Edit:
it workes now .. and i added the support

Thanks

regards

Felix

[timecop]

wow, that's pretty awesome! Where'd you find such amazing accel?

[ronco]

hi,

from freecale .. it will be on a new flyduino FC.. we testing the prototypes ATM

regrads Felix

[timecop]

Nice to see Flyduino doing all this innovation!

[ronco]

.. somehow i cant belive that you mean what you say
but if so .. thanks .. ill try to do my best.

i added the MMA8451Q support now .. and also the defines for the new Flydu Ultra FC

regards

Felix

[jy0933]

if you guys dont mind me ask

what is the advantage of this over adxl345 or mpu60xx?

[timecop]

The advantage is flyduino has a lot of these in stock, so they gotta use them for something, hahaha.

[ronco]

if you guys dont mind me ask

what is the advantage of this over adxl345 or mpu60xx?

hi,

basicly it is just like many other ACC's with a high resolution but it has some extra features that may be helpful .. the problem with MPU6050 only setups is that you can just setup one LPF fore both gyro and ACC ..
so a seperate acc inst that bad if you have space for it

regards

felix

[jy0933]

i think current mwc code only has gyro_lpf for setup for now.... the acc still under the LPF_factor thing..not a stand alone(user adjustable ) lpf

but yeah.. will be pretty interesting to see how a separate lpf works out.... (personally i think the separate acc lpf might help with alt maintain on Z axis readings)