I am using MMA955l pedometer sensor in STM32l4RTC MCU, which is connected to i2c and I need to read accelerometer data from chip. I did not find any sample source and going through datasheet and looking at examples I am following command sequence as :
aTxBuffer[0] = 0x00;
aTxBuffer[1] = 0x00;
aTxBuffer[2] = 0x00;
aTxBuffer[3] = 0x0C;
MMA955L_AcclDataTx(aTxBuffer, 4); //Read ID command
//Read Pedometer ID
MMA955L_AcclDataRx(aRxBuffer, 16);
Note: I get response as :
0x00 0x80 0x0c 0x0c 0x7a 0xed 0x25 0x5d 0x01 0x01 0x02 0x02 0x01 0x06 0x03 0x41 when I read 16 bytes of data.
//command to request_to_start register configuration
aTxBuffer[0] = 0x01;
aTxBuffer[1] = 0x10;
aTxBuffer[2] = 0x00;
aTxBuffer[3] = 0x04;
MMA955L_AcclDataTx(aTxBuffer, 4);
aTxBuffer[0] = 0x01;
aTxBuffer[1] = 0x20;
aTxBuffer[2] = 0x00;
aTxBuffer[3] = 0x04;
aTxBuffer[4] = 0xAA;
aTxBuffer[5] = 0xBB;
aTxBuffer[6] = 0xCC;
aTxBuffer[7] = 0xDD;
HAL_Delay(100);
MMA955L_AcclDataTx(aTxBuffer, 8);
//Interrupt_App_IDs register configuration
aTxBuffer[0] = 0x01;
aTxBuffer[1] = 0x20;
aTxBuffer[2] = 0x0C ;
aTxBuffer[3] = 0x04;
aTxBuffer[4] = 0x06;
aTxBuffer[5] = 0x00;
aTxBuffer[6] = 0x00;
aTxBuffer[7] = 0x00;
MMA955L_AcclDataTx(aTxBuffer, 8);
//Awake accelerometer
aTxBuffer[0] = 0x12;
aTxBuffer[1] = 0x20;
aTxBuffer[2] = 0x06;
aTxBuffer[3] = 0x01;
aTxBuffer[4] = 0x00;
MMA955L_AcclDataTx(aTxBuffer, 5);
//Put accel in legacy mode
aTxBuffer[0] = 0x18;
aTxBuffer[1] = 0x20;
aTxBuffer[2] = 0x00;
aTxBuffer[3] = 0x01;
aTxBuffer[4] = 0x10;
MMA955L_AcclDataTx(aTxBuffer, 5);
//Configure accelerometer xyz data
aTxBuffer[0] = 0x4;
aTxBuffer[1] = 0x20;
aTxBuffer[2] = 0x00;
aTxBuffer[3] = 0xC;
aTxBuffer[4] = 0x06;
aTxBuffer[5] = 0x00;
aTxBuffer[6] = 0x06;
aTxBuffer[7] = 0x01;
aTxBuffer[8] = 0x06;
aTxBuffer[9] = 0x02;
aTxBuffer[10] = 0x06;
aTxBuffer[11] = 0x03;
aTxBuffer[12] = 0x06;
aTxBuffer[13] = 0x04;
aTxBuffer[14] = 0x06;
aTxBuffer[15] = 0x05;
MMA955L_AcclDataTx(aTxBuffer, 16);
//Reading aggregated data
aTxBuffer[0] = 0x12;
aTxBuffer[1] = 0x20;
aTxBuffer[2] = 0x06;
aTxBuffer[3] = 0x01;
aTxBuffer[4] = 0x00;
MMA955L_AcclDataTx(aTxBuffer, 5);
//POst this read 6 bytes data
