GOPA KUMAR K C
Gyro_MPU3300
Revision 1:fe48240c4b08, committed 2015-02-13
- Comitter:
- gkumar
- Date:
- Fri Feb 13 17:19:26 2015 +0000
- Parent:
- 0:7e0ed4a0d584
- Commit message:
- Gyro_MPU3300
Changed in this revision
| main.cpp | Show diff for this revision Revisions of this file |
--- a/main.cpp Fri Feb 13 17:17:15 2015 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,175 +0,0 @@
-#include<mbed.h>
-#include "MPU3300.h" //header file which includes all the register addresses and
- //Bit configuration of those registers
-SPI spi (PTD6,PTD7,PTD5) ; // MOSI,MISO, CLOCK pins being used on //microcontroller(in order)
-DigitalOut ssn (PTA13); //Slave Select pin
-Serial pc(USBTX,USBRX);
-InterruptIn dr(PTD2); //Interrupt pin
-Ticker tr; //Ticker function to give values for limited amount of time
-uint8_t trFlag; //ticker Flag
-uint8_t drFlag; //data-ready interrupt flag
-void trSub();
-void drSub();
-void init_gyro();
-void execute_gyro();
-int main(void)
-{
- init_gyro(); //Initializing Gyroscope registers and setting them to our required configuration
- execute_gyro(); //Executing gyroscope for measuring angular rates
- return 0;
-}
-void drSub() //In this function we setting data-ready flag to 1
-{
- drFlag=1;
-}
-void trSub() //In this function we are setting ticker flag to 0
-{
- trFlag=0;
-}
-void init_gyro()
-{
- uint8_t response;
- ssn=1; //Deselecting the chip
- spi.format(8,3); // Spi format is 8 bits, and clock mode 3
- spi.frequency(1000000); //frequency to be set as 1MHz
- drFlag=0; //Intially defining data-ready flag to be 0
- dr.mode(PullDown);
- dr.rise(&drSub);
- __disable_irq();
-
-/*Following the above mentioned algorithm for initializing the register and changing its configuration*/
- ssn=0; //Selecting chip(Mpu-3300)
- spi.write(USER_CTRL|READFLAG); //sending USER_CTRL address with read bit
- response=spi.write(DUMMYBIT); //sending dummy bit to get default values of the register
-
- ssn=1; //Deselecting the chip
- wait(0.1); //waiting according the product specifications
-
- ssn=0; //again selecting the chip
- spi.write(USER_CTRL); //sending USER_CTRL address without read bit
- spi.write(response|BIT_I2C_IF_DIS); //disabling the I2C mode in the register
- ssn=1; //deselecting the chip
- wait(0.1); // waiting for 100ms before going for another register
-
- ssn=0;
- spi.write(PWR_MGMT_1|READFLAG); //Power Management register-1
- response=spi.write(DUMMYBIT);
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(PWR_MGMT_1);
- response=spi.write(response|BIT_CLKSEL_X); //Selecting the X axis gyroscope as clock as mentioned above
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(GYRO_CONFIG|READFLAG); //sending GYRO_CONFIG address with read bit
- response=spi.write(DUMMYBIT);
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(GYRO_CONFIG); //sending GYRO_CONFIG address to write to register
- spi.write(response&(~(BITS_FS_SEL_3|BITS_FS_SEL_4))); //selecting a full scale mode of +/=225 deg/sec
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(CONFIG|READFLAG); //sending CONFIG address with read bit
- response=spi.write(DUMMYBIT);
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(CONFIG); //sending CONFIG address to write to register
- spi.write(response|BITS_DLPF_CFG); //selecting a bandwidth of 42 hz and delay of 4.8ms
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(SMPLRT_DIV|READFLAG); //sending SMPLRT_DIV address with read bit
- response=spi.write(DUMMYBIT);
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(SMPLRT_DIV); //sending SMPLRT_DIV address to write to register
- spi.write(response&BITS_SMPLRT_DIV); //setting the sampling rate division to be 0 to make sample rate = gyroscopic output rate
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(INT_ENABLE|READFLAG); //sending address of INT_ENABLE with readflag
- response=spi.write(DUMMYBIT); //sending dummy byte to get the default values of the
- // regiser
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(INT_ENABLE); //sending INT_ENABLE address to write to register
- spi.write(response|BIT_DATA_RDY_ENABLE); //Enbling data ready interrupt
- ssn=1;
- wait(0.1);
-
- __enable_irq();
-}
-
-void execute_gyro()
-{
- uint8_t response;
- uint8_t MSB,LSB;
- int16_t bit_data;
- float data[3],error[3]={0,0,0}; //declaring error array to add to the values when required
- float senstivity = 145.6; //senstivity is 145.6 for full scale mode of +/-225 deg/sec
- ssn=0;
- spi.write(PWR_MGMT_1|READFLAG); //sending address of INT_ENABLE with readflag
- response=spi.write(DUMMYBIT); //
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(PWR_MGMT_1); //sending PWR_MGMT_1 address to write to register
- response=spi.write(response&(~(BIT_SLEEP))); //waking up the gyroscope from sleep
- ssn=1;
- wait(0.1);
-
- trFlag=1;
- tr.attach(&trSub,1); //executes the function trSub afer 1sec
- while(trFlag)
- {
- if(drFlag==1)
- {
- ssn=0;
- spi.write(GYRO_XOUT_H|READFLAG); //sending address of PWR_MGMT_1 with readflag
- for(int i=0;i<3;i++)
- {
- MSB = spi.write(DUMMYBIT); //reading the MSB values of x,y and z respectively
- LSB = spi.write(DUMMYBIT); //reading the LSB values of x,y and z respectively
- bit_data= ((int16_t)MSB<<8)|LSB; //concatenating to get 16 bit 2's complement of the required gyroscope values
- data[i]=(float)bit_data;
- data[i]=data[i]/senstivity; //dividing with senstivity to get the readings in deg/sec
- data[i]+=error[i]; //adding with error to remove offset errors
- }
- ssn=1;
- for (int i=0;i<3;i++)
- {
- printf("%f\t",data[i]); //printing the angular velocity values
- }
- printf("\n");
- break;
- }
- drFlag=0;
- }
- ssn=0;
- spi.write(PWR_MGMT_1|READFLAG); //sending address of PWR_MGMT_1 with readflag
- response=spi.write(DUMMYBIT);
- ssn=1;
- wait(0.1);
-
- ssn=0;
- spi.write(PWR_MGMT_1); //sending PWR_MGMT_1 address to write to register
- response=spi.write(response|BIT_SLEEP); //setting the gyroscope in sleep mode
- ssn=1;
- wait(0.1);
-}