CCS/MSP430G2553: How the timer initialization done in “DRV8313EVM_RevB”.

Hello,

I'm not familiar to DRV8313 2-Quardent Uni-Polar drive mode. But according to the timer initialization code, the Timer A0 Compare channel 2 and Timer A1 Compare channel 2 to generate PWM at pin TA0.2 and TA1.2. Please see the MSP430G2x53, MSP430G2x13 Mixed Signal Microcontroller datasheet (Rev. J) and MSP430x2xx Family User's Guide (Rev. J) Timer A module for more information. 

Dear Sir,

Thanks, this is the MSP430G2553 code issue, 

Using timer TA1.2, 3-PWM signal generated by the ports P2.4, P2.5, P3.3, it's fine and TA0.2 is used for P3.0

But how P3.1, P3.2 generates the active signals pulse? Not able to understand with the above timer initialization code.

Regards

Ajeet

Hello,

I checked the DRV8313 datasheet and the schematic of DRV8313EVM.

It seems that the DRV8313 doesn't support separated control for high side and low side switch. The states of each leg are high, low and Hi-Z which are controlled by the INx and ENx signal.

So I think the active signal on bottom side doesn't mean PWM pulse. It means a ON state. The 2-Quardent Uni-Polar drive mode is implemented by the PWM on INx lines and signal on ENx lines. Just like the trapezoidal commutation described in DRV8313 datasheet. 

Thanks for detail of DRV8313, 

But my question is how to generate the signal on ENx lines ? and how the MSP430G2553 Pin 3.0, 3.1, 3.2 generates the signal for ENx lines. Which timer is used

Regards

Ajeet

Hello,

To generate high/low signal, you can use the pin as GPIO output function. Take P3.0 as example,

P3DIR |= BIT0;   // Set as output

P3OUT |= BIT0; // Output high

P3OUT &= ~BIT0; // Output low

To generate PWM signal, the pin need a Timer PWM out function, such as TAx.y. x and y represents x Timer A module and y channel.

       TAxCCR0 = period;             // Set PWM period

       TAxCCTLy = OUTMOD_6; // Set PWM output mode

       TAxCCRy = duty;               // Set PWM dutycycle

       TAxCTL =TASSEL_2 + MC_3 + TACLR ; // Up-Down Mode, SMCLK, Timer Clear

Thanks sir

Also, I am not able to understand, in DRV8313 EVM given program,

In EVM Back emf sensed but in the code only VDC bus sense, so how the Insta_Spin.h is working without back emf voltage.

void Init_ADC ()
{
ADC10CTL0 |= SREF_1 + ADC10SHT_2 + ADC10ON + ADC10IE + REFON + REF2_5V;
ADC10CTL1 = INCH_6 + CONSEQ_0 + ADC10SSEL_2 ; // Sequence of channels upto A6
ADC10AE0 |= 0x40;
}

Regards

Ajeet

Great Improvement in BLDC motor running performance with this change (CONSEQ_0 => CONSEQ_1 ), please correct in the main program in DRV8313EVM software.

Please also clarify, how the sensed 3-phase  back emf linked to the Insta_spin.h file, for implement the instaspin algorithm? while no adc variable defined in main.c code.

Regards

 Ajeet