DRV8842: Current not able to control(MSP430F5438A) for the DRV8842PWPR motor driver

Ankal Reddy Gajjala

Part Number: DRV8842
Other Parts Discussed in Thread: MSP430F5438A,

MSP430F5438A Controller is unable to control the current of DRV8842PWPR motor driver with I0 to I4 pins.

The below is configuation from MSP controller side side. Current control is responding only for the PINs I0 and I4. Could you suggest where could be wrong?

P1DIR |= (1 << 2);

P1SEL |= (1 << 2);

P1DIR |= (1 << 3);
P1SEL |= (1 << 3);

TA0CCTL0 |= CCIE;
TA0CCR0 = 0x60; //50Khz frequency
TA0CCTL1 = OUTMOD_4;
TA0CCR1 = 0;

TA0CCTL2 = OUTMOD_4;
TA0CCR2 = 0;
TA0CTL = TASSEL_2 + ID_0 + MC__UPDOWN;

over 5 years ago

0 Wang5577 over 5 years ago

TI__Guru 56650 points

Ankal,

I just can open this post now. Let me check it.

0 Rick Duncan over 5 years ago

TI__Guru** 114905 points

Hi Ankal,

Would you please provide some additional information?

Can you provide a schematic snippet showing the DRV8842 and connections?

Can you provide scope captures of IN1/IN2 and OUT1/OUT2?

What is the VREF voltage?

What current do you see at the outputs?

Please provide current scope captures if possible with I4, I3, I2, I1, and I0 at:
00000
00001
00010
00100
01000
10000

0 Ankal Reddy Gajjala over 5 years ago in reply to Rick Duncan

Prodigy 20 points

I4	I3	I2	I1	I0	Motor Current	Voltage at OUT1
0	0	0	0	1	0.036	4.5v
0	0	0	1	1	0.036	4.5v
0	0	1	1	1	0.036	4.9v
0	1	1	1	1	0.1	13.7v
1	1	1	1	1	0.1	13.7v

To control the Motor speed, should I vary PWM of IN1/IN2?

These I0 to I4 are the only Current limits?

0 Wang5577 over 5 years ago in reply to Ankal Reddy Gajjala

TI__Guru 56650 points

Ankal,

Most Rick's questions have not been answered. It is hard to go next debugging steps.

Motor drivers

Motor drivers forum

DRV8842: Current not able to control(MSP430F5438A) for the DRV8842PWPR motor driver