SLAAE27 June 2021 MSP430FR2155 , MSP430FR2155
4.1 Stepper Motor Output
The DRV8428 is used as the stepper motor driver for focus and tilt motor control. MSP430FR2155 controls M0 and M1 pins to configure the step mode for each of the stepper motor as shown in the Table 4-1.
| M0 | M1 | Step Mode |
|---|---|---|
| 0 | 0 | Full step (2-phase excitation) with 100% current |
| 0 | 330kΩ to GND | Full step (2-phase excitation) with 71% current |
| 1 | 0 | Non-circular 1/2 step |
| Hi-Z | 0 | 1/2 step |
| 0 | 1 | 1/4 step |
| 1 | 1 | 1/8 step |
| Hi-Z | 1 | 1/16 step |
| 0 | Hi-Z | 1/32 step |
| Hi-Z | 330kΩ to GND | 1/64 step |
| Hi-Z | Hi-Z | 1/128 step |
| 1 | Hi-Z | 1/256 step |
Decay mode for the stepper motor driver can be chosen for the required operation and noise. For more details, see DRV8428 Stepper Driver With Integrated Current Sense, 1/256 Microstepping, STEP/DIR Interface and smart tune Technology Data Sheet.
MSP430FR2155 sets the direction, speed and pulse-count to control the angle and speed of the rotation. Direction, speed and pulse count are configurable in the software. Figure 4-1 and Figure 4-2 show the step and direction inputs, and voltage outputs for full-step mode at 100 PPS.
Figure 4-1 STEP Input, DIR Input, Voltage Outputs
AOUT1, BOUT1 for Full-Step Mode (M0 = M1 = 0), 100 PPS
Figure 4-2 Voltage Outputs at No-Load AOUT1, AOUT2,
BOUT1, BOUT2 for Full-Step Mode, 100 PPSFigure 4-3, Figure 4-4, and Figure 4-5 show the coils currents (I-AOUT, I-BOUT) for different stepping modes.
Figure 4-3 Coil Current I-AOUT, I-BOUT for 1/2 Step
Mode, 100 PPS
Figure 4-4 Coil Current I-AOUT, I-BOUT for 1/8 Step
Mode, 100 PPS
Figure 4-5 Coil Current I-AOUT, I-BOUT for 1/128
Step Mode, 100 PPS