In the past, we’ve discussed driving a linear resonant actuator using a DRV2605 haptic driver chip from Texas Instruments. Though the DRV2605 chip provides plenty of features (audio to haptics, licensed effects from Immersion, and flexible I2C or PWM input), it also requires a more complicated integration with an existing circuit. Though an extra capacitor or two doesn’t introduce too much complexity, the DRV2605 also isn’t suited for circuits attempting to drive multiple motors at the same time. Since the chip uses I2C, its address remains the same in every chip and cannot be modified. As a result, integrating multiple DRV2605 chips on a single I2C bus requires an I2C switch or multiplexor – multiple slaves cannot be controlled by the same master on the same bus.
There must be a simpler way! And Texas Instruments provides the DRV2603 to provide a simpler option. The DRV2603 haptic driver forgoes the licensed effects and audio input for a simple PWM-only input. Each motor driven with a DRV2603 chip only needs a single digital output pin from a signal source that is capable of producing a signal from 10kHz to 250kHz will be capable of driving multiple motors simultaneously.
For haptics projects that rely on multiple actuators to produce feedback, the DRV2603 provides a simpler way to get started using linear resonant actuators.