Other Parts Discussed in Thread: DRV2604, , USB2ANY
Currently using the DRV2604EVM-CT kit to test several different haptic actuators and evaluate the DRV2604 for ease if implementation into a design. I ran into a couple issues when using the driver in the LRA mode -
- In Demo Mode 1, you can use the cap sense buttons to output a generic alert buzz, using both auto-resonance on and off. I scoped the output of the driver, using the dedicated filtered out+/- and ground clips with two scope inputs (suggested by this app note), to try to measure the drive frequency being used. With auto-resonance off, Channel 1 - Channel 2 showed a clean sine-like wave at about 180 Hz. However, with auto-resonance enabled, the output drive had a significant high-frequency component, looked choppier and of smaller amplitude, and the LRA was noticeably weaker. What might cause the closed-loop output to not work as well? LRA option 1, LRA option 2 are the haptics being used.
- In Binary mode 5, I attempted to change the output frequency of the driver manually. However, when pressing B1 and B2, no output was sent to the LRA, and the colored button above the button lit up. I expected the output to be driven, like Demo mode 1. I also selected "set LRA output" in binary Mode 0. The ultimate goal would be to do an infinite buzz test, similar to that offered by Binary mode 7, but with a set LRA frequency.
- When driving the LRA in auto-resonance mode, we noticed a significant drop in supply current and a drop in output frequency when a mechanical force was applied to the LRA externally. In general, is this something you would expect to affect the closed-loop drive of the DRV2604?
