Overview
There are 2 main types of haptic actuators: eccentric rotating mass (ERM) and linear resonant actuators (LRA)
Both types can be used with SenseShift, though, ERMs are much easier, since LRAs require additional drivers ICs
Difference between ERMs and LRAs
A video from Precision Microdrives showing the two most common types of vibration motors: eccentric rotating mass (ERM) motors and linear resonant actuators (LRA). ERM motors vibrate in two directions due to the centripetal force of the unbalanced mass attached to the DC motor axle. LRAs are similar in design to speakers.
Hardware requirements
Using ERMs does not require additional hardware and relies only on PWM signal, to change it's amplitude
Using LRAs require external haptic motor driver, though you can use it with ERMs for better haptics, since it can detect internal resonance, apply overdrive and braking overvoltage
| ERM | LRA | |
|---|---|---|
| Without haptic driver | ✅ | ❌ |
| With haptic driver | ✅ | ✅ |