External FFB mode
The external FFB mainclass (id 3, sys.main=3 to enable) is a normal HID gamepad without PID effects. Instead the effects can be managed using serial or HID commands with the usual command system. Check out FFB manager commands for a list of commands.
Effects can be conditional or non conditional or periodic and have a type id.
- Constant force = 1
A constant force effect has only a magnitude value (and scaler per axis) and applies this magnitude directly as a constant output torque.
- Ramp = 2
- Square = 3
- Sine = 4
- Triangle = 5
- Sawtooth up/down = 6/7
Periodic effects have a magnitude and period and can also have an envelope and phase which is not currently accessible in this mode.
- Spring = 8
- Damper = 9
- Inertia = 10
- Friction = 11
Conditional effects have condition blocks per axis with a saturation and coefficient value. The coefficient is different from the maginitude because there can be a different one for each axis.
A high coefficient makes a strong spring or damper for example.
Each effect has to be created first and enabled. The FFB state also must be enabled to change from idle mode to FFB effect mode.
Check out the python examples on how to control effects via the HID protocol.
OpenFFBoard project