Modes#

The motor runs one control loop at a time, and the active mode decides how it reads the 16-bit value in a drive frame. Switch with set_mode, then drive:

use m0601::Mode;

motor.set_mode(Mode::Current)?;      // sends the 0xA0 switch frame 5×, ~100 ms
motor.drive_current(4096)?;          // ≈ 1 A of torque; resend at 50 Hz to hold

motor.set_mode(Mode::Position)?;     // only legal below 10 RPM
motor.drive_position(16384)?;        // ≈ 180°; resend at 50 Hz to hold

A few things the table doesn’t tell you:

Out-of-range setpoints clamp, they don’t wrap. Ask for more than ±330 RPM and you get ±330, not an integer that rolled over into a reverse command. The clamp is symmetric on purpose — even the current range is ±32767, not i16::MIN, so nothing you pass can wrap to the wrong sign.

The motor never acknowledges a mode switch. set_mode sends the switch frame five times (it’s idempotent, so repeating it just makes it stick) and returns, but the motor sends nothing back to confirm. To know the switch took, read Feedback::mode from the next reply. This is why the CLI’s control dashboard shows the reported mode and flags a mismatch in red — the requested mode is a hope until telemetry confirms it.

Position mode has an entry condition. You can only switch into it while the wheel is turning slower than 10 RPM. Above that the switch is refused by the motor. In your own code, gate it on a telemetry reading first, and fail closed if you don’t have one — an unknown speed is not a slow speed.

Zero means three different things. In velocity mode a zero setpoint stops the wheel; in position mode it commands a move to 0°; in current mode it commands zero torque, which is a coast. This is the single most important fact about the mode system, and it’s why safe_stop forces velocity mode before sending zero.