1. Description

shuttlexpress is a userspace HAL component that interfaces Contour Design’s ShuttleXpress device with LinuxCNC’s HAL. The ShuttleXpress has five momentary buttons, a 10 counts/revolution jog wheel with detents, and a 15-position spring-loaded outer wheel that returns to center when released.

If it is started without command-line arguments, it will probe all /dev/hidraw* device files for ShuttleXpress devices, and use all devices found. If it is started with command-line arguments, only will only probe the devices specified.

The ShuttleXpress device has an internal 8-bit counter for the current jog-wheel position. The shuttlexpress driver can not know this value until the ShuttleXpress device sends its first event. When the first event comes into the driver, the driver uses the device’s reported jog-wheel position to initialize counts to 0.

This means that if the first event is generated by a jog-wheel move, that first move will be lost.

Any user interaction with the ShuttleXpress device will generate an event, informing the driver of the jog-wheel position. So if you (for example) push one of the buttons at startup, the jog-wheel will work fine and notice the first click.

2. Setup

The shuttlexpress module needs read permission on the /dev/hidraw* device files. This can be accomplished by adding a file /etc/udev/rules.d/99-shuttlexpress.rules, with the following contents:

SUBSYSTEM=="hidraw", ATTRS{idVendor}=="0b33", ATTRS{idProduct}=="0020", MODE="0444"

3. Pins

  • shuttlexpress.<DeviceNumber>.button-<ButtonNumber> (bit out) The ShuttleXpress has five buttons around the outside of the device, numbered 0 through 4. 0 is the counter-clockwise-most button, 4 is the clockwise-most button. These pins are True (1) when the button is pressed.

  • shuttlexpress.<DeviceNumber>.button-<ButtonNumber>-not (bit out) These pins have the inverse of the button state, so they’re True (1) when the button is not pressed.

  • shuttlexpress.<DeviceNumber>.counts (s32 out) Accumulated counts from the jog wheel (the inner wheel).

  • shuttlexpress.<DeviceNumber>.spring-wheel-s32 (s32 out) The current deflection of the spring-wheel (the outer wheel). It’s 0 at rest, and ranges from -7 at the counter-clockwise extreme to +7 at the clockwise extreme.

  • shuttlexpress.<DeviceNumber>.spring-wheel-f (float out) The current deflection of the spring-wheel (the outer wheel). It’s 0 at rest, -1 at the counter-clockwise extreme, and +1 at the clockwise extreme. (The ShuttleXpress device reports the spring-wheel position quantized from -7 to +7, so this pin reports only 15 discrete values in it’s range.)