This motion controller can control up to three stepper motor axes for pan, tilt, dolly, etc. motion. The design consists of a motor control and driver board, and a handheld user interface with LCD display.
Motion Controller
The brain of the motion rig controller is an Arduino microcontroller. Arduinos are simple to program, are cheap, and are ubiquitous. Although tiny, even the most basic Arduino has more than enough horsepower to handle this application.
The control software is fairly simple. The default mode is move-shoot-move. This mode is perfect for time-lapse photography, and especially for long exposure time-lapses.
To configure/program the device, the following parameters are set using the handheld interface:
- Number of frames for the sequence
- Exposure time per frame
- Start/End positions for each axis
Once configured, the controller can perform a test run, shooting only first and last frames and moving at faster speed in between. This is useful to review the programmed motion quickly, and fine tune the program.
Of course, since the brain of this device is an Arduino, the codes easily changed to do practically anything else.
Modular Drivers
Each stepper motor is controlled by an Allegro A4988 stepper driver with up to 16x micro-stepping capability. Micro-stepping allows for finer control of the motor steps, which means finer positioning accuracy. The drivers are mounted on modular carrier boards. These boards are dirt cheap, thanks to their popularity with 3D printers. If one of these boards happens to burn out, it is easily replaced .
Handheld Interface
The handheld user interface provides a backlit LCD and a 5 button navigation pad (up/down/left/right/select). The interface allows for controlling and configuring the rig. The interface displays current status during motion sequences.
Integrated Shutter Release
The controller includes a port to act as an external shutter release for dSLR cameras. The port mimics a typical remote shutter release and can command both autofocus and shutter release functions. Because the motion controller controls the shutter release, it allows for perfect synchronization of the shutter and motors.
The integrated camera control has been tested on Canon dSLR cameras. Other brands are likely to work as well, but are untested at this time.
