.. _fview_ext_trig-overview: ********************************************************** Camera trigger device with precise timing and analog input ********************************************************** .. index:: single: fview_ext_trig single: analog input single: synchronization .. _camtrig: camtrig -- Camera trigger device firmware ========================================= **camtrig** - firmware for precisely timed trigger generation with synchronized analog input Why --- Triggering your camera is useful to synchronize it with other devices. These other devices can be other cameras, so that images are taken simultaneously, or a computer, so that the images can be correlated with other activity. What ---- .. image:: usbkey.jpg :alt: Atmel AT90USBKEY Camtrig is firmware for the $30 AT90USBKEY__ USB development board that: __ http://atmel.com/dyn/products/tools_card.asp?tool_id=3879 1. generates trigger pulses to feed into the external trigger input of digital video cameras. The pulses are generated with a 16-bit hardware timer using an 8 MHz crystal oscillator to produce very regular timing. 2. communicates synchronization information with software running on a PC. By repeatedly querying for timestamps from the USB device, the PC is able to make a model of the gain and offset of the two clocks with computed precision. 3. acquires analog voltage streams. The AT90USBKEY has a multiplexed 10-bit analog-to-digital converter (ADC), which can sample from 0.0 to 3.3 volts and operates up to 9.6 KHz using :mod:`motmot.fview_ext_trig`. 4. produces digital pulses to trigger other hardware. 5. provides a GUI plugin to :mod:`fview` that includes a display like a strip-chart recorder. This plugin is :mod:`motmot.fview_ext_trig`. .. image:: screenshot-small.png How --- The device is accessed using the Python :mod:`motmot.fview_ext_trig` package. Camtrig is built with GCC-AVR using the LUFA_ library for the AT90USBKEY. To load the firmware onto the device, use `dfu-programmer`__ or FLIP__ to transfer the hex file camtrig.hex_ to the device in Device Firmware Upload (DFU) mode. __ http://dfu-programmer.sourceforge.net/ __ http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3886 Where ----- The source code for the camera trigger device is kept in the `fview_ext_trig git repository`_ under the `CamTrigUSB directory`_. Alternatively, download the released Python code at the `PyPI page`_ and the firmware, camtrig.hex_, from github. .. _fview_ext_trig git repository: http://github.com/motmot/fview_ext_trig/tree/master/ .. _CamTrigUSB directory: http://github.com/motmot/fview_ext_trig/tree/master/CamTrigUSB .. _motmot: http://code.astraw.com/projects/motmot .. _LUFA: http://www.fourwalledcubicle.com/LUFA.php .. _PyPI page: http://pypi.python.org/pypi/motmot.fview_ext_trig .. _camtrig.hex: http://github.com/motmot/fview_ext_trig/raw/master/CamTrigUSB/Projects/MotmotCamTrig/camtrig.hex More information ---------------- .. toctree:: :maxdepth: 1 README-firmware.rst wiring.rst