To synchronize data streams from multiple devices (in my case MEG, EMG and trigger/marker signals), one needs a way to know the temporal shift between them. This is the repository for a handy tool that can generates spikes on an analog channel (0-5V range in steps from 0-4095). These can also be used as condition markers (e.g., in mne). It is plugged in via USB and there is a simple python interface to spike synchronization triggers or experiment markers.
We used an Arduino Nano and 2 MCP4725 12-bit DACs
Sources can be found in the corresponding folders. The Arduino C++-Code requires the library MCP4725.
The interface to use triggers is in python and needs only pyserial
To send the information in the most efficient way possible, we only send necessary information to the Arduino. Therefore, we reconstruct the struct Trigger in DAC.h exactly with our TriggerStruct in triggerduino.py, which inherits from ctypes.Structure. We send this as a bytestream on the serial port which the Arduino interprets as a triggers. Potentially, more information can be sent to the Arduino, but then it is important to keep the order and type of values consistent between python and C.