Sub-nanosecond time interval counter built on a shield for the Arduino Mega 2560. The TICC is available from https://tapr.org/product/tapr-ticc/.

NOTE: Going forward, the "main" brach is the current development branch. Each release is in its own branch named with version number.

The TICC is a circuit board mated to an Arduino Mega 2560 controller that allows very high resolution time interval measurements -- down to less than 60 picoseconds (trillionths of a second).

The software in this repo runs on the Mega 2560 and controls the shield. Measurement data is output in ASCII form on the Arduino's USB port. In the latest version, there is also a high-speed mode that outputs binary data at nearly double the rate of the ASCII output.

Source files are contained in the "TICC" folder which is an Arduino sketch folder.

Binary ".hex" files are in the binaries/ folder. Several upload tools for Windows, Linux, and Mac are in the bin/ folder. Instructions for using one of them, AVRDUDESS, will be in an appendix to the updated User Guide which will be in the docs/ folder as soon as it's ready.

See the CHANGES.md file for more details about versions. This is just a short summary:

October 2025: This is a new release in which much of the code has been rewritten with (hopefully) better performance, more features, and several bug fixes. Highlights:

• New timestamp modes -- strict ascending timestamp order, or paired channel output (e.g., always chA/chB/chA/chB ordering)
• Much greater measurement speed, including binary timestamp mode that can do over 1000 measurements/second on one channel
• Timestamps don't overflow for 68 years
• Fix to bug in printing long timestamps (misplaced "-" sign)
• Fully reworked menu system with submenus and multiple command execution for scripting

12 April 2020: New firmware version that adds:

• Change to 11 decimal place (10 ps) rather than 12 place (1 ps) resolution to better reflect real performance
• Selectable timestamp rollover
• Changes to support multi-TICC
• Other cleanup