AV:Testing Controller Latency

Below is the process used by Porkchop Express and Lemonici for measuring controller latency using a MiSTer. This process and their posted results can be found on this site.

Testing Controller Latency (MiSTer)

Required Materials

• An Arduino Uno/Leonardo/Pro Micro (others will probably also work).
• The NES Lag Tester core.
• The Arduino lag test code by @jorge_ and @lemonici].
• PuTTY (or other telnet client).
• A USB 2.0 cable to be cut.
• IO Board OR DE-10 Nano Latency Testing PCB hat

Setup

1. Upload the Arduino lag test code to the Arduino.
2. Enable 1ms polling on MiSTer by running fast_polling_on.sh
3. Configure the controller you wish to test in the NES Lag Tester core, ensuring that the button you will wire up for testing is mapped.
4. Solder a wire from a button on the controller to digital pin 5 of the Arduino, also solder a wire for GND between the controller and Arduino.
5. Connect digital pin 2 of the Arduino to the User IO TX (D+) line on the IO board or PCB hat. You can do this using a USB 2.0 cable that you cut off. The green wire is D+.
6. Connect GND between the Arduino and USER IO (black wire of the USB cable).

Testing Latency

1. Plug the controller into a free USB port on the MiSTer.
2. Power on the MiSTer and start the NES core. Close the OSD. Press a button or an axis on the controller.
3. Plug the Arduino to a USB port on your computer and start Putty. Start a serial connection to the COM port of the Arduino at speed 115200. The COM port of the Arduino can be found in device manager (on Windows).
4. If the connection was successful, you should now see test data in the Putty console.