We can now detect light with a analogRead(A0) command. It’s so simple you don’t even need a breadboard!įirst I wired up an LDR (Light Dependent Resistor) to the board’s analog in pin A0, and connected the other end to the ground. I used a cheap Arduino Uno with an LCD/button shield (they call things you stick on them shields, ok?) to do it. For my purposes, I wanted to measure the exact latency between a button press on an Atari 2600 console and the display pixels changing. Instead of getting lost in subjective testing by “feel”, let’s get scientific about it. (Note: I was going to say “twitch gaming” instead of “fast response controls” but I’m guessing that term is too ambiguous these days) Measuring input lag accurately I’m sure things will continue to improve given the recent focus on reducing input lag on both displays and controllers.

Additionally, there are sometimes trade-offs like screen tearing and visual artifacts when you’re aiming at ultra-low latency. That said, I have not been able to do it yet with my setups. Woah, settle down, I didn’t say that! Retro emulation is astonishing and with the right gear and settings it should be possible to match or even beat old-school latency in specific cases such as with Run Ahead on the NES. So real hardware and CRTs are the only way to go for fast response controls? This goes for much of the 8 and 16 bit action content from consoles and computers of yesteryear. (for example, the Atari 2600 polls 30 times a second, during the vertical blank interrupt but ) A lot depends on the number of frames missed as well as when the console polls. We can all automatically do it, sure, but it’s… different. It’s not just about reaction times – there is this thing your brain does where it’s forced to jump and move slightly earlier than the onscreen action. The game is more difficult and less comfortable with the extra lag. Play the murderous Super Mario Brothers 2 (Japan) directly from a Famicom on an old school CRT and then try the same thing on your Raspberry Pi, PC, or even the same NES console through an upscaler/LCD tv.Īs you switch back and forth you’ll probably feel the difference.

Controller input delay test