My 200mW red laser arrived today, and I wanted to try it out. At this power the laser qualifies as a Class 3B device and hazardous if the eye is exposed directly. Because of this I ordered some laser eye protection. However the eye protection has not yet arrived. Class 3B diffuse reflected light isn't hazardous, so it will be safe to shoot the laser at a wall and observe the spot. My wall are black fabric so that should be safe. So I plugged the setup in and had a bright red spot on the wall.
The reason I wanted this laser was because it has a TTL input that can be switched up to 20 kHz. That means I can control it with an external source such as an Arduino. I wanted to test this, so I started with the program I wrote for my bicycle generator. It makes a PWM signal from a potentiometer input. It didn't take long before I had the laser dimming with the PWM input.
While I have parts that would make it so I could play more, I need to wait until my eye protection arrives before doing anything else. But so far, so good.