[korethr]

In the end of the video he lists off the number of things he did that were fancier than necessary. One of them was the use of an Arduino for the pulse duration and switching. I found myself reflexively commenting, "It's called a 555 timer." I'm confident that the same function could be more minimally implemented with a 555 timer and maybe a couple other supporting chips. But he's probably getting more consistent control of pulse duration and it was probably easier for him to implement as well.

[kragen]

He's probably getting a lot more error from using an AC solid-state relay (which probably uses a triac and so probably stays on until the next zero-crossing, thus a 10-millisecond error) than he'd get from using some metal-film resistors, a film capacitor, and a 555. But the Arduino has a much easier time displaying the pulse duration on the LEDs.

[geon]

Having digital timer settings would be tricky without a processor, I imagine.

[sokoloff]

It’s also likely faster to implement as a one-off for a hobbyist and, using a low-cost MCU, cheaper than building it around a $0.10 555 if you want to make a product.

https://cpldcpu.wordpress.com/2019/08/12/the-terrible-3-cent...