[throwanem]

I've seen USB GPIO breakouts, but not very cheaply, and I suspect driver support might be an issue. Certainly controlling GPIOs via /sys is extremely convenient! Between that and the built-in Ethernet interface, I suspect a Raspberry Pi makes a better GPIO interface for a PC than almost anything else on the market.

[candiodari]

Really ? Because this is trivial to make using a microcontroller. Or you can use any FT232 serial interface.

I mean I'd think you'd prefer an arduino for this application over pretty much everything else since you can quickly upload small programs to the arduino that keep the "fast" logic on the arduino.

[throwanem]

Arduinos cost more than a lot of Pis, though. And the network interface of a Pi enables some really interesting capabilities that don't exist, or are harder to obtain, with a device that doesn't have one.

[thearn4]

I think ESP8266 boards (running something NodeMCU) are becoming the more popular replacements for Arduino. They're super cheap, and have integrated Wifi.

Cool thing about them is that you can write in C-like AVR code (like Arduino), or micro versions of Lua, Python, and other choices.

[agumonkey]

It's extremely cheap, packs of lolin nodemcu for 10$, and that's the "noob kit".

btw ESP32 are reaching the 6-7$ range for module + serial board.

[candiodari]

4 dollars, including shipping. At this price, they're pretty much disposable. Pi's seem to have bad shipping costs, so they're 20$/piece for the cheapest:

https://www.banggood.com/ATmega328P-Nano-V3-Controller-Board...

14 GPIO (although with hacks you can do more), including 10 bit DACs on all of them, and 4 with hardware PWM. Most have alternate functions, like I2C, that can be used.