I haven't touch anything like this in a good while, how cheap could I get a simple Arduino style chip with a few gpio to drive a yellow LED in 2025?

▲

bluescrn 4 days ago | parent | next [-]

Search YouTube for '10 cent microcontroller' to learn about the absolute cheapest chips.

For £3.50 you can get an ESP32 module with WiFi and Bluetooth (e.g. https://thepihut.com/products/esp32-c3-mini-development-boar...)

(A regular Arduino board might still be the best choice if you're just learning/tinkering though)

▲

alnwlsn 4 days ago | parent | prev | next [-]

For an "official" answer (programmable from Arduino IDE, genuine new chips) you can get an ATTINY202 from DigiKey or Mouser for $0.50 in qty. 1.

▲

bombela 4 days ago | parent | prev | next [-]

I have a bag of attiny13a that cost me $0.20 per chip. It is fully self contained. Just add a very small capacitor, give it from 2.8V to 5V. And then you program it the way you want. You can even program and debug it via a single pin if you wish.

At this cost for a hobbyist it's just hard to beat. It can be anything you want it to be in a few lines of code.

I personally write Rust for it, not Arduino C++, but it would work just the same.

▲

Liftyee 4 days ago | parent [-]

What toolchain do you use to compile Rust for it? I have about had enough of undebuggable random Arduino segfaults.

▲

bombela 4 days ago | parent [-]

The main Rust compiler. https://doc.rust-lang.org/nightly/rustc/platform-support/avr...

▲

stavros a day ago | parent [-]

Do you know of any sort of tutorial for this? I'd love to have a play.

▲

bombela 5 hours ago | parent [-]

I do not, sorry. You can read the datasheet of the chip learn everything about it. You can then search online for some implementation of firmware uploader/programmer like "avrdude". Those chips are very simple, all controlled by toggling bits and values in registers.

	▲	stavros 5 hours ago \| parent [-]
		I'll try that, thanks.

▲

alias_neo 4 days ago | parent | prev | next [-]

You could grab any Atmega328p or similar DIL on eBay for a couple of quid, maybe less in batches.

I've got dozens of them in my electronics drawers I don't really use anymore since ESP32 dev boards are so cheap and capable for home projects.

▲

andoando 4 days ago | parent | prev | next [-]

You can get a bluetooth/wifi enabled microcontroller like a Pi Pico 2 for $5 or a full on computer running linux for $15 (Pi zero 2)

▲

the__alchemist 3 days ago | parent | prev | next [-]

Buy any dev board that includes an LED. Nordic, ST, Espressif... doesn't matter for something like this.

▲

cluckindan 4 days ago | parent | prev | next [-]

If you just need it to blink at some interval, get a NE555 for a dime.

Granted, you can almost get a microcontroller for that price…

▲

dgacmu 4 days ago | parent [-]

You actually can: The Puya PY32 ranges from about $0.08 on up (well, $0.15 if you only want to buy 5, but the cheapest one is $0.0959 in qty 200 and $0.0676 in qty 5000+). ARM Cortex m0 in a 10-pin ESSOP-10 surface mount package: https://lcsc.com/product-detail/Microcontrollers-MCU-MPU-SOC...

Kind of mind-blowing. 24mhz 32-bit computer for under a dime.

But you'll learn more about the analog-ish world and not need to deal with SMD if you go the 555 route. And it'll save you power vs the astable monovibrator with NPN transistors.

	▲	dccoolgai 3 days ago \| parent [-]
		555s are so much fun. It's bananas how much you can do with that chip and a few dirt-cheap resistors and capacitors. Make has a really nice little book where they walk you through some simple projects on a breadboard with 555s, transistors, etc. https://www.amazon.com/How-Use-Breadboard-Make-Handbook/dp/1...

▲

roboror 4 days ago | parent | prev [-]

Like $2 if you're patient