This $200 device will Rickroll anyone who comes within six feet of it | Hacker News Reader

This $200 device will Rickroll anyone who comes within six feet of it

thenextweb.com

18 pointsiProject11 comments

I like that the song doesn't restart at the beginning but resumes! What a nice project.

While a funny joke to play on people, I don't think this is what a "Rickroll" is. https://en.wikipedia.org/wiki/Rickrolling

All you are doing is playing this Rick Astley song when someone comes near. Which is not the "bait & switch" aspect of a true Rickroll.

Anyone else click on the second link and take a few seconds to realize what just happened?

costs about $150 more than it needs to, that is inevitable when you "Componentize" small electronics. Learn about the stuff you're using, or get another hobby.

It's expected to cost more than what you'd think it's worth if you're just making one. A significant chunk of the cost is on general stuff: wire, glue, solder, etc.

Possible cost cutting options I thought of:

Since it's only playing one song, you actually wouldn't need the MP3 shield. There are many tutorials online for wav playback on Arduino without a shield and the Arduino can easily read a SD card using a logic level converter ($1, max). The sound quality will be low but it's cheap! Ultrasonic sensors are cheap on eBay, you could also go with a passive IR sensor.

Of course you could build your own Arduino compatible board for about $10 but you'd need a way to program it (ICSP isn't exactly cheap either).

why isn't icsp cheap? can't you just make a usbtiny with $10 in parts? my icsp consists of 1 tiny85 chip, 3 resistors, 2 diodes, and 1 usb cable.

Your reply to mine is dead. I've read that book. Why does it remind you of it?

Will you elaborate?

He's mad that an Arduino + Motion sensor + MP3 player costs $100 when the parts used to make those three things cost significantly less, and the expensive parts are unnecessary to solve the same problem. (The microcontroller on an Arduino is like $1 in quantity. The special terminals, though, are about $5. This is, incidentally, why cheap dev boards like the STM32F4DISCOVERY have more features and are half the cost of an Arduino: they cut out the expensive parts.)

What he doesn't understand is that the economics are different when you are making one unit versus 100,000 units. (But if you are thinking 5 or 10 units, then it starts to become financially advantageous to start avoiding the hobbyist stuff and make your own boards.)

I think the "sonar sensor" is the most egregious, such a thing it $1 in parts but is retailed at $25. That is just ridiculous. The obvious solution was to use a Raspberry Pi instead, it might even be able to emulate the sonar ranging algorithm on the CPU.

I think you can get one of those sonar sensors for $6 on amazon. They're cheap. I don't think the obvious solution is to use a general purpose computing machine...

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