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Comment by ahaucnx | Hacker News Reader

Very interesting read. Based on our experience developing and manufactoring air quality monitors, making a customized PCB should be done as early as possible in the developing process.

With easy to use editors (e.g. easyEDA) and cheap and fast PCB production/assembly (even for small quantities), there is no reason to use overized MCUs/mini computers like the Pi and expensive modules e.g. from Adafruit.

Also, BOM components selection is key. For the same functionality, e.g. a multiplexer there are many different chips available -often at very different price points. Availability in times of chip shortages are also key to keep an eye on.

Technically this product is very simple and the BOM costs they had were a magnitude too high. Too bad because it seemed that the market was ready and they could have become a very successful business.

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> there is no reason to use overized MCUs/mini computers like the Pi and expensive modules

There is if you don't have the expertise. Of course, arguably if that's the case, you shouldn't be developing such a product anyway. But as the post detailed, by switching to a Pi Zero and removing the Adafruit HAT, the BOM costs would already drop significantly. I think if you're smart about it, you absolutely can build a viable product this way. Certainly not as profitable, but possible.

I’ve been working on a hobby project for about 6 years, and early on I got very excited about productizing it. It led me down some interesting paths and really made me think about overall BOM cost, designing for assembly, ease of use, etc. It also revealed some weaknesses for me, as I kept making decisions based on something I was sure I could figure out, rather than what I actually knew how to do.

Eventually I switched some things up and it got much easier.

I'd read this article!

As would I!

All of this presumes that the person making these costs $0 per hour. Turning hobby into a business is rarely a successful scenario.

This screeches to a halt, the moment that you put into perspective. My typing this is equivalent to a few dollars, because most people here have at least $50 per hour engineers. Designing PCBs for existing modules(ex. ESP32) takes a very long time(and a lot of knowledge) and it's not just "put this chip here and have software figure it out".

"there is no reason to use overized MCUs/mini computers like the Pi and expensive modules e.g. from Adafruit."

Definitely not for scaling, but for deploying prototypes this approach is awesome! Eg use the Pi to create some prototypes, get user feedback, launch a kickstarter, do what you said. I worked at robotics startup that did this, worked super well for our first robots. Podcast about it: podcasts.apple.com/us/podcast/erik-schluntz-cobalt-robotics/id1649845905?i=1000584727151

How difficult would it be to run a Linux operating system on this custom PCB, allow for Wifi connectivity, etc to provide for the features the product provided. Like the wifi-setup, it having internet connectivity, ability to poll an API, etc.

Genuinely curious, as I've typically used things like the Pi for projects like this but have been genuinely curious what it would take to strip it down to something less powerful and achieve the same result.

I’m making a project with a pi pico and it will have to do all of that. It already sends an update to the server per second with wifi. A full raspberry pi is over kill for most of these projects.

A Raspberry Pi Pico W is a microcontroller (no operating system) that incorporates Wifi. The way it works is you write a program that runs in a loop and talks to the GPIO ports or whatever. It's incredibly simple and it all runs from flash, so no operating system or anything else needed. They cost less than AUD 10 (about 7 US-bucks)

https://raspberry.piaustralia.com.au/products/raspberry-pi-p...

Since I am a Go developer, I like using TinyGo with these type of boards, which means I get concurrency (goroutines) as well, although sadly Tinygo doesn't yet support the Wifi module. However, I've used other boards with Wifi, and once you're connected to WiFi you can poll APIs and do anything else you do on the internet. No OS required!

As an example of a complete, stand-alone program, I wrote a digital clock in TinyGo. (https://github.com/doctor-eval/clocky) - you plug the Pico into a 7-segment display and it operates just like an old school digital clock.

Sadly it can't (yet) connect to the internet due to missing wifi support in Tinygo, and it's running on a pre-W Pico, but you get the idea.

If you are OK with FreeRTOS instead, then it's even cheaper.

The cheapest you can get is about $5(Espressif assembled board), with full LED matrix controller.(that's the cost of manufacturing, though)

a full blown Linux stack is $10+

This further hits home the lack of business acumen of the founders. Let's assume BOM is an order of magnitude off -- 10x what it should be. That doesn't mean fixing the problem would 10x profits. It would merely reduce BOM by 10x. Thus, if you can sell the thing for $600, you actually 20x Profit!

Missed opportunity by this startup.

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