Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Building an occupancy sensor with a $5 ESP32 and a serverless DB

matthew.science

Post reply on HN
Print view View original

61–70 of 221 posts

Re: Building an occupancy sensor with a $5 ESP32 and a serverless DB

#61

Post by kps »

davidw wrote: post #57
lostapathy wrote: post #53

Earlier quoted context omitted.

As somebody else mentioned, you can hire it out. There's a lot of files running around with existing models for common projects, so you probably don't need to design your own enclosures a lot of the time unless you want to. And printers have gotten cheap, like $99 gets you a jumping off point into the hobby.

Do people not just sell like "complete package" things? The board in the article is $13.49 ( https://www.amazon.com/dp/B072HBW53G ). If you could get an enclosed, complete thing for $20, including the board and whatever you need for it to run, that'd be much less of a PITA than "brand new hobby" or "find someone to 3D print stuff for me locally and deal with that whole hassle".

There are things like M5Stack (also ESP32-based) that suit some purposes.

Re: Building an occupancy sensor with a $5 ESP32 and a serverless DB

#62

Post by fnordpiglet »

While I don’t discourage learning a new language the immediate toss aside of rust on esp32 was perplexing. It sounds like a lot of the memory issues would have been mitigated by sticking with a language better understood. Rust’s esp32c3 support is pretty good IMO, that’s all I use. Writing in C++ makes me feel dirty in ways that even COBOL doesn’t.

I also think I would have implemented presence by TTL, updating the TTL for each MAC when I see it and purging a TTL heap before updating my remote statistics. I didn’t fully grok the approach taken for maintaining the hash map, in a taxi off a long flight, but it didn’t seem super robust on my quick read.

Re: Building an occupancy sensor with a $5 ESP32 and a serverless DB

#63

Post by chpatrick »

morphle wrote: post #60
davidw wrote: post #43

How do people "productize" their ESP32 projects? (Edit: not talking about mass-producing something, I just want a self-contained unit rather than a board with a bunch of wires sticking out) I see a lot of pages where they show some bare-looking board, but in the real world you want to package that up. If you're a software guy like me, you would likely prefer to pay a bit extra to just have that tidied up for you rath…

You shouldn't productise anything with ESP32, its just an overprized bloated hobby pcb. See my comment below on how to productize this: use a 4 cent off the shelf microcontroller on a 10 cent pcb or much better: make a custom chip with all the sensors on board but with $25K minimum Capex but tiny Opex

There are thousands of ESP32-based IoT devices on AliExpress that would disagree with you. It's an SoC chip not a "pcb".

Re: Building an occupancy sensor with a $5 ESP32 and a serverless DB

#66

Post by morphle »

morphle wrote: post #60
davidw wrote: post #43

How do people "productize" their ESP32 projects? (Edit: not talking about mass-producing something, I just want a self-contained unit rather than a board with a bunch of wires sticking out) I see a lot of pages where they show some bare-looking board, but in the real world you want to package that up. If you're a software guy like me, you would likely prefer to pay a bit extra to just have that tidied up for you rath…

You shouldn't productise anything with ESP32, its just an overprized bloated hobby pcb. See my comment below on how to productize this: use a 4 cent off the shelf microcontroller on a 10 cent pcb or much better: make a custom chip with all the sensors on board but with $25K minimum Capex but tiny Opex

As others point out: you could hire someone to do it. Based on my custom 1 cent ASIC (custom chip) I would design, test and build your (moisture or other) sensor for €3000 excluding tax and price of all the needed tools. Usually more like $6000 because they want to outsource all the problems (like mass production and sales) to me

morphle@ziggo.nl if you want me to design it

Re: Building an occupancy sensor with a $5 ESP32 and a serverless DB

#67

Post by davidw »

bluGill wrote: post #59
davidw wrote: post #47

Earlier quoted context omitted.

That sounds like one of those "I have a problem... now I have two problems" jokes. I wanted something simple and cheap and now I need to go deal with this whole other thing I don't know much about and either rent or buy into it?

That is why so many amateur projects look ugly: making a pretty package is a whole new skill set. 3d printing is the easiest acceptable solution, but it isn't the best. Best would be a custom designed injection molded housing, but that is even more work to design. Nothing about making a nice presentation is beyond what amateurs can do. However it is a lot more effort and so most decide it isn't worth it.

I don't care if it's "beautiful" or ultra-compact or looks as nice as some Apple device. All I want is to buy one thing without wires and an exposed board.

Re: Building an occupancy sensor with a $5 ESP32 and a serverless DB

#68

Post by szundi »

j1elo wrote: post #64

Always surprised to see people running around with their Bluetooth needlessly enabled. Maybe I worry to much about battery usage, but I just got used to always enable WiFi, Bluetooth, or NFC, only at the moment of usage, and disabled afterwards.

Google/Apple obfuscating these mac addresses do not help anymore?

Re: Building an occupancy sensor with a $5 ESP32 and a serverless DB

#69

Post by ThrowAway1922A »

j1elo wrote: post #64

Always surprised to see people running around with their Bluetooth needlessly enabled. Maybe I worry to much about battery usage, but I just got used to always enable WiFi, Bluetooth, or NFC, only at the moment of usage, and disabled afterwards.

I have a smartwatch and airpods, turning off Bluetooth would cause both not to work.

I'm more surprised that anyone ever turns it off, battery use is negligible compared to the cellular modem as I browse the web/listen to music.

Re: Building an occupancy sensor with a $5 ESP32 and a serverless DB

#70

Post by davidw »

kps wrote: post #61
davidw wrote: post #57

Earlier quoted context omitted.

Do people not just sell like "complete package" things? The board in the article is $13.49 ( https://www.amazon.com/dp/B072HBW53G ). If you could get an enclosed, complete thing for $20, including the board and whatever you need for it to run, that'd be much less of a PITA than "brand new hobby" or "find someone to 3D print stuff for me locally and deal with that whole hassle".

There are things like M5Stack (also ESP32-based) that suit some purposes.

Yes! That looks pretty cool and more like what I'm talking about.
Post reply on HN