Looking for advice on DIYing a Multi-sensor

Hi, so I accidentally stumbled down the Home Assistant rabbit hole this week and got HAOS up and running on a Pi4 and integrated with my Google Assistant and got my dashboard kind of set up how I think I want it for now so now I’m looking to add some sensors for light control and security purposes as well as general living condition data.

My cart on AliExpress currently has these sensors:
10 x AHT 20 Temp/humidity
2 x AHT 25 Temp/humidity
5 x DHT 22 Temp/humidity
8 x BME 680 Temp/humidity/pressure/VOC
10 x RCWL-0516 MW radar
3 x HFS-DC06 MW radar
10 x AM 312 PIR
10 x Photoresistors (https://www.aliexpress.com/item/1005005066273808.html?spm=a2g0o.cart.0.0.202b38da2yC7O6&mp=1)

Lastly I’ve got 10x ESP32-C6 Boards (8MB version here: https://www.aliexpress.com/item/1005005720674915.html?spm=a2g0o.cart.0.0.202b38da2yC7O6&mp=1) in the cart I’m hoping to use to make my sensors

Ultimately, I’d like make 6 indoor multi-sensors that detect movement via the PIR,MW, and onboard bluetooth sensors using ESPhome and I’d like those sensors to also control lights (if needed) using the lux sensors as well as give me fairly accurate temperature/humidity readings. I’d like 2 of those sensors (at minimum) to give pressure and 1 of those 2 (also at minimum) to also give VOC readings. I’d love to add a camera to each of these as well but I feel like I have to be getting close to the capacity of what these boards can handle if I haven’t already exceeded it.

I plan on putting 1 sensor in my 3d Printer’s enclosure that can measure temp/humidity/VOC

And finally I’d like to make 1 more sensor for outside as a weather station that I’ll eventually turn into this: https://www.instructables.com/DIY-Weather-Station-With-ESP32/ but I live in an apartment and that whole unit will look ridiculous on my balcony. So I’m fine with just the basics (temp/humidity/pressure) to start, and I’ll slowly upgrade as my neighbours get used to it. I do live in Southern Ontario so temperatures occasionally get cold in the winter and I want to make sure there wont be any durability problems keeping it one of them outside.

So as you can see there’s quite a bit of overlap with those sensors lol. Accuracy is my primary priority with this project. I’d welcome any advice on if there are any parts I could remove from my cart or if there are parts I should maybe think about adding or substituting (for example the ESP32, I couldn’t find much info on the C6 variant and I want to make sure it can power everything). I might even keep some of the parts in the cart for future projects (Definitely don’t think I need all those temp/humidity sensors if some are clearly better than others with no benefits though) so feel free to make suggestions about any other sensors/parts I might want to purchase for the future so I can stock up and don’t have to wait on AliExpress shipping a bunch of times.

It might be an idea to look at a pre-made solution at least as a starting point.

Well that kind of takes the fun out of the DIY process, doesn’t it? I wound up getting what I planned but got the ESP32 S3 boards (16MB) and dropped the DHT22s. I might upgrade to the C6 when it’s fully supported and I see what kind of thread integration there is, but at this point I don’t think I have anything to gain getting the C6 to start aside from maybe saving a few dollars in the future at the cost of my sanity trying to figure the board out before it’s supported now.

Still open to suggestions for any additional sensors or parts anyone thinks I might want in the future!

Yeah look, I’m all for DIY and have built a number of things myself, but sometimes it’s just not worth it when something really good already exists at a good price.

I must be missing something, because I keep seeing people recommend this sensor… for $80.

I’m fully supportive of helping the community along by supporting these innovators that provide so much back, but that’s just completely unaffordable to outfit multiple rooms with.

No other smart switch, outlet, dongle, board in my house approaches that price. I have raspis cheaper than that!

Please tell me how that is worth it. I’m totally genuine here - I don’t understand how it’s worth the cost.

if someone is looking for an all in one multisensor, $80 is competitive to the z-wave based competition of pre-manufactured multisensors. The aotec multisensor 7 is right at the same price point. The sensors alone in the $80 everything sensor without shipping, soldering, or any level of assembly would run you around $55 as it is.

Not saying that folks don’t find utility in doing all their own soldering with their own custom parts list, but that is kinda the trade off, no? Everything you want and some things you don’t need for more money than if you did all the sourcing and assembly yourself but you can save yourself a few hours to days depending on skill level or available time to actually build out a sensor from scratch.

The OP was saying that they wanted to build something out from scratch though, so buying that sensor does seem less like what they might want.

To be fair and transparent, $30 of that parts list is the also-overpriced mmwave sensor. When the next best sensor is $2.87, and this multi device also has a PIR for the same purpose, its hard not to question the price.

If you want the Cadillac of multi sensors, with zero effort, you’re the perfect customer. If you’ve set up HA and started tinkering, it’s probably not you. Unless you also just like the absolute cutting edge widgets and have cash to burn.

I’m also a frugal diy curmudgeon, who wants devices in every room, so the price alone is a nonstarter even if it was made of gold.

yeah, that’s fair, I don’t really disagree with this