How we built a Smart Office system based on Raspberry Pi
In this technical retrospective (2016), @dragonbonheur shares practical architectural lessons learned from running, scaling, or migrating production software under lean constraints.
Core Principles for Independent Builders:
Defaulting to simpler architectures (such as monolithic frameworks, SQLite, or managed VPS) prevents early engineering bankruptcy.
Evaluating true compute and egress costs reveals that high cloud bills can often be slashed by 80%+ through judicious re-platforming.
Code you write at 2 AM as a solo engineer must be easy to debug six months later without complex microservice dependencies.
Community Debate Themes:
HN engineers debated the tradeoffs between cloud convenience and raw server economics, database indexing strategies, and resisting premature architectural complexity.
CATEGORY Frugal Engineering →
HISTORICAL ERA Cloud & Mobile Era (2014–2019)
COMMUNITY SCORE 200 points
TOTAL DISCUSSIONS 63 comments
Yay, this is my world! Looks like a super nice homebrew solution.
I don't think I've ever used or worked on a project with PLC's handling any sort of core logic though. Sure they'll occasionally run small components of simple edge systems (HVAC, lift motor control, physical access etc) but the overwhelming majority of systems are built with a network of embedded controllers. Any systems rolling out today will (or at least should) then combine this with some server side backend for analytics and shifting interaction logic away from the the edge systems to somewhere it's a little easier to change and adapt to the needs of the building.
There's some pretty established, older players (Crestron, AMX et al) that make full programmable solutions, but by all modern standards their development tools are atrocious - you'd need to be a complete and utter masochist to want to enter that world today.
The good thing about this is a bunch of amazing people building well designed, open source and non-proprietary solutions to make this world suck less.
My two favourites are http://nodel.io/ ↗, which runs a fully distributed architecture (and can even have the nodes running of RPi's) and http://www.acaprojects.com/ ↗ which is a keeps all the system logic server side.
A DIY-solution is nice (and as engineers something really fun to do) but they will have to maintain it in the future and this is not necessarily "future proof". They would have simply put some KNX[0] compatible components in the system, they would have had control of everything using an open standard. They could have connect light, security cams, door locks, the power plugs, etc... and because this is a standard, the day they move out of the office, they will be able to resell the system to the next users.
[0]: https://knx.org ↗
Good to see in a DIY-solution:
(I wish they'd explained how they do it, but I assume they use latching relays to switch the actual lights, so RPis and light switches can work in parallel)
Using the chrome debugging protocol for the remote screens is also quite clever.
That's like saying "How we built a Smart Office system based on Electricity", the RPi is just any old single board computer here with some GPIOs.
In any case, I sure hope they have mounted their SD cards as read-only, because otherwise they might find their keycard system not working one early morning in approximately a year or 2-3 random power off events. Theres a reason for these PLC systems after all.
Fun to see someone do this with the pi.
I wonder how they handle security. Especially since it also controls access to the facility.
Also, would be pretty funny if the RPis went all Hall one day.