PHOA is a two-tier ESP32 system for getting your utility water-meter reading into a database in real time. A Node device locks onto the meter you own and reads it over the 900 MHz ISM band; a central Gateway aggregates the readings from one or more Nodes over a 433 MHz mesh and uploads them to a PC ingest service on the local LAN.
Hardware is off-the-shelf Heltec / CT62 ESP32 boards plus SX1276 / SX1262 FSK radios and a CC1101 mesh transceiver. Firmware is proprietary, with updates delivered over the air. Each Node is scoped to a single owner-configured meter (see Privacy by default). The dashboards shown below are live; every number is real telemetry captured from the running deployment.
Utility billing arrives once a month. Between cycles, you can’t see a stuck-open valve, a broken irrigation line, or a slab leak; you only learn about it when the bill shows up with an unexpectedly large total. The conventional alternative, retrofitting outlot irrigation controllers with their own integrated flowmeters, carries substantial equipment and installation costs per zone.
PHOA reads the utility’s own meter wirelessly, with no plumbing changes. Consumption patterns build up over time per meter, so sudden out-of-range conditions stand out before they become an invoice. Line breakage and runaway irrigation are caught while they are still leaks, water is saved, and the end-of-month bill holds no surprises.
The 900 MHz band is shared, so a receiver in range can physically hear many utility meters. PHOA deliberately does not act on that. Each Node is bound to one default meter, the meter owned by the customer who installs it, and in normal operation the dashboard, the JSON API, the email reports, and the upload to the database surface only that meter. Every other meter the radio happens to hear is withheld at the source.
Seeing the full in-range list requires a debug mode gated by the device's access-point password and held in RAM only, so it is off after every reboot. The result: an operator collects, displays, and stores only their own consumption data, which keeps third-party utility data, and the liability that comes with it, out of the system. More on the Node page.
Locks onto the utility meter its owner configured and decodes its RF readings. Supports three meter protocols, shows that one meter live on an embedded dashboard, and relays it to the gateway over a long-range 433 MHz mesh link. Other in-range meters are withheld unless debug mode is unlocked.
Read about the Node
The mesh hub. Listens on 433 MHz for readings forwarded by Nodes, queues them locally if the PC is offline, and POSTs them to a Windows ingest service on port 41290. Hosts a fallback WiFi AP so distant nodes can always phone home.
Read about the Gateway
Reading flow is one-way: meter → node → gateway → PC. Commands flow the other way over the same mesh.
The same Node firmware supports two install patterns. For large or distributed sites, multiple Nodes feed one Gateway over the 433 MHz mesh and the Gateway uploads to a central database. For small clusters (a single building, a small park, one property), a Node can run standalone on local WiFi, with its own dashboard and daily emails; no Gateway is needed. What changes between the two is only whether the mesh is in use.
This site is designed to be machine-readable. Structured device specs are available as JSON; a top-level llms.txt indexes the pages.