Three-Phase Smart Energy Meter — Metering IC to Cloud
Description
A complete three-phase smart energy meter, taken from hardware architecture through firmware to the cloud backend that receives the data. One vendor across the whole stack, rather than a board handed to a separate firmware team and a separate backend team.
Stack
- ATM90E36A three-phase metering front-end — voltage, current, power, energy, and harmonics
- ESP32-S3 application processor
- Quectel EC200U cellular modem for backhaul where there is no local network
- CC2652P Zigbee radio for local mesh to neighbouring meters
- Server side: MQTT broker, time-series storage, dashboards
Engineering Constraints
Mains-referenced measurement alongside low-voltage digital. The metering front-end sits on the mains side while the processor and radios do not. Creepage and clearance are layout constraints, not annotations — they set the placement before routing begins.
Two radios on one board. Cellular and Zigbee share an enclosure and a ground. Antenna placement, keep-outs, and supply decoupling were resolved at layout rather than patched afterwards with shielding.
Accuracy is the product. A metering board that reads slightly wrong is worse than one that fails outright, because nothing announces the error. Reference and burden component selection were treated as accuracy decisions, not BOM line items.
Documented Architecture
The hardware architecture was issued as a controlled document with its own identifier, covering the power tree, GPIO allocation across processor and both radios, and the interface map between metering front-end, processor, and backhaul.
The client owns that document. It can be handed to another engineer without a conversation — which is the point of writing it.
Deliverables
- Hardware architecture document under formal revision control
- Schematic, layout, and fabrication package
- GPIO and peripheral allocation map
- Firmware through to data reaching the broker
- Backend ingestion, storage, and dashboards
Published without client, project name, or location under NDA. Silicon and architecture are unchanged.