ISV IEEE Smart Village
← Meter Interoperability · OpenAMI

MeshEMS board

NESL · OpenAMI-aligned · multi-tenant edge metering · workshops & field deployments

Board diagram

NESL EMS Controller PCB 865B — annotated diagram with ESP32-S3, Ethernet, RS485 Modbus, TFT display, SD card, and SSR headers
NESL EMS Controller PCB 865B — basic board diagram (Rev 001). ESP32-S3; HanRun Ethernet; HW-519 RS485 (master Modbus/RTU); 128×128 TFT (SPI); SD card; onboard SSR headers; ext 5 V / 3.3 V inputs; GPS and door-switch I/O. From energy-iot/meshems-openami-metering · NewEnergySolutionsLab.com.

Bill of materials (BOM)

Living parts list for the NESL 865B MeshEMS / Street-EMS dev kit — components, sources, and workshop kit quantities. Maintained in Google Sheets (view access; request edit from NESL / Energy IoT if you are building kits).

MeshEMS board BOM (Google Sheets) ↗

The MeshEMS board is an ESP32-based EMS PCB designed by NESL in alignment with OpenAMI — mesh-capable neighborhood-area networking for DCU backhaul when pole-to-pole RF redundancy is needed. OpenAMI metering firmware targets the NESL 865B: meshems-openami-metering.

OpenAMI alignment

Modbus RTU meters (DDS238, CHD130, DDSU666) or CircuitSetup ATM90E32 6-channel SPI; MQTT northbound; SSR load control. Schematic: nesl-meshems · BOM.

Why this board exists

A multi-tenant edge metering system — one pole gateway for several customer circuits (~6 homes or loads) with clear separation of what belongs upstream vs downstream of the revenue meter. Used in workshops, hackathons, and field deployments; documented in the open so communities can reuse the lessons and develop technological autonomy early during rapid load growth.

Upstream · meter · downstream

A practical first step is to clarify and isolate knowledge on each side of the revenue meter. MeshEMS sits at that boundary and makes interoperability visible — what the DCU must speak upstream versus what each customer circuit needs downstream.

Upstream of the meter

  • DCUs and pole gateways
  • Utility / feeder systems
  • Head-end, vending, operator backends
  • Northbound MQTT · geo asset model

Downstream of the meter

  • Multiple homes and customer circuits (~6 per board)
  • Per-tenant reads, credit, disconnect
  • Branch loads, anchor tenants, theft visibility
  • Off-the-shelf meters and SSR control

← revenue meter / gateway normalization →

OpenAMI · OBIS · building in the open

OpenAMI — actionable telemetry and leakage visibility (feeder → branch → customer). OBIS · VMRS — shared register semantics northbound. ISV curates workshop notes, gap matrices, and distribution lists in alignment with EnAccess, Energy IoT, NESL, and field operators.

Role in the stack

LayerMeshEMS
SouthboundDLMS / OEM meter interfaces via gateway firmware; pairs with CircuitSetup and other bench/field meter boards.
EdgeESP32 EMS — mesh NAN between DCUs; optional when a single Street Pole gateway is not enough for feeder coverage.
NorthboundMQTT / JSON registers aligned to OBIS · VMRS — same OpenAMI contract as EnAccess MPM and operator backends.
Firmwaremeshems-openami-metering (865B · OpenAMI) · ems-dev (Street Pole EMS)

Events & deployments

MeshEMS is a shared platform — not built for a single conference. Scheduled and in-flight uses include:

MeshEMS vs Street Pole EMS

Street Pole EMS — single-pole ESP32 gateway prototyped at the 2025 Open Energy Hackathon; live metering, SunSpec telemetry, MQTT northbound.

MeshEMS — NESL PCB variant with mesh backhaul so multiple DCUs can form a neighborhood-area network when line-of-sight or single-hop RF is insufficient. Use when the OpenAMI deployment needs redundant pole-to-pole links, not when a standalone pole gateway is enough.

Power rails (workshop)

Bench and field kits need planned 5 V and 3.3 V rails — see 25 Jun 2026 notes · MeshEMS power architecture.

ISV wiki threads

External links