i-Power Engine ／ Development Collaboration
HACHIDORI SOLAR

Development Role Split

Thank you for a productive discussion. This document organises the “A+” direction we agreed together, laid over UB BOX's own system architecture, with each area colour-coded by who develops it. We hope it serves as a helpful basis for UB BOX to prepare a development schedule and estimate.

Agreed on the A+ direction
IoT platform: source disclosed
Target: beta launch, Mar 2027
01 · Role Map
UB BOX architecture × who develops what
Hachidori — in-house UB platform, in Hachidori's cloud (source disclosed) UB BOX — HW + FW To define (license scope)
① App Layerruns on phones & browsers
Business Front-endHachidori
User App Installer App Service Provider Web Master Admin Web
② Cloud Layerruns in Hachidori's cloud
Business BackendHachidori
Site Mgmt Service Provider Mgmt O&M Mgmt Installer Mgmt Smart Strategy Data Electricity Price Data Device Data Device Control
StrategyHachidori
Your Strategy ✓ (chosen) UltimateBox Strategy — not used
UltimateBox Service VPP · forecasting · pricingTo define
VPP Revenue VPP Resource Mgmt VPP Dispatch Mgmt Energy Forecasting PV Forecasting Dynamic Price Data Device Energy Data Subscription Mgmt
Control, VPP and forecasting are UB BOX's strength. In line with the “A+” approach, we would license this IP & know-how from UB BOX; the exact split — what UB BOX provides and what Hachidori builds — is something we'd like to define together, alongside the estimate.
IoT PlatformBuilt by UB BOX + open source
Thing Model Mgmt Protocol Mgmt Network Component Mgmt Data Uplink / Control Downlink
Built by UB BOX Runs in Hachidori's cloud Source disclosed ★ (agreed)
With the source disclosed, both teams share one clear foundation, and we can operate it with confidence inside our own environment — a stable basis for a long-term partnership.
To confirm The functions above are described at a high level, so we'd like UB BOX to share the detailed scope of what is actually included.
▲ Interface: OpenAPI & OAuth 2.0 (business API) · MQTT (device data / function calls) — cloud ⇄ edge ▲
③ Hardware + Firmware (Edge)runs on the device
Firmware has two layers. The functions we've shared so far (below) are the App Layer. What we most want to align on is the layer beneath it — the Device Control Layer (the embedded software that drives each chip) — and how much of it UB BOX can develop.
Firmware · App LayerUB BOX · shown
Chargeable/Dischargeable Power Calc Data Cleaning Control Priority Safety Alarm Safety Strategy Exec Smart Strategy Exec
Firmware · Device Control Layer★ the core question
The layer of embedded software that drives each communication / security chip. Because the implementation changes with the chip chosen, maker selection and a feasibility judgment must be made carefully.
likely OKWi-Fi / BLEMurata Type 1YNGeneric Wi-Fi5 + BLE5.0 combo module (SoC: SDIO / UART4). Standardised worldwide, so we understand this is not an issue.
keyWi-SUNROHM BP35C0-J11-T01Not generic — the driver is chip-specific. Our current choice is ROHM BP35C0-J11-T01 (driver = ROHM J11 protocol over UART2; 2nd source: Lapis ML7396C). We'd like to confirm whether UB BOX can implement this driver — or propose an alternative chip if preferable.
confirmLTEQuectel EG915Q-JPSelected chip: Quectel EG915Q-JP (Cat 1 bis, SoC: USB2.0 / AT; Giteki / JATE / TELEC done). Mainstream in Japan, though Europe tends to be wired-based. Can UB BOX obtain this module and implement its driver (USB / AT / PPP)?
securitySecurity SEInfineon OPTIGA Trust M V3Secure element driver (SoC: I2C 0x30, ECC256; 2nd source: NXP SE050).
Full firmware stack (from the HW spec): U-Boot (secure boot) → Linux 5.10/6.1 LTS (Yocto) → drivers for each chip → app layer (ECHONET Lite / Wi-SUN stacks). We'd like to align on how much of this whole stack — boot, kernel and drivers included — UB BOX can take on.
▶ We'd like to align on how much of this hardware-side Device Control Layer UB BOX can take on.
HardwareUB BOX
Gateway (NXP i.MX 8M Mini) ECHONET Lite / Wi-SUN support (UB confirming)
Devices to integrateVarious makers
Inverter Heat Pump EV Charger Meter
🔺 Cross-cutting requirement: JC-STAR compliance is carried across every layer — hardware, firmware and cloud.
02 · Status & Next Steps
What's agreed, and what's still open

✓ Agreed in the meeting

  • Hardware + firmware are developed by UB BOX
  • Cloud + apps are built in-house by Hachidori
  • UB's IoT platform runs inside Hachidori's cloud, with source disclosed
  • “Your Strategy” (Hachidori's) is the chosen strategy layer
  • Development proceeds on the assumption of JC-STAR compliance

◷ Still to define

  • Whether ECHONET Lite / Wi-SUN can be supported (UB confirming)
  • How much of the firmware Device Control Layer (embedded software for the Wi-SUN / LTE / security chips) UB BOX can develop
  • The detailed scope of the IoT platform functions (currently high-level) — to confirm with UB BOX
  • The license split for the UltimateBox Service layer (VPP · forecasting · pricing)
  • Detailed spec of the interface (OpenAPI/OAuth · MQTT)
  • Schedule and estimate toward the March 2027 beta