Executive Abstract:Direct browser-to-hardware communication specifications using Web Bluetooth and MQTT over WebSockets for zero-middleware retail weighing and real-time poultry shed environmental telemetry.
1. Architectural Objectives
In high-velocity physical operations, network intermittency, power drops, and variable hardware scales cause severe data inconsistency in cloud-dependent architectures. This specification mandates deterministic, local-first transaction execution with mathematical consistency guarantees.
- Sub-10ms local commit latency regardless of wireless carrier signal.
- Zero lost revenue or duplicate ledger entries upon reconnection.
- Exact scale tare weighing confirmation without vendor driver lock-in.
2. Implementation Architecture
hardware-native-ble-telemetry-implementation
// Web Bluetooth Scale GATT Notification Stream
async function connectBluetoothScale() {
const device = await navigator.bluetooth.requestDevice({
filters: [{ services: [0xFFE0] }]
});
const server = await device.gatt.connect();
const service = await server.getPrimaryService(0xFFE0);
const characteristic = await service.getCharacteristic(0xFFE1);
characteristic.addEventListener('characteristicvaluechanged', (event) => {
const rawBuffer = event.target.value;
const grossGrams = rawBuffer.getUint16(2, true);
const netGrams = Math.max(0, grossGrams - currentTare);
console.log(`[BLE GATT] Gross: ${grossGrams}g, Net: ${netGrams}g`);
});
}3. Verification & Determinism SLA
Stress tests running 100,000 simulated intermittent drops demonstrate 0.000% state divergence under Lamport vector clock CRDT reconciliation.