Project Title:Android App with Weighing Scale Integration for Food Manufacturing Operations

Location: Naraina, Delhi

Project Type:One-time project (with potential for ongoing enhancements)

Platforms:Android tablets (factory floor use)

Industry:Food manufacturing / food processing

Project Overview

We need an Android-based application that connectsweighing balances to factory tabletsand digitizes key parts of our production workflow:

Raw material intake
Batch/recipe processing
In-process checks
Finished goods packing
Inventory updates & basic traceability

The app must read live weights directly from connected weighing scales and push validated data into our backend (ERP/DB/API), replacing manual entries and paper records.

2. Scope & Key RequirementsA. Weighing Scale Integration

The app should:

Support integration with standard industrial weighing balances connected to tablets via:
RS232 ? USB converters, or,
USB, or
Bluetooth / Wi-Fi(depending on device capabilities).
Continuously read stable weight values from the scale.
Prevent manual override of measured weight (configurable).
Handle:
Tare / zero
Gross / net readings
Unit conversions (kg/g)
Provide adevice configuration screen:
Select COM/USB port (where applicable)
Baud rate, parity, stop bits, etc.
Test connection & view live readings

We're specifically looking for someone who has already worked withserial/USB/Bluetooth deviceson Android.B. Core Functional Flows

We want simple, robust flows operators can use on the shop floor:

Raw Material Inward

Select PO/supplier/material (from local cache/API).
Read weight from scale ? confirm ? create entry (gross, tare, net).
Capture batch/lot number, date, optional photo, signatures.
Sync to backend.

Batch / Recipe Weighing

Select production order / recipe.
Show required ingredients & target weights.
For each ingredient:
Read from scale
Validate within tolerance (e.g. 2%)
Color-coded feedback (OK / Under / Over)
Log who weighed what, when, and final values.

Packing / Finished Goods

Select product + pack size.
Read net weight from scale.
Confirm or reject (if out of tolerance).
Increment packed quantity & update inventory.

Inventory View (Basic)

View key material and FG stock levels (from backend).
Search by item / batch / location.

Audit Log

Store timestamped events:
User, operation type, material, batch, weight, station.
Viewable on tablet (filtered).
Synced to backend for traceability.

C. Technical & Functional Requirements

Tech stack:Native Android (Kotlin/Java) or Flutter/React Native (open, but must justify for device IO).
User roles & auth:
Simple login (PIN/password).
Role-based access (Operator, Supervisor, Admin).
Offline-first:
Must work when network is down.
Queue & sync data securely once back online.
Backend integration:
For this phase: useREST API layer(we will provide or design with you).
App should be structured so it can integrate with ERP later (Odoo / other).
UI/UX:
Optimized for1012 Android tablets, landscape mode.
Big buttons, high contrast, minimal steps.
Operator-friendly, low text input.
Security:
Local data encryption preferred.
Secure API calls (HTTPS, tokens).
Code quality:
Clean, modular, documented.
Hand-over must include full source code, build instructions.

3. Deliverables

Requirements clarification + brief technical design.
Clickable UI mockups for main flows (in Figma or similar).
Android app with:

Working weighing scale integration (demo with at least one real protocol/model or simulated mode).
Implemented flows: Inward, Batch Weighing, Packing, Inventory View, Logs.

Configurable API endpoints & environment settings.
Basic admin configuration:

Users, tolerance limits, stations, materials mapping.

Source code + documentation:

Setup guide
How to add support for new scale models
API contract

Support for initial bug-fixing after go-live (short warranty period).

4. Required Experience

Please apply only if you have:

Strong Android development experience.
Proven work integratinghardware devices:
RS232/USB serial, Bluetooth, or similar.
Experience with at least one of:
Industrial / manufacturing / logistics apps
Weighing scales, POS, barcode scanners, or IoT on Android.
Solid understanding of:
REST APIs, JSON
Offline data sync
Basic security best practices

Nice-to-have:

Experience with food / pharma / manufacturing traceability.
Familiarity with Odoo / ERP integrations / MES / SCADA.

5. What to Include in Your Proposal

Please include:

Short intro: your experience with Android + hardware/scale integration.
23 relevant project examples (screenshots or links).
Which approach you'd use for:

Serial/USB/Bluetooth communication on Android
Offline data + sync

Rough estimate:

Timeline (phased: MVP + refinements)
Cost (range is fine at this stage)

Any assumptions / suggested improvements to our flows

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