Mobile Application Developer

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:

1. 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.

1. 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.

1. Packing / Finished Goods

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

1. Inventory View (Basic)

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

1. 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

1. Requirements clarification + brief technical design.
2. Clickable UI mockups for main flows (in Figma or similar).
3. 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.

1. Configurable API endpoints & environment settings.
2. Basic admin configuration:

• Users, tolerance limits, stations, materials mapping.

1. Source code + documentation:

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

1. 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:

1. Short intro: your experience with Android + hardware/scale integration.
2. 23 relevant project examples (screenshots or links).
3. Which approach you'd use for:

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

1. Rough estimate:

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

1. Any assumptions / suggested improvements to our flows