CASE STUDY / 01

Industrial Batch
Controller

A Raspberry Pi based industrial dispensing controller designed to integrate load cells, solenoid valves and pumps with touchscreen HMI into one embedded system.

ROLE Software & Embedded Developer

PLATFORM Raspberry Pi / Embedded Linux

STACK C++ / Qt / Modbus RTU

Load Cells controller with touchscreen HMI running on Raspberry Pi

Load cell based weight measurement

Overview

The system is an embedded industrial controller for automated liquid dispensing. It combines a touchscreen user interface, load cell communication, GPIO pump and solenoid valve control, transaction management and thermal printing.

The application runs directly on Raspberry Pi with Embedded Linux. Qt and C++ provide the HMI and application logic, while Modbus RTU is used to communicate with the industrial load cells.

The Problem

The dispensing process requires coordination between instrumentation, valves, pumps and the operator. The controller needs to react to real-time flow conditions while keeping the user interface simple enough for industrial operation.

01 Real-time measurement

Accurately measure material weight using load cells for precise dispensing control.

02 Process control

Control high-flow and slow-flow dispensing stages.

03 Reliable operation

Handle no-flow and communication timeout conditions.

04 Transaction traceability

Record batch and dispensing information for later use.

SYSTEM DESIGN

Architecture

The controller sits between industrial field devices, machine actuators and the operator interface.

FIELD DEVICES MK-Cells MK-D18+ Modbus RTU / RS485

EDGE CONTROLLER Raspberry Pi Embedded Linux · C++ · Qt

CONTROL Valve / Pump GPIO

USER INTERFACE Touchscreen HMI Qt Widgets

OUTPUT Thermal Printer Serial / USB

Technology

LANGUAGEC++

FRAMEWORKQt / Qt Widgets

HARDWARERaspberry Pi

OSEmbedded Linux

PROTOCOLModbus RTU / RS485

CONTROLGPIO

DATABASESQLite

DEPLOYMENTsystemd

Key Features

Load Cells integration

Reads measurement values from industrial load cells through Modbus RTU over RS485.

Multi-stage dispensing

Uses high-flow and slowdown thresholds to control the dispensing process.

Machine control

Coordinates valves and pump outputs through the Raspberry Pi GPIO interface.

Industrial HMI

Provides a touchscreen interface designed around the operator's workflow.

Transaction management

Stores dispensing transactions and operational data for traceability.

Fault handling

Includes communication and no-flow timeout handling to prevent uncontrolled operation.

ENGINEERING NOTE

Designed around
the machine, not just the screen.

The application architecture separates the operator interface, process data and machine-control responsibilities. This makes the system easier to test, maintain and extend as additional field devices are introduced.

Industrial BatchController