N.E.R.D. Remote Valve Controller

ESP32-S3 + LVGL + TMC2209 motorized remote valve controller designed for marine and industrial fluid automation systems.

The N.E.R.D. Remote Valve Controller is a compact touchscreen-based stepper valve actuator platform developed as part of the N.E.R.D. (Nautical Embedded Resource Director) ecosystem.

This project combines:

• ESP32-S3
• LVGL touchscreen UI
• TMC2209 UART stepper control
• Persistent valve position memory
• Automatic software recalibration
• Configurable software travel limits

to create a reliable and repeatable remote-controlled proportional valve actuator suitable for:

• Marine automation
• Watermakers
• Fluid systems
• Pressure regulation
• Experimental process control

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Current Hardware Platform

Main Controller

• Waveshare ESP32-S3 Touch LCD 1.9"
• 170x320 IPS touchscreen
• USB-C powered during development

Stepper Driver

• BIGTREETECH TMC2209 V1.2
• UART mode enabled
• STEP/DIR control
• Software-configurable current

Stepper Motor

• Standard NEMA17 stepper motor

Valve

Current prototype tested with:

• Tognella FT 2251/2-01 AISI316 double-acting flow control valve

Official product page:

https://www.tognella.it/en/flow-rate-control-valves/line-double-acting-flow-control-valves-ft-2251-2-01

The valve provides extremely smooth and progressive regulation and proved well suited for stepper-based remote actuation.

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Features

Touchscreen UI

The controller includes a fully standalone LVGL interface with:

• OPEN / CLOSE controls
• LOW / MED / HIGH speed selection
• Valve turns display
• Live status indication
• OPEN ZERO / CLOSED ZERO calibration buttons

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Persistent Position Memory

Valve position is automatically saved to ESP32 flash memory whenever movement stops.

After reboot, the controller restores:

• Valve position
• Calibration reference
• Travel logic

This allows recovery even after power loss while the valve is in an intermediate position.

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Automatic Poor-Man Recalibration

The controller implements a practical self-recalibration system:

• Valve travel configured slightly larger than real mechanical travel
• When the actuator reaches a software end-stop, the controller automatically redefines its reference position

Example:

• Reaching full OPEN automatically performs OPEN ZERO
• Reaching full CLOSED automatically performs CLOSED ZERO

This compensates small accumulated step errors without requiring:

• Encoders
• Hall sensors
• Limit switches

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Software Travel Limits

Current prototype:

VALVE_TRAVEL_TURNS = 6.8f;

The software prevents overtravel in both directions depending on the selected reference side.

Example:

If OPEN ZERO is set:

• OPEN limit = 0
• CLOSED limit = +6.8 turns

If CLOSED ZERO is set:

• CLOSED limit = 0
• OPEN limit = -6.8 turns

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TMC2209 UART Notes

UART communication is fully functional and used for:

• Driver configuration
• Current control
• Diagnostics
• Runtime tuning

Important Discovery

12V motor supply must be present BEFORE ESP32/TMC UART initialization.

Without motor supply present before UART initialization, the TMC2209 may fail communication.

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StallGuard Notes

TMC2209 StallGuard experiments were performed extensively during development.

Results

• UART communication works correctly
• SG_RESULT values are readable
• StallGuard proved unreliable for this specific valve/mechanical configuration

For this reason, the current controller architecture relies on:

• Software travel limits
• Persistent position memory
• Automatic recalibration

instead of sensorless StallGuard homing.

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GPIO / Wiring Overview

ESP32-S3 ↔ TMC2209

Function	GPIO
STEP	GPIO5
DIR	GPIO6
ENABLE	GPIO7
UART TX	GPIO4
UART RX	GPIO18

UART Configuration

• GPIO4 connected through 1k resistor
• GPIO18 connected directly
• Both connected to PDN_UART

TMC2209 Power

TMC2209 Pin	Connection
VS	12V motor supply
VIO	3.3V ESP32
GND	Common ground

All grounds must be shared.

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Current Status

Current DEV03 firmware status:

• Stable
• Fully operational
• Repeatable positioning
• Persistent storage working
• Automatic recalibration working
• Touchscreen UI stable

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Intended Applications

• Marine automation
• Watermaker pressure regulation
• Remote fluid control
• Experimental hydraulic systems
• Process automation
• DIY industrial control
• ESP32/TMC2209 research projects

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License

This project is released for:

• Educational use
• Personal use
• Non-commercial experimentation

Commercial use, resale or commercial integration is not permitted without explicit permission from the author.

© CobrAm GmbH

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N.E.R.D. Ecosystem

This project is part of the broader:

N.E.R.D. — Nautical Embedded Resource Director

marine automation ecosystem currently under development.