ESP32 Upgrade Board for OpenSprinkler 3.2/3.3

UPGRADE YOUR IRRIGATION!

With this CPU board based on ESP32-C5, OpenSprinkler becomes a universal control center.

Features

• ESP32-C5-WROOM1-M8R8 Processor Module
• 16MB additional flash memory
• Wifi 6 with 2.4 + 5 GHZ
• Internal temperature sensor
• Reading out Bluetooth BLE sensors
• Dual firmware: Firmware 1 with ZigBee support, Firmware 2 with experimental Matter support
• ZigBee with two variants
  • ZigBee Hub (only via Ethernet connection, as the WiFi module is used for ZigBee, W5500 module)
  • ZigBee client for connecting to an existing ZigBee hub (WiFi possible)
• Matter firmware (experimental) supports control of all zones and reading of sensor data via the Matter interface
  • Since both ZigBee and Matter are based on IEEE 802.15.4, only one technology can be active at a time.
  • Matter function can also be disabled so that maximum WiFi / Ethernet capacity is available.
• ESP Rainmaker: Connect your OpenSprinkler natively with Alexa and Google Home

Overview of firmware changes

The OpenSprinkler firmware has been specifically expanded into a modern, networked and AI-enabled control platform since October 2025. The focus is on robust over-the-air updates, significantly expanded radio and sensor functions as well as higher system stability on ESP32-C5, ESP8266 and OSPi.

The most important extensions:

The firmware has developed from classic irrigation control to a powerful, updateable edge platform with a modern radio and automation basis.

• Online OTA with multi-stage update process including backup/restore logic, improved status feedback and extended diagnostics.
• Significant expansion of ESP32-C5 functions: IEEE 802.15.4 configuration, ZigBee client/gateway functions, BLE/ZigBee coexistence optimizations and Matter integration (experimental).
• MCP support for AI workflows: built-in firmware MCP endpoint
• Sensor stack modernized: Improvements in BLE, ZigBee, RS485/Modbus, MQTT and weather integration as well as better data preparation for automation.
• Performance and memory optimizations (including PSRAM/TLS/C5), making complex functions run more stable on resource-limited hardware.
• Ongoing compatibility and build improvements for ESP8266 and OSPi, including platform maintenance and API documentation expansion.

The OpenSprinkler UI (APP/web browser) has been significantly expanded ergonomically. The focus was on a significantly better update and device workflow, new ZigBee/Matter user interfaces, sensor visualization and broader internationalization.

The most important extensions:

The UI has been further developed into a significantly more powerful control center, with better user guidance for modern wireless features, OTA processes and sensor analytics.

• Integrated OTA update dialog for ESP32 with guided flow, progress display, reboot/restore guidance and better error management.
• Matter setup and ESP32-specific operating modes directly in the interface, including clear status and onboarding displays.
• ZigBee-UX significantly expanded: device information, vendor/cluster context, scanning/pairing flows and improved operational feedback.
• Analog sensor area expanded: log viewer, chart options, sorting, drag-and-drop order and more responsive display.
• SSL/certificate management added to the UI to make HTTPS and device trust easier to manage in everyday life.
• OTC/cloud-related connection processes simplified (including registration/linking) and several firmware-dependent UI features cleanly conditioned.
• Design and usability improvements (including theme/look & feel updates), including modernization of important dialogs and status displays.

Further details:

For comparison ESP8266 (bottom) – ESP32 (top, installed):

A notice:

• If you are upgrading from OpenSprinkler 3.2 AND a ENC28J60 If you use an adapter, you will also need it  W5500 Adapter – you can no longer use the ENC28J60.