⚠️ This project builds on work originally shared by milwhite in this Home Assistant community post.

ha-esp32-variable-speed-drive-esphome

Control a variable speed drive (such as the iSAVER+ 1100) using an ESP32 and ESPHome, fully integrated with Home Assistant. This setup lets you read actual RPM, set speed, and control power via Modbus over RS485.

⚠️ Disclaimer

This configuration has only been tested on the following device:

🔗 InverSilence iSAVER+ 1100 – Folkpool

I take no responsibility for how this setup might impact your device. Use it at your own risk. Your specific model may not be compatible, and incorrect usage might damage your equipment.

If you do manage to get it working with a different variable speed drive, I’d love to hear about it — your feedback could help others in the community!

🛠️ Hardware

🧾 Bill of Materials (BOM)

Item	Description	Example / Link
ESP32 Dev Board	Main controller running ESPHome	HiLetgo ESP32 Dev Board
RS485 to UART Module	For Modbus communication over UART	MAX485 RS485 Module
Variable Speed Drive	The pump controller we're interfacing with	iSAVER+ 1100 (or similar)
Dupont cables / breadboard wires	For connecting components	Any female-to-female and male-to-male jumper wires
Power supply	5V USB power for ESP32	e.g. phone charger, USB power brick

📡 ESPHome Configuration

The ESPHome YAML file is in esphome/isaver.yaml.

To use it:

1. Replace WiFi credentials in your secrets.yaml
2. Flash your ESP32
3. Add the device to Home Assistant
4. Optionally adjust the Modbus logic to fit your specific drive

💡 Dashboard Preview

Here’s what the finished control panel looks like in Home Assistant:

🏡 Home Assistant Integration

You can use the exposed number, sensor, switch, and button entities directly in dashboards or automations.

Lovelace Files

File	Description
gauge.yaml	RPM gauge
preset_buttons.yaml	ECO / NORMAL / MAX speed buttons
status_panel.yaml	On/off switch, actual RPM, Modbus info
max_rpm_button.yaml	Triggers 2-hour Max RPM script

Lovelace files are in examples/lovelace/

🧪 Bonus: Temporary Max Speed Script

To enable the “Max RPM for 2h!” button, create this in your scripts.yaml or load it from examples/scripts/:

alias: Pump Max Then Restore
mode: single
sequence:
  - variables:
      previous: "{{ states('number.pump_rpm_regulator_pool_pump_rpm') | int }}"
  - service: number.set_value
    target:
      entity_id: number.pump_rpm_regulator_pool_pump_rpm
    data:
      value: 2900
  - delay: "02:00:00"
  - service: number.set_value
    target:
      entity_id: number.pump_rpm_regulator_pool_pump_rpm
    data:
      value: "{{ previous }}"

📁 Folder Structure

ha-esp32-variable-speed-drive-esphome/
├── README.md
├── LICENSE
├── .gitignore
├── esphome/
│   └── isaver.yaml
├── docs/
│   └── 
├── examples/
│   ├── lovelace/
│   │   ├── gauge.yaml
│   │   ├── preset_buttons.yaml
│   │   ├── status_panel.yaml
│   │   └── max_rpm_button.yaml
│   └── scripts/
│       └── pump_max_then_restore.yaml
└── images/
    └── pump.png

🔌 Wiring Diagram (ASCII)

⚠️ Important Wiring Note

GPIO5 (IO5) on the ESP32 must be connected to both the RE and DE pins on the RS485 module.
This ensures proper direction control for Modbus communication.

                          RS485
   ESP32                  Module B              Variable Speed Drive
+---------+           +-----------+           +----------------------+
|         |           |          A|   ---->   | A                    |
|      17 +---------->+ DI        |           |                      |
|         |           |          B|   ---->   | B                    |
|      16 +<----------+ RO        |           +----------------------+
|         |           |           |
|       5 +---------->+  RE/DE    |
|         |           |   GND     |
+---------+           +-----------+
                           |
                           |
                          GND

🧠 How It Works

This ESPHome config sends and receives Modbus messages over UART using a custom lambda. It sets the desired RPM via a Modbus write and reads the current RPM in a loop.

A GPIO pin is used to toggle the RS485 write-enable line before/after communication to avoid collisions.

💧 Smarter Pool Pump Scheduling

GoNow when you have variable speed pump you might want to save energy and keep things quiet? We've put together a simple example that helps you figure out a daily schedule based on your pool size and pump settings.

Check it out here:
👉 docs/example_schedule.md

It shows:

• How to calculate how much water your pump needs to move
• What different RPMs mean for flow and power use
• A sample schedule that keeps things clean without wasting energy