RelayBoardX3

Relay board X3

Work in progress / still a prototype...

A DYI 3x relay board based on ESP32c3. This is a multi purpose board used for:

• Garage doors - controlling dual garage doors and control use of external switches
• Ventilator / 1-phase small motor 1-2-3 speed control.

This board is tested with ESPhome and ESPEasy firmware (build instructions below), and is easily used with home automation systems that support MQTT auto discovery, the native Home Assistant API, and the many controllers that ESPEasy supports

Introduction

Some of the main features and benefits

• 3x galvanic isolated relays
• Car precense sensors
  • Ultrasound sensor option
• I2C support
  • An I2C pin header with power supply is available to use with I2C sensors
  • ... or you can use the same GPIO pins for any other purpose of your choise
• WiFi based
  • This is almost a must have for most home automation systems
  • OTA support
  • Configuration backup, restore and bulk updates.
• Firmware of your choise
  • ESPEasy with Domoticz over http. Device creation uses virtual sensors
  • ESPEasy with Domotics and Home Assistant via MQTT. Device creation uses a MQTT configuration text file.
  • ESPHome to Home Assistant via MQTT and auto discovery
  • ESPHome to Domoticz via MQTT and auto discovery
  • ... and as the hardware supports using both Arduino and ESP-IF development kits, almost any other firmware can be created.
• Seed Studio XIAO ESP32C3
  • This device is shielded and comes with an external IPX antenna connector
  • FCC and CE regulations approved

Indicators

Each of the four valve outputs has a LED indicator at the back of the PCB

• LED D11 will indicate low level input from the flow meter
• LED D1
  • no change indicates out of power, device death/freeze or other
  • a duty cycle 1:1 will indicate a reset is ongoing

Implementation and design

The schematic diagram is available here. The KiCad EDA project is in the same folder

GPIO pin usage

Hardware - getting started

This project uses my KiCad-lib-ESP32 repository as a git submodule. To check this out, use the following:

git clone --recurse-submodules https://github.com/hansrune/RelayBoardX4.git 

Materials used

This project uses the Seed Studio XIAO ESP32C3 RISC-V module. This tiny device has proven to be more reliable than most ESP8266 modules used in earlier versions. This module also comes with an IPX connector for connecting an external antenna, and is delivered with a simple external antenna for good range. This device is also EMI shielded and certified.

Any available 12V DC power supply delivering 500mA or more should do for the control board. You will need to add the total power draw for the relays

There are many options and possible pinouts for DC-DC converters for the 12V to 5V conversion. A linear regulator (L7805) will need a heatsink, so a DC-DC converter is recommended.

The MOSFETs need a low Vgs trigger voltage, i.e. well under 3V on full load. I have used Si2302/N025P for the N-channel, SOT-23 package.

Resistors are 0805 size. Screw terminals are 3.5mm, which is a tight fit when ferrules are being used.

For more information, use this KiCad BOM

Hardware assembly

Soldering a prototype by hand is possible if you have a steady hand and a small solder iron tip. A microscope is recommended to inspect the solder joints properly.

Recommend to do the SMD parts first, then other components.

Hardware tests

You should test at least the following before adding the ESP32 module:

• Attach a battery and check that the valve can be operated both NO and NC
• Add power and check that 5V conversion is OK
• Apply 5V to GPIO 5, 6, and 10 in turn to check that the output works with the relay LED indicators

Firmwares

ESPHome

ESPHome firmware can be set up from this ESPHome configuration repository using the test_relayx3_garage.yaml or test_relayx3_motor.yaml file as a template

Follow the README for instructions on what you will likely want to change.

By default, MQTT auto discovery is being used. This should work out of the box with Home Assistant, Domoticz and other that support Home Assistant MQTT Auto Discovery

Garage doors control

In Home Assistant, the garage door controls can look like this:

... and the closed state end stop sensors:

Motor control

In Home Assistant, the device has this simple selector:

ESPEasy

ESPEasy can be used with a number of different controllers / home automation systms. A custom firmware build description is available here

ESPEasy requires many settings. For configuration settings and rule files, you can upload the below sets of files. Please make sure to change name, unit number, controller IP addresses, NTP, syslog host and latitude/longitude. This configuration uses both a MQTT controller and a Domoticz controller. Change to what you need.

• For the garage control, use the files under this page
• For the motor/ventilator control, use the files under [this page](./ESPEasy/motor/config.dat

Wiring

Dual garage door wiring

This dual garage door setup uses a pulse driven elevator, and has end stop switches for the closed position. There is no end stops for the open position, meaning that the open state simply reflects not closed.

A RX-Multi receiver is used in parallel with the relay board. This is operated by remote control units from a car.

We have outdoor push buttons to operate the garage doors. These are disabled via relay #1 when our home alarm state is away or night. The power on state is that these buttons are enabled.

Motor control wiring

This setup is a simple 1-2-3 speed motor control for a ventilator. Can work in parallel with a 1-2-3 switch, where you will get the highest speed selected via contoller or switch.

Licensing

This project is licensed under the GNU General Public License v3.0 for the software, CERN-OHL-W for the hardware, and CC BY-SA for the documentation and ideas.