About

Arduino program to handle relays and control them using switches. Single pair of relay and switch are configured in single line. Buttons has debouncing and support for mono- and bi-stable switches. There is support for multiple switches for single relay.

I left configuration variable myRelayButtons[] which is used at my house, so before use you HAVE TO change it.

Configuration

Main config

RelayButton myRelayButtons[] = {
    {sensor ID, relay pin, button pin, relay options, button type, relay description}
};

Params description:

• sensor ID - sensor ID reported on MySensor Gateway (ie. Domoticz/Home Assistant), must be unique (can be -1 when it is not reported MySensor Gateway)
• relay pin - pin connected to the relay. Expander is supported (see details inseparate section)
• button pin - pin connected to the button. There can be multiple buttons to the same relay. "<0" for virtual buttons (only available in MySensor Gateway, ie. Domoticz/Home Assistant). There is no support for Expander because of de-bouncing.
• relay options - combined with '|' operator:
  • trigger level - RELAY_TRIGGER_LOW or RELAY_TRIGGER_HIGH
  • startup state - optional, RELAY_STARTUP_ON or RELAY_STARTUP_OFF
• button type:
  • MONO_STABLE - GND connected to the button pin
  • BI_STABLE - state change from LOW to HIGH and HIGH to LOW, used with mechanical and touch buttons
  • DING_DONG - doorbell button, relay is triggered only when button is pushed (experimental, not tested)
• relay description - reported on MySensor Gateway, can help identify device on initial configuration in Home Automation App (ie. Domoticz/Home Assistant), can be empty ("")

In my case, I have a documentation of whole electricity of my house in Google Calc, and I have a formula to generate this configuration.

Debugging

#define MY_DEBUG

Just comment this on production.

Sample configurations

Simple mono-stable switch and relay pair

Relay is connected to pin 12, button is connected to pin 11, relay is triggered to ON using LOW state, button is mono-stable

RelayButton myRelayButtons[] = {
    {1, 12, 11, LOW, MONO_STABLE, ""}
};

Simple bi-stable switch and relay pair

Relay is connected to pin 12, button is connected to pin 11, relay is triggered to ON using HIGH state, button is bi-stable

RelayButton myRelayButtons[] = {
    {1, 12, 11, HIGH, BI_STABLE, ""}
};

Simple two mono-stable switch for one relay

Relay is connected to pin 12, buttons are connected to pins 11 and 10, relay is triggered to ON using HIGH state, buttons are mono-stable

RelayButton myRelayButtons[] = {
    {1, 12, 11, HIGH, MONO_STABLE, ""}
    {2, 12, 10, HIGH, MONO_STABLE, ""}
};

Expander

Only one expander library at a time is supported.

PCF8574

To use expander PCF8574 you have to install library (https://github.com/skywodd/pcf8574_arduino_library) Basic information about expander and library you can find here - https://youtu.be/JNmVREucfyc (PL, library in description)

And uncomment expander library:

#include "PCF8574.h"

MCP23017

https://github.com/adafruit/Adafruit-MCP23017-Arduino-Library

Uncomment expander library:

#include "Adafruit_MCP23017.h"

Configuration

Configure all expanders id: I.e. only one PCF8574 expander with id = 0x20:

uint8_t expanderAddresses[] = {0x20};

I.e. only one MCP23017 expander with id = 0:

uint8_t expanderAddresses[] = {0};

From now you can use expander pins in configuration myRelayButtons[]. To recognize expander pin, numbers start from 0x0100 and have special meaning:

• first byte - expander number (starts from 1)
• second byte - pin number In example - "0x0100" means pin 0 on first expander

To simplify using expanders, there is "E(a,b)" macro:

• a - expander number (starts from 0)
• b - pin on expander [0-f]

E(0,0) - first pin on first expander