Homie based firmware for Sonoff Basic, Sonoff S20 wifi relay or any ESP8266 based relay.

Features:

• ON/OFF relay
• Timer based relay
• Configurable default (on boot) relay state - (MQTT independent)
• Local button on/off
• Keepalive feature - device will reboot if not receive keepalive message in given time
• Reverse mode - ON command means relay off, OFF command means relay on (configurable on Homie level)
• Watchdog timer
• All Homie buildin features (OTA,configuration)

Build and upload

• Attache module via USB-RS232 adapter
• Set proper serial port number in plantformio.ini file (upload_port variable) if required
• reboot module into program mode
• Flash module:
  • execute pio run --target upload --environment sonoff for SONOFF, pio run --target upload --environment sonoffs20 for SONOFF S20 or pio run --target upload --environment generic for generic ESP8266
  • In Atom editor with PlatformIO prees F7 enter environment name (sonoff or generic) and choose PIO uload option from the list

MQTT messages

Property	Message format	Direction	Description
_HOMIE_PREFIX_/_node-id_/relay01/relayState	(ON|OFF)	Device → Controller	Current state of relay
_HOMIE_PREFIX_/_node-id_/relay01/relayState/set	(ON|OFF)	Controller → Device	Change relay state
_HOMIE_PREFIX_/_node-id_/relay01/relayTimer/set	\d+	Controller → Device	Turn on relay for specific no. of seconds
_HOMIE_PREFIX_/_node-id_/watchdog/timeOut/set	\d+	Controller → Device	Time after witch watchdog disable/enable output fo 10s
_HOMIE_PREFIX_/_node-id_/watchdog/tick/set	\d+	Controller → Device	Tick for watchdog - renew timeout of reset
_HOMIE_PREFIX_/_node-id_/keepalive/timeOut	\d+	Device → Controller	Report of keepalive timeout value (seconds), 0 - keep alive feature is not active
_HOMIE_PREFIX_/_node-id_/keepalive/timeOut/set	\d+	Controller → Device	Set Report of keepalive timeout in seconds, 0 - keep alive feature is not active
_HOMIE_PREFIX_/_node-id_/keepalive/tick/set	.*	Controller → Device	Keepalive message from controller to gateway - if device will not receive during keepAliveTimeOut time slot, it will reboot, keepalive is not active when keepAliveTimeOut is equal 0
_HOMIE_PREFIX_/_node-id_/$online	(true|false)	Device → Controller	/true when the device is online, false when the device is offline (through LWT)