Simple Irrigator controller

HW Parts used:

• NodeMCU v0.9
• Two Channel IIC I2C Logic Level Converter Bi-Directional Module 5V to 3.3V NEW
• Full Port Brass DN20 Normally Open Normally Close Valve AC/DC9V-24V BSP/NPT 3/4'' Electric Shut Off Valve For Home Water (https://www.aliexpress.com/item/AC-DC9-24V-3-4-full-port-brass-electric-ball-valve-normal-open-or-normal-closed/886318623.html)
• G1/2"/G3/4" Copper Hall Effect Liquid Water Flow Sensor Switch Flowmeter Meter J [G 3/4"]
• 5V Two 2 Channel Relay Module With optocoupler For PIC AVR DSP ARM Arduino

MQTT

Variable	Example	Meaning
MQTT_PREFIX	zavlazovac/	Left prefix appended to relay's channel, configurable in web interface.
RELAY_INDEX	1	Index of the relay, numbering starts from 1

LWT channel

Last will topic is used to detect availability, messages sent there are with retain tag enabled.

{MQTT_PREFIX}/status

Payload	Value	Retain
Available	Online	yes
Not Available	Offline	sent as LTW

State updates channel

State topic publishes current status of the relays.

{MQTT_PREFIX}/state/{RELAY_INDEX}

Payload	Value	Retain
Running	1	no
Not running	0	no

Commands channel

Command topic accepts these state request changes and accepts both string ON, OFF or interger 1, 0.

{MQTT_PREFIX}/command/{RELAY_INDEX}/power

Payload	Value
Running	1 or ON
Not running	0 or OFF

Flow meter channels

Flow meter updates are sent in format:

{MQTT_PREFIX}/{RELAY_INDEX}/{METRIC}

where {METRIC} is from:

Metric	Type	Unit
currentFlow	float	L/s
totalFlow	float	ml

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