VIN terminal.| Terminal | GPIO | Function | Signal | Notes |
|---|---|---|---|---|
| VIN / GND | – | Power Supply | 12–24V DC | Polarity protected. Use a clean industrial PSU. |
| CH1 / COM1 / NC1 | 27 | Zone 1 Valve Relay | 10A SPDT | Valve solenoid: NO–COM for normally-closed valves. |
| CH2 / COM2 / NC2 | 14 | Zone 2 Valve Relay | 10A SPDT | As above. |
| CH3 / COM3 / NC3 | 12 | Zone 3 Valve Relay | 10A SPDT | As above. |
| CH4 / COM4 / NC4 | 13 | Zone 4 Valve Relay | 10A SPDT | As above. |
| IN1 | 19 | Configurable Input 1 | NPN opto | Assign function in Settings. |
| IN2 | 18 | Configurable Input 2 | NPN opto | Assign function in Settings. |
| IN3 | 5 | Configurable Input 3 | NPN opto | Assign function in Settings. |
| IN4 | 17 | Configurable Input 4 | NPN opto | Assign function in Settings. |
| VI1 | 36 | Analog Input 1 (0–10V) | 0–10V | Soil moisture, pressure, etc. |
| VI2 | 39 | Analog Input 2 (0–10V) | 0–10V | Second process sensor. |
| II1 | 34 | Analog Input 3 (4–20mA) | 4–20mA | Flow transmitter, pressure transmitter. |
| II2 | 35 | Analog Input 4 (4–20mA) | 4–20mA | Spare sensor input. |
| VO1/IO1 | 25 | Analog Output 1 | 0–10V or 4–20mA | Select via SW1 DIP switch. Drive VFD or prop valve. |
| A+ / B– | 1/3/22 | RS485 Bus | Differential | Modbus RTU (optional). |
Each of IN1–IN4 can be independently assigned in Settings.
| Function | Wiring | Behaviour |
|---|---|---|
| Disabled | Leave open | Input completely ignored. |
| Flow Meter | Hall-effect pulse sensor → IN, +5V, GND | ISR pulse counter. Divides by K-factor (pulses/litre) to track volume and flow rate. |
| Float / Stop Switch | Float switch → IN, GND | When active: immediately stops all running zones. |
| Rain Sensor | Rain sensor NC output → IN, GND | When active: inhibits all scheduled runs. Manual control still works. |
| Pressure Switch | Low-pressure NC switch → IN, GND | When active: stops all zones and latches a pressure fault. |
| Manual Button | Momentary NO button → IN, GND | Each press toggles AUTO ↔ MANUAL mode. |
| Fault Input | External fault relay → IN, GND | Latches fault and stops all zones while active. |
| Master Flow | Master meter pulse → IN, GND | Counts total system flow across all zones. |
Each zone supports up to 8 schedules. Every schedule has a start time, duration (seconds), and a weekday bitmask.
| Day | Bit value | Day | Bit value |
|---|---|---|---|
| Sunday | 1 | Thursday | 16 |
| Monday | 2 | Friday | 32 |
| Tuesday | 4 | Saturday | 64 |
| Wednesday | 8 | Every day | 127 |
Examples: Mon–Fri = 62 | Weekends = 65 | Mon/Wed/Fri = 42
Schedules skip automatically when: rain sensor active, system fault latched, or controller in MANUAL mode.
Access from any browser: http://kpjirrigation.local or the IP in the header. AP is always available at http://192.168.4.1.
| Topic | Dir | Payload |
|---|---|---|
kpj/irrigation/status | Publish (30s) | JSON — all live values |
kpj/irrigation/cmd/zone/N | Subscribe | {"action":"on","duration":300} |
kpj/irrigation/cmd/all | Subscribe | off |
kpj/irrigation/cmd/mode | Subscribe | auto / manual / reset |
| Pin | Dir | Value |
|---|---|---|
| V0 | W | Mode: 0=AUTO, 1=MANUAL |
| V1–V4 | W | Zone 1–4 on (1) / off (0) |
| V5 | W | All Stop (send 1) |
| V10–V13 | R | Zone 1–4 active state |
| V20–V23 | R | Analog inputs 1–4 (scaled) |
In Arduino IDE go to Tools > Port and select the kpj-irrigation network port. OTA password: kpjota2024
| Symptom | Likely Cause | Fix |
|---|---|---|
| Zone runs but valve doesn't open | Valve wiring or wrong terminal | Check CH/COM/NC. Most solenoids: NO–COM. Verify 24VAC supply to valve. |
| Rain inhibit stuck ON | Sensor still wet or wiring fault | Check IN wiring. If no sensor is fitted, set that input to Disabled in Settings. |
| Schedule not running | No NTP sync or wrong timezone | Ensure WiFi connected. Check GMT offset. Verify weekday bitmask includes today. |
| Flow reads 0 with meter connected | Wrong input function or K-factor | Assign input as Flow Meter in Settings. Check K-factor value. |
| Analog reads wrong value | Wrong scale or wrong terminal | VI1/VI2 = 0–10V, II1/II2 = 4–20mA. Adjust min/max in Settings. |
| WiFi not reconnecting | Credentials not saved | Connect to KPJ-Irrigation AP → go to http://192.168.4.1/wifi |
| Dashboard shows -- | Browser cannot reach /status | Check WiFi, try IP directly, or use AP at 192.168.4.1 |
| Fault latched, won't clear | Fault input still active | Fix the root cause (pressure, float, external fault) then tap RESET. |
ilima irrigate V1.2 | KPJ-Control Board