There are not many dedicated sprinkler controllers on the internet that can be integrated with Home Assistant. Moreover, most available electromagnetic valves use AC, which creates the problem of needing an additional power supply to get them working. Nowadays, you can buy DC coils (for example, Hunter makes some), but they are much more expensive.
Solution used so far.
Previously, I used a modified LILYGO T-Relay with an external WiFi antenna. It worked reliably, but as mentioned, it required a DC power supply for the T-Relay and AC for the coils. After a few years of reliable operation, I added another watering section to my garden. However, since I used a T-Relay with 4 relays and none were free anymore, I needed to find a new solution.
New possible solutions:
Additional Relay:
The ESP32 board has enough GPIOs to control many more relays, but due to the external DC PSU, I ran out of space in the hermetic box. Buying a new one was not an option because the old one was already too big.
Design own PCB:
Years ago, I designed my own PCBs, but now I’m older, lazier, and don’t have as much time. Like the previous proposal, this idea was also rejected.
Find an Out-of-the-Box Solution:
Solutions from big companies are usually very expensive and often cannot be integrated with Home Assistant.
After days of searching online, I was unable to find any suitable solution for controlling 24 ACV valves over ZigBee. Moreover, WiFi-based solutions are also limited to Tuya Cloud.
Summary.
It is very hard to find a solution that fits the needs of cloud-independent home automation.
Experiment.
During research for another project, I found that it’s possible to bypass Tuya Cloud using different tools, so I decided to buy a controller like the one shown below.
When it arrived, I decided to disassemble it. The front acrylic panel is glued with thin double-sided tape, so to remove it, you need to use a thin knife and carefully pry off the panel.
Inside, there is a CBU unit. After some research, I found that it can be flashed with ESPHome, so I decided to try it. I also found a place for a U.FL connector, so I used an external WiFi antenna because the device is located in a metal enclosure.
To flash the CBU unit, you have to solder cables or use a 3D-printed adapter called the Tuya CBU Flashing Jig
These are the results of all those operations
ESPHome
Now it was time for some reverse engineering and coding. I spent a few hours testing and tweaking the code, and here is the resulting configuration, which supports the controller’s LED indicators and touch buttons.
esphome:
name: "smart-sprinkler"
friendly_name: "smart-sprinkler"
bk72xx:
board: cbu
# Enable logging
logger:
# Enable Home Assistant API
api:
encryption:
key: ""
ota:
- platform: esphome
password: ""
wifi:
ssid: !wifi_iot_ssid
password: !wifi_iot_password
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Smart-sprinkler Fallback Hotspot"
password: ""
fast_connect: True
captive_portal:
# Configure shift registers
sn74hc595:
- id: 'sn74hc595_hub'
data_pin: GPIO9
clock_pin: GPIO15
latch_pin: GPIO17
sr_count: 2
- id: 'sn74hc595_relay_hub'
data_pin: GPIO16
clock_pin: GPIO22
latch_pin: GPIO20
sr_count: 2
output:
- platform: gpio
id: status_led_1
pin:
sn74hc595: sn74hc595_hub
number: 0
inverted: true
- platform: template
type: binary
id: status_led_1_temp
write_action:
- while:
condition:
lambda: return (state > 0);
then:
- output.turn_on: status_led_1
- delay: 500ms
- output.turn_off: status_led_1
- delay: 500ms
- output.turn_off: status_led_1
- platform: gpio
id: status_led_2
pin:
sn74hc595: sn74hc595_hub
number: 1
inverted: true
- platform: template
type: binary
id: status_led_2_temp
write_action:
- while:
condition:
lambda: return (state > 0);
then:
- output.turn_on: status_led_2
- delay: 500ms
- output.turn_off: status_led_2
- delay: 500ms
- output.turn_off: status_led_2
- platform: gpio
id: status_led_3
pin:
sn74hc595: sn74hc595_hub
number: 2
inverted: true
- platform: template
type: binary
id: status_led_3_temp
write_action:
- while:
condition:
lambda: return (state > 0);
then:
- output.turn_on: status_led_3
- delay: 500ms
- output.turn_off: status_led_3
- delay: 500ms
- output.turn_off: status_led_3
- platform: gpio
id: status_led_4
pin:
sn74hc595: sn74hc595_hub
number: 3
inverted: true
- platform: template
type: binary
id: status_led_4_temp
write_action:
- while:
condition:
lambda: return (state > 0);
then:
- output.turn_on: status_led_4
- delay: 500ms
- output.turn_off: status_led_4
- delay: 500ms
- output.turn_off: status_led_4
- platform: gpio
id: status_led_5
pin:
sn74hc595: sn74hc595_hub
number: 4
inverted: true
- platform: template
type: binary
id: status_led_5_temp
write_action:
- while:
condition:
lambda: return (state > 0);
then:
- output.turn_on: status_led_5
- delay: 500ms
- output.turn_off: status_led_5
- delay: 500ms
- output.turn_off: status_led_5
- platform: gpio
id: status_led_6
pin:
sn74hc595: sn74hc595_hub
number: 5
inverted: true
- platform: template
type: binary
id: status_led_6_temp
write_action:
- while:
condition:
lambda: return (state > 0);
then:
- output.turn_on: status_led_6
- delay: 500ms
- output.turn_off: status_led_6
- delay: 500ms
- output.turn_off: status_led_6
- platform: gpio
id: status_led_7
pin:
sn74hc595: sn74hc595_hub
number: 6
inverted: true
- platform: template
type: binary
id: status_led_7_temp
write_action:
- while:
condition:
lambda: return (state > 0);
then:
- output.turn_on: status_led_7
- delay: 500ms
- output.turn_off: status_led_7
- delay: 500ms
- output.turn_off: status_led_7
- platform: gpio
id: status_led_8
pin:
sn74hc595: sn74hc595_hub
number: 7
inverted: true
- platform: template
type: binary
id: status_led_8_temp
write_action:
- while:
condition:
lambda: return (state > 0);
then:
- output.turn_on: status_led_8
- delay: 500ms
- output.turn_off: status_led_8
- delay: 500ms
- output.turn_off: status_led_8
- platform: gpio
pin: 28
id: led_wifi
inverted: true
interval:
- interval: 1s
then:
if:
condition:
wifi.connected:
then:
- output.turn_on: led_wifi
else:
- output.turn_off: led_wifi
# Interval for closing cycle of choosing valves
- interval: 120s
then:
if:
condition:
lambda: !lambda |-
if (id(valve_id)){
return true;
}
return false;
then:
lambda: !lambda |-
id(recover_status_led).execute();
id(valve_id) = 0;
# Valves configuratin
switch:
- platform: gpio
name: valve_1
id: valve_1
pin:
sn74hc595: sn74hc595_relay_hub
number: 0
on_turn_on:
- output.turn_on: status_led_1
on_turn_off:
- output.turn_off: status_led_1
- platform: gpio
name: valve_2
id: valve_2
pin:
sn74hc595: sn74hc595_relay_hub
number: 1
on_turn_on:
- output.turn_on: status_led_2
on_turn_off:
- output.turn_off: status_led_2
- platform: gpio
name: valve_3
id: valve_3
pin:
sn74hc595: sn74hc595_relay_hub
number: 2
on_turn_on:
- output.turn_on: status_led_3
on_turn_off:
- output.turn_off: status_led_3
- platform: gpio
name: valve_4
id: valve_4
pin:
sn74hc595: sn74hc595_relay_hub
number: 3
on_turn_on:
- output.turn_on: status_led_4
on_turn_off:
- output.turn_off: status_led_4
- platform: gpio
name: valve_5
id: valve_5
pin:
sn74hc595: sn74hc595_relay_hub
number: 4
on_turn_on:
- output.turn_on: status_led_5
on_turn_off:
- output.turn_off: status_led_5
- platform: gpio
name: valve_6
id: valve_6
pin:
sn74hc595: sn74hc595_relay_hub
number: 5
on_turn_on:
- output.turn_on: status_led_6
on_turn_off:
- output.turn_off: status_led_6
- platform: gpio
name: valve_7
id: valve_7
pin:
sn74hc595: sn74hc595_relay_hub
number: 6
on_turn_on:
- output.turn_on: status_led_7
on_turn_off:
- output.turn_off: status_led_7
- platform: gpio
name: valve_8
id: valve_8
pin:
sn74hc595: sn74hc595_relay_hub
number: 7
on_turn_on:
- output.turn_on: status_led_8
on_turn_off:
- output.turn_off: status_led_8
- platform: gpio
name: motor
id: motor
pin:
number: 24
globals:
# Variable used for switch case to choose valve using buttons
- id: valve_id
type: int
restore_value: no
initial_value: '0'
#Physical buttons configuration with actions
binary_sensor:
- platform: gpio
id: back
pin:
number: 7
mode:
input: true
pullup: true
on_press:
then:
lambda: !lambda |-
id(recover_status_led).execute();
id(valve_id) = (id(valve_id) - 1);
id(blink_status_led).execute();
- platform: gpio
id: forward
pin:
number: 6
mode:
input: true
pullup: true
on_press:
then:
lambda: !lambda |-
id(recover_status_led).execute();
id(valve_id) = (id(valve_id) + 1);
id(blink_status_led).execute();
- platform: gpio
id: play
pin:
number: 8
mode:
input: true
pullup: true
on_press:
then:
script.execute: toogle_valve
- platform: gpio
id: config
pin:
number: 26
mode:
input: true
pullup: true
on_press:
then:
lambda: !lambda |-
id(recover_status_led).execute();
id(valve_id) = 0;
script:
# Restore previous status of led
- id: recover_status_led
then:
lambda: !lambda |-
switch (id(valve_id)){
case 1:
id(status_led_1_temp).turn_off();
if (id(valve_1).state){
id(status_led_1).turn_on();
}
break;
case 2:
id(status_led_2_temp).turn_off();
if (id(valve_2).state){
id(status_led_2).turn_on();
}
break;
case 3:
id(status_led_3_temp).turn_off();
if (id(valve_3).state){
id(status_led_3).turn_on();
}
break;
case 4:
id(status_led_4_temp).turn_off();
if (id(valve_4).state){
id(status_led_4).turn_on();
}
break;
case 5:
id(status_led_5_temp).turn_off();
if (id(valve_5).state){
id(status_led_5).turn_on();
}
break;
case 6:
id(status_led_6_temp).turn_off();
if (id(valve_6).state){
id(status_led_6).turn_on();
}
break;
case 7:
id(status_led_7_temp).turn_off();
if (id(valve_7).state){
id(status_led_7).turn_on();
}
break;
case 8:
id(status_led_8_temp).turn_off();
if (id(valve_8).state){
id(status_led_8).turn_on();
}
break;
}
# Blink single status led choosen using buttons
- id: blink_status_led
then:
lambda: !lambda |-
switch (id(valve_id)){
case 1:
id(status_led_1_temp).turn_on();
break;
case 2:
id(status_led_2_temp).turn_on();
break;
case 3:
id(status_led_3_temp).turn_on();
break;
case 4:
id(status_led_4_temp).turn_on();
break;
case 5:
id(status_led_5_temp).turn_on();
break;
case 6:
id(status_led_6_temp).turn_on();
break;
case 7:
id(status_led_7_temp).turn_on();
break;
case 8:
id(status_led_8_temp).turn_on();
break;
default:
id(valve_id) = 0;
break;
}
- id: toogle_valve
then:
lambda: !lambda |-
switch (id(valve_id)){
case 1:
id(valve_1).toggle();
break;
case 2:
id(valve_2).toggle();
break;
case 3:
id(valve_3).toggle();
break;
case 4:
id(valve_4).toggle();
break;
case 5:
id(valve_5).toggle();
break;
case 6:
id(valve_6).toggle();
break;
case 7:
id(valve_7).toggle();
break;
case 8:
id(valve_8).toggle();
break;
}
