A custom PCB for an ESP32-C3 based plant watering controller that features two channels to drive 12V water pumps and one input to check for low water level. If using esphome as firmware it can be easily integrated into Home Assistant.
If you'd like to solder the PCB yourself, the smallest component to be soldered is 0603. The list of components and their placement is available as interactive BOM.
If you only need one channel (for a single pump), you can leave R5, R6, R11 D7, D9, Q2 and J3 unpopulated.
Documentation is probably far from complete. If you are missing a piece of the puzzle, feel free to open an issue or improve the documentation using a PR.
| References | Value | LCSC part # |
|---|---|---|
| C1 | 10nF | C57112 |
| C2 | 10uF | C15849 |
| C3 | 10uF | C89632 |
| C4 | 10uF | C336204 |
| C5 | 150uF | C242120 |
| C6, C8 | 100nF | C1591 |
| C7 | 1uF | C15849 |
| C9 | 10uF | C194427 |
| R2, R7, R8, R9 | 10k | C25804 |
| R3, R6 | 1k | C21190 |
| R4, R5, R13 | 47k | C25819 |
| R10, R11 | 100 | C22775 |
| R12, R14 | 27 | C863706 |
| R15, R16 | 5.1k | C23186 |
| R1 | 5.9k | C23071 |
| L1 | 68uH | C694542 |
| D1 | PMEG6010CEH,115 | C110797 |
| D2 | SMAJ15CA | C110044 |
| D3 | SS52 | C727051 |
| D4 | B5819W SL | C8598 |
| D5 | CUS10S30,H3F | C146335 |
| D6, D7 | LED | C434419 |
| D8, D9 | SS56 | C2904059 |
| D10 | LC03CI | C384865 |
| U1 | TPS5430DDA | C9864 |
| U2 | AMS1117-3.3 | C347222 |
| U3 | SRV05-4 | C85364 |
| U4 | ESP32-C3-WROOM-02 | C2934560 |
| F1 | BSMD1812-200-24V | C206993 |
| SW1, SW2 | XUNPU TS-1089S-02526 | C455282 |
| Q1, Q2 | IRF7401 | C5346818 |
| J1, J2, J3 | DB128L-5.08-2P-GN-P | C430600 |
| J4 | USB-C Connector | C165948 |
| J5 | DB125-2.54-2P-GN-S | C918120 |
I am sourcing my components from LCSC. If you also do, the LCSC part # may be helpful.
For a full-fledged plant watering solution you'll need some additional components/parts. Links go to AliExpress, but you can of course source the components from other sources if you prefer a different suppliers.
- Submersible 12V water pump
- Water level sensor
- Water filter (8mm)
- Sprinklers
- 8mm to 4mm connector
- 8mm hose
- 4mm hose
- Water reservoir, e.g., IKEA HÅLLBAR (35 l)
The firmware I am running on the controller is based on esphome. I am using the following snippet (for a single channel and a moisture sensor named sensor.plant_herbs_balcony_soil_moisture), which you'll probably want to customize to integrate with your Home Assistant instance and WiFi.
globals:
- id: last_run
type: time_t
restore_value: yes
initial_value: '0'
esphome:
name: plant-watering
name_add_mac_suffix: true
friendly_name: ESP32-C3 Plant Watering Controller
platformio_options:
board_build.flash_mode: dio
board_build.f_flash: 40000000L
board_build.flash_size: 4MB
# run with 80 MHz
board_build.f_cpu: 80000000L
esp32:
board: esp32-c3-devkitm-1
framework:
type: esp-idf
sdkconfig_options:
CONFIG_COMPILER_OPTIMIZATION_SIZE: y
variant: esp32c3
mqtt:
broker: [...]
username: [...]
password: [...]
on_message:
- topic: esphome/plant_watering/pump1
payload: 'ON'
then:
- if:
condition:
binary_sensor.is_on: water_level
then:
- globals.set:
id: last_run
value: !lambda 'return id(homeassistant_time).now().timestamp;'
- logger.log: "Turning irrigation 'pump1' on"
- output.turn_on: pump1
- logger.log: "Waiting 20s"
- delay: 20s
- logger.log: "Turning irrigation 'pump1' off"
- output.turn_off: pump1
else:
- logger.log: "Water level is critical - refusing to turn on irrigation"
output:
- platform: gpio
pin:
number: GPIO5
mode:
output: true
pulldown: true
drive_strength: 5mA
id: pump1
- platform: gpio
pin:
number: GPIO6
mode:
output: true
pulldown: true
drive_strength: 5mA
id: pump2
binary_sensor:
- platform: gpio
pin:
number: GPIO4
mode:
input: true
inverted: false
name: "Water Level"
id: water_level
filters:
- delayed_on: 1s
- delayed_off: 1s
on_release:
then:
- logger.log: "Water level critical - turning off all pumps"
- output.turn_off: pump1
- output.turn_off: pump2
sensor:
- platform: uptime
name: "ESP32-C3 Plant Watering Controller Uptime"
- platform: wifi_signal
name: "ESP32-C3 Plant Watering Controller WiFi Signal"
update_interval: 15s
- platform: homeassistant
name: "Soil humidity"
entity_id: sensor.plant_herbs_balcony_soil_moisture
id: plant_herbs_balcony_soil_moisture
text_sensor:
- platform: template
name: "ESP32-C3 Plant Watering Controller Last Run"
icon: mdi:clock-start
lambda: |-
return ESPTime::from_epoch_local(id(last_run)).strftime("%Y-%m-%dT%H:%M:%S");
update_interval: 60s
time:
- platform: homeassistant
id: homeassistant_time
on_time:
- cron: '00 /5 18-6 * * *'
then:
- if:
condition:
and:
- binary_sensor.is_on: water_level
- lambda: |-
return id(plant_herbs_balcony_soil_moisture).state < 55;
- lambda: |-
return id(homeassistant_time).now().is_valid() && (id(homeassistant_time).now().timestamp - id(last_run) > 43200);
then:
- globals.set:
id: last_run
value: !lambda 'return id(homeassistant_time).now().timestamp;'
- logger.log: "Turning irrigation 'pump1' on"
- output.turn_on: pump1
- logger.log: "Waiting 20s"
- delay: 20s
- logger.log: "Turning irrigation 'pump1' off"
- output.turn_off: pump1
else:
- logger.log:
format: "Water level: %d, average soil moisture: %.1f - refusing to water plants"
args: ['id(water_level).state', 'id(weighted_soil_moisture).state']
The PCB does not offer a built-in mechanism to measure soil humidity, but the b-parasite open source project provides a suitable DIY capacitive soil moisture sensor that can easily be integrated using ZigBee / Home Assistant.
The hardware and associated design files are released under the Creative Commons CC BY-SA 4.0 license.