This is the code and documentation repository for a 9 valve sprinkler controller kit based on an ESP32. It has the following features:
- ESP32 Microcontroller
- Uses a 40VA 24VAC wall transformer with an internal fuse.
- Operates the 24 Volt AC sprinkler valves commonly used for irrigation.
- 9 Independently controllable valve outputs.
- 1602 LCD display.
- 3 Front panel buttons.
- Real time clock.
- Individual triac valve drivers rated for 0.4A.
- Monitoring of the total valve current.
- Watchdog relay disconnects all valves if not serviced periodically by the firmware.
- Expansion connector for future valve expanders.
- ABS Plastic Enclosure and graphic overlay.
This hardware is for sale on Tindie It is primarily designed to work with ESPHome firmware version 2023.6.3 or later.
By purchasing and/or using the hardware, you indicate you are using it at your own risk.
The controller is shipped without firmware which can connect to your WIFI network. It will require some firmware programming and electrical knowledge to successfully implement. One should have some experience modifying ESPHome yaml files, reading wiring diagrams, using a Windows or Linux command line shell, using serial devices such as the FTDI serial cable, and using the ESPHome tool to program ESPHome devices. If you are not sure how to program firmware into an ESPHome device, please study the documentation on esphome.com and become familiar with it before purchasing a board. A link to the the programming documentation can be found here
Besides this README.md, there is more documentation in the WIKI
The firmware will need to be provisioned on your controller before you can use it. This is because the WIFI passwords and SSID's will need to be modified so the firmware knows how to log in to your WIFI network.
Note: It is also possible to just upload new firmware, skipping these provisioning steps if you don't want to use improv.
The firmware shipped with the device supports WiFi provisioning (improv) over the serial port (Webserial) using the Google Chrome or Microsoft Edge Broswers.
You'll need a 3.3V USB serial cable to do the provisioning.
Below is the pinout of the serial connector J301.
| PIN | Signal |
|---|---|
| 1 | Ground |
| 2 | No connection |
| 3 | No Connection |
| 4 | RXD referenced to ESP32 |
| 5 | TXD referenced to ESP32 |
| 6 | No Connection |
The location of the serial connector is shown below in Connectors, Pinouts and GPIO's.'
Connect your 3.3V serial adapter to pins 1,4, and 5.Connecting RXD of the adapter to pin 5, TXD of the adapter to pin 4, and ground to pin 1.
Next, open Chrome or Edge and navigate to the following:
Press the "CONNECT" button under "Try a live demo", then select the serial port of the 3.3V serial adapter cable.
You should then see a menu. Choose the "CHANGE WIFI" Menu option.
Enter or choose the network SSID and enter your password.
Click "CONNECT"
You should see a provisioned message after clicking CONNECT.
You are now ready to upload a custom version of ESPHome to the device.
Clone this repository to get the source code for the sprinkler controller.
The firmware consists of ESPHome platform compiled with a user-customizable YAML file and some custom components which are modifications of modules contained in ESPHome.
NOTE: If you wish to configure without using improv to set the WIFI credentials, use the esp32-sprinkler-without-improv.yaml instead of esp32-sprinkler.yaml. Before compiling, rename secrets-sample.yaml to secrets.yaml, and change items in secrets.yaml to suit your requirements.
Once compiled the firmware is installed via a 3.3V serial cable. J201 on the board is a male header which is compatible with FTDI serial cables such as FTDI part number TTL-232R-3V3.
For firmware upload instructions please refer to the wiki
An example YAML file is provided to aid in the implementation of the sprinkler controller. It contains some examples on how to do things with the hardware. Please refer to the file esp32-sprinkler.yaml This file can be used as the basis for your customized yaml file.
One external component are located in the /external_components directory. This is for support of the display. No modification of this external component should be necessary, but it must be present when the firmware is compiled, or there will be compile errors.
There is one custom component located in the /custom_components directory. This external component controls the Valve watchdog relay.No modification of this external component should be necessary, but it must be present when the firmware is compiled, or there will be compile errors.
The hardware can be purchased from me directly.
Hardware included in the kit:
- 1 ea. Main PCB and display
- 1 ea. Pre-drilled enclosure and front panel overlay with 4 retaining screws.
- 1 ea. 2 pin screw terminal pluggable power connector.
- 1 ea. 12 pin screw terminal pluggable power connector.
Not supplied in the kit:
- CR927 battery for the real time clock.
- 3.3V serial adapter for flashing firmware onto the board and connecting cable.
- 24V 40VA transformer
- Wire
- Wood screws for attaching the controller to a backboard
- External connectors (i.e. WAGOs or wire nuts) to common the valve return leads.
Please refer to the [wiki](https://github.com/hwstar/9-Valve-Sprinkler-Controller/wiki] for this reference information.)
The picture below shows the location of the power, valve and serial connectors.
The 2 pin power connector J402 accepts 22-28VAC power at 60Hz from a 40VA wall transformer with an internal fuse (IMPORTANT!). A suitable transformer can be found here
Note: The valves used must not draw more than 0.4 amps each. Do not put more then 1 valve on a valve output pin.
The Serial connector J301 is pinned out to accept an FTDI cable. It is a 1x6 2.54mm pitch header located to the right of the ESP32 module. The serial connector is used to initially upload firmware to the Sprinkler controller
The expansion connector J201 is an 8 pin 3mm pitch Molex micro fit connector (43025 series). It will allow for future expansion of the sprinkler controller to add additional zones.
J302 on the board can be in one of 2 positions. In position 1-2, the battery is connected to the DS1307 clock. In position 2-3 The DS1307 battery input is grounded. The board is shipped with the jumper in positions 2-3. To fully utilize the DS1307, a CR927 battery (not supplied) must be inserted, and the the jumper must be moved to positions 1-2. If the real time clock battery back feature isn't going to be used, the jumper should remain in positions 2-3.
Note: If the jumper is removed or missing, the battery input to the DS1307 will be left floating, and the DS1307 may not be able to be properly accessed via the software.
The display used is a widely available 3.3V 1602 type. It is interfaced to the ESP32 in four bit parallel mode. R310 on the board adjusts the LCD display contrast.
The 3 momentary buttons are connected directly to the ESP32. With associated definitions in the .yaml file, they provide a way to manually initiate operations in case the homeassistant server goes off line.
The watchdog relay will disconnect all the valves if no output toggling is detected on GPIO16. There is an custom component called valve_dog.h which toggles GPIO16 each time the loop function is called. If this output stops toggling, the valves will be disconnected from the 24VAC power source. According to the ESPHome docs, the loop() method in valve_dog.h is called at approximately a 60Hz rate. There is a charge pump on the board connected to a MOSFET which drives the watchdog relay. If the input to the charge pump stops toggling, then the relay opens.
In the .yaml code example and in valve_dog.h the state of the irrigation controller is monitored. If it isn't active, then no toggling will appear on the output of GPIO16, and the relay contacts will be open within 2-6 seconds. Once the irrigation controller becomes active, toggling will appear on GPIO16 and a short time later, the relay will close. This will usually happen within 2 seconds, so that should be factored into the sprinkler controller start delay time.
Note: The watchdog relay should never be used to interrupt power to the valves in normal circumstances. Use the individual valve triacs instead.
The fault LED is controlled by GPIO14. Setting it high turns the fault LED on.
The current sensor connects to GPIO36. It has a sensitivity of 2.02 volts per amp. To get amps RMS, the following formula should be used: Arms = (x/2.02)*0.707 Please note that the ESP32 ADC is not very linear bottom end of its range. The current measurement value should be clipped at the bottom end by using the following code:
if (x < 0.08)
return 0.0;
else
return x;