I just implemented an ebb and flow irrigation system, wrote some details here:

In this post the instructions on how to connect a rain sensor ON/OFF type to the hydrosys4 system. This type of sensors are made with a material that expands with water, this expansion trigger the activation of a mechanical switch. Until the material is wet, the switch is OFF (open circuit), so this state can persist for several days until the material dries. The switch is normally closed, when the rain is detected the switch opens. This type of sensor is made to be connected directly in series with the valves, it can controls several valves at same time if it is connected between the valves and the common. This is the easy way to connect it. Anyway in case you want to monitor the activity of the sensor and you want to flexibly associate the valves to be controlled by the rain sensor, it is possible to connect the sensor to the one of the pin of the raspberry set as interrupt. I made a video about the Rain Sensor connection and setting here: https://youtu.be/E51YKMrrR7o Below a summary of the setting: First choose a PIN which is not already present in the "hardwareSetting" table "pin" field. The "hardwaresetting" table indicates the GPIO PIN number. For the Hardware connection just connect the selected RPI pin to one of the Rain sensor wire and the other wire to the ground. For the Software Setting, first you need to create an interrupt to be associated to the GPIO PIN; go to "hardwareSetting" page, click "edit", and in the first row add the following setting: Click "add" and then "confirm and Save" At this point you should be able to see this sensor in the "interrupt" page. Go to "interrupt" page, select the relay you want to be connected to the RainSensor and apply the following setting: When the sensor activates (the circuit opens) an interrupt is triggered, the system will set the relay to zero and start a blocking period of 20 minutes in which any other command to the relay will not take effect. After 20 minutes, it checks the sensor level, if this is still open then it extend the blocking period of other 20 minutes and so on until the sensor closes the circuit and the blocking period is not renewed anymore. The graph will provide the visualization of the blocking period, as in the example below:

Starting from the release 1.16a there is a new feature that can be used in the home page. On the left of each irrigation line name there is a check sign, if you click on the sign it will be changed to "x" and the water line will be deactivated immediately. If the watering line was running, it will be stopped and the line will be inactive until the flag is changed.

After several iterations and data collection, I've created a PCB to neatly connect the Raspberry to the relays/sensors which includes 4 analog inputs to connect analog sensors (0-5v). I called it the "Automatio/Irrigation Hat". I've tested it with several sensors including the analog capacitive hygrometers. Using the analog inputs, among the other things, I can now verify and chart the voltage level of the battery of my Solar irrigation system. The board can be connected to up to 16 relays, which can be irrigation lines or other actuators. The Board is available for sale at the following link: https://www.tindie.com/products/angelova/automationirrigation-hat/ Buying the board can be a great way to contribute to this project. NOTE: the hydrosys4 project can still be implemented without any custom board, all the supported hardware configurations/connections are described in the website.

In case you want to setup more that one system under the same WiFi network, it is required to change the hydrosys4 default IP address in the way that the different systems do not have conflicting IP address. To change the hydrosys4 IP address, go to "Network" click "Advanced Setting" button and change the IP address. You should change only the last IP address number, it is suggested to keep this number in the range between 100 and 200 (e.g 192.168.1.162) It is preferable to make this operation when the the System is not yet connected to the WiFi network. Once you click submit, the IP address will change and the connection with system will be interrupted. Type the new address in the webbrowser and you should be able to connect again. Remember the new IP address will be the default address for the future system access.

Connecting the hydrosys4 system to your home WiFi is a quite straightforward action. Go to the "Network" page, choose your WiFi network among the list of available WiFi network, and insert the password. Anyway although this is going to work in most of the cases, sometimes due to different WiFi setting, it is required to modify the IP address setting of the hydrosys4. In case of problems, the following Router WiFi settings should be verified: 1) Gateway IP address starts with 192.168.1.xx 2) WiFi network uses the WPA2 encryption. In case the Point 1) To understand which IP addresses range your router provides to the attached wifi devices, you can enter your WiFi router setting and check the IP addresses of the dhcp clients. Otherwise you can check IP address of any PC connected to the wifi and see if it starts with 192.168.1. If the three numbers of the IP address are not 192.168.1 (in most cases it might be 192.168.0.), you can experience the following behavior: The WiFi network created by the System (hydrosys4-5172) will disappear, but it is not possible to reach the System under the home WiFi typing the default IP address in the web-browser (192.168.1.172:5172). Most probably the system is successfully connected to the Home WiFi but with different IP address. If you have a Linux or Apple device (windows may also work), first thing you can do is to try to connect with the localhost name, go to the web-browser and type the following address: hydrosys4-172.local:5172. If you can connect to the system using this address then go to the "Network" page and see if there is a Warning Message. If the above address does not work, then restart the system (power OFF - ON) and connect to the System own WiFi network "hydrosys4-5172" within 3 minutes, go to Network page and check if there is a Warning Message. The warning message should include the Gateway IP address where you can check the first 3 numbers. If the first 3 numbers of the Gateway IP address are not 192.168.1.xx you are required to change the Hydrosys4 default IP address. Go to "Network" click "Advanced Setting" button, and change the IP address using same first three numbers of the Gateway IP address. (e.g if the first 3 numbers are 192.168.0, then use the following IP address 192.168.0.172) Once you chick submit, the IP address will change and the connection with system will be interrupted. Type the new address in the web-browser and you should be able to connect. Remember the new IP address will be the default address for the future system access. In case the Point 2) is not verified, then you require to change your WiFi setting. in general is recommended to use the WPA2 encryption for your WiFi security.

The Hydrosys4 SW is by definition ready for internet connectivity, in fact it is based on a web user interface which can be reached by a webbrowser. The web interface is also responsive so it can adapt to PC screen and smartphone tiny displays. Once the system is connected to the Home wifi network or LAN, it is immediately reachable, but what about connecting to the system when outside home? First of all you have to enable the forwarding on your home router, there are tons of examples on google on how to configure it, so I'll not dig on this point. Assuming your router is correclty configured, things are not done yet, now when you are out from home you will require to know your home IP address but you do not know it. Yes right, in most of the cases you do not know it. Well 99.99% of the systems that can be domotics, IP cameras, and whatever network connected device do not use direct connection between the user and the device but the following connection path: The end user (you) connect to a server which is normally run by the same company of the device, this server maintains the user credentials, passwords, and the address of the device. From security and privacy point of view this should be a little concerning but not many people knows this issues. But the internet protocol was definitely meant to connect everybody with everybody directly (or better everything with everything), so there clearly is the possibility for an user to connect directly to a device without passing through a Server, anyway due to unfortunate circumstances the number of IP addresses IPv4 have been all used already some years ago and now the IP service providers use some NAT dynamic addressing to manage this shortage as consequence your home connection does not have a fix (static) IP address anymore. It is like if your Home address (I mean the real address: street name, number, post code) is changes time to time and the postman cannot deliver any message to you unless he knows when and how the address has been changed. To manage the issue the service providers can offer you a static IP address or a DDNS service, and clearly you have to pay an extra for it ... So to recap, service providers get extra Money, company of the devices can get your data, profile you and even sell you data, the end user have just to pay. The good news is that the workarounds to this situation exist, the hydrosys4 SW do not use external servers and can act as a DDNS without making you paying a cent. The funny part is that this is a very easy implementation. If the email is setup, hydrosys4 will send you an email at startup providing its IP address so you can reach the system directly. Around every 15 minutes the system check for its IP address and if it detects that the address has been changes it sends to you an email with the updated address so that it is always reachable. (it has to be notes that the IP address do not change very frequently so the 15 minutes update is more than enough). As you can see, this is Easy and Convenient :). Below an example of email sent by the system, where you can see the link for the remote access: