IonoWeb

This library provides functions to control and monitor iono ethernet via a HTTP-based API.

The library provides the following methods:

IonoWeb.begin(int port)

Start the Web server on the specified port number.

IonoWeb.processRequest()

This method must be called periodically (inside the loop() function) in order serve the incoming HTTP requests.

IonoWeb.subscribeDigital(int pin, unsigned long stableTime, char *host, int port, char *command)

This method can be used to have iono make a HTTP request to a remote host whenever a digital input changes state.
After calling this method, every time the specified pin changes state and maintains such state at least for a time equal to stableTime (in milliseconds), iono will perform a HTTP request to the specified port of the specified host with the string command as a path:

An occurrence of "$pin" or "$val" in the string command will be respectively substituted by the name of the pin and its current value.

For instance, after calling:

IonoWeb.subscribeDigital(DI1, 500, "192.168.0.200", 8080, "/foo?$pin=$val");

if the input DI1 goes high and stays high for 500 ms, iono will perform a HTTP request equivalent to this:

http://192.168.0.200:8080/foo?DI1=1

IonoWeb.subscribeAnalog(int pin, unsigned long stableTime, float minVariation, char *host, int port, char *command)

This method can be used to have iono make a HTTP request to a remote host whenever an analog input changes state.
After calling this method, every time the specified pin changes value of an amount equal or bigger than the minVariation parameter and maintains such state at least for a time equal to stableTime (in milliseconds), iono will perform a HTTP request to the specified port of the specified host with the string command as a path:

An occurrence of "$pin" or "$val" in the string command will be respectively substituted by the name of the pin and its current value.

For instance, after calling:

IonoWeb.subscribeAnalog(AV2, 0, 1, "192.168.0.200", 8080, "/bar?$pin=$val");

if the voltage on AV2 changes of a value greater or equal to 1V (e.g. from 4V to 5.4V), iono will perform a HTTP request equivalent to this:

http://192.168.0.200:8080/bar?AV2=5.40

IonoWeb.getWebServer()

This method can be used to obtain a reference to the underlying WebServer object.

## HTTP API The HTTP API provides for the following three actions:

/api/state

Making a HTTP request to this path, like the following:

http://192.168.0.100/api/state

will return a JSON object with the following format:

{
    "DO1": <do1_val>,
    "DO2": <do2_val>,
    "DO3": <do3_val>,
    "DO4": <do4_val>,
    "DO5": <do5_val>,
    "DO6": <do6_val>,
    "I1": {
        "D": <di1_val>,
        "V": <av1_val>,
        "I": <ai1_val>
    },
    "I2": {
        "D": <di2_val>,
        "V": <av2_val>,
        "I": <ai2_val>
    },
    "I3": {
        "D": <di3_val>,
        "V": <av3_val>,
        "I": <ai3_val>
    },
    "I4": {
        "D": <di4_val>,
        "V": <av4_val>,
        "I": <ai4_val>
    },
    "I5": {
        "D": <di5_val>
    },
    "I6": {
        "D": <di6_val>
    }
}

which reports the current value of iono's pins.

/api/set

An HTTP request to this path with a set of pairs <pin_name>=<val> as parameters can be used to control iono's outputs.
Here is a few examples:

http://192.168.0.100/api/set?DO1=1
http://192.168.0.100/api/set?DO1=0&DO4=f
http://192.168.0.100/api/set?DO1=0&DO2=1&DO3=0&DO4=1&DO5=0&DO6=0&AO1=7.3

For digital outputs the allowed values are '0' (low), '1' (high) or 'f' (flip the current state); for analog ones, the allowed values are floating numbers from 0.0 to 10.0.

/api/subscribe

This HTTP request must be used following this format:

http://192.168.0.100/api/subscribe?pin=<pin_name>&st=<time>&mv=<var>&host=<host>&port=<port>&cmd=<command>

The above request corresponds to a call to one of the following methods, depending on the pin:

IonoWeb.subscribeDigital(<pin_name>, <time>, <host>, <port>, <command>);
IonoWeb.subscribeAnalog(<pin_name>, <time>, <var>, <host>, <port>, <command>);

For instance, after making this request:

http://192.168.0.100/api/subscribe?pin=DI1&st=500&host=192.168.0.200&port=8080&cmd=/foo?$pin=$val

every time the input DI1 will go high and stay high for 500ms the following request will be triggered:

http://192.168.0.200:8080/foo?DI1=1

Examples

The library folder includes some examples that can be opened directly from the Arduino IDE menu File > Examples > IonoWeb.

• API shows how to use the HTTP API;
• SubscribeWeb shows how to use the subscribe methods to monitor inputs;
• WebApp implements a complete Web application to control, monitor and configure iono. See next paragraph for more details.

WebApp

To access the Web interface provided by this sketch, open a browser and go to http://192.168.0.100/

The six switches DO1 ... DO6 control the corresponding iono's relays; the table shows the current state of its inputs and the AO1 field can be used to change the voltage of the analog output.

To access the configuration panel, click on the icon on the top-right corner. Here it will be possible to modify iono's configuration (IP, DNS, Gateway, Subnet, MAC address and password to access the Web interface).

Moreover, this sketch provides for a procedure to reset iono's configuration. To this end, power off iono, short-circuit pins RX and TX and power it back on. Now go to http://192.168.0.100/, set the new configuration and save, wait for the process to complete and remove the short-circuit.