network.cpp File Reference

This program runs a very simple web server, demonstrating how to serve a static web page and how to use a web link to get the microcontroller to do something simple. More...

#include <Arduino.h>
#include "PrintStream.h"
#include <WiFi.h>
#include <WebServer.h>
#include <shares.h>
#include <taskshare.h>

Functions
Share< bool >	web_calibrate ("Flag to calibrate/zero")
	A share containing a boolean flagging the main script to zero the potentiometers.
IPAddress	local_ip (192, 168, 5, 1)
	Address of ESP32 on its own network.
IPAddress	gateway (192, 168, 5, 1)
	The ESP32 acts as its own gateway.
IPAddress	subnet (255, 255, 255, 0)
	Network mask; just leave this as is.
WebServer	server (80)
	The web server object for this project. More...
void	setup_wifi (void)
	Get the WiFi running so we can serve some web pages. More...
void	HTML_header (String &a_string, const char *page_title)
	Put a web page header into an HTML string. More...
void	handle_DocumentRoot ()
	Callback function that responds to HTTP requests without a subpage name. More...
void	handle_NotFound (void)
	Respond to a request for an HTTP page that doesn't exist. More...
void	handle_Activate (void)
	Switches the state in a FSM when called by the web server. More...
void	handle_Deactivate (void)
	Switches the state in a FSM when called by the web server. More...
void	handle_Calibrate (void)
	Switches the state in a FSM when called by the web server. More...
void	task_webserver (void *p_params)
	Task which sets up and runs a web server. More...

Variables
const char *	ssid = "AirHeads 507"
	SSID, network name seen on LAN lists.
const char *	password = "??what??"
	ESP32 WiFi password (min. 8 characters)

Detailed Description

This program runs a very simple web server, demonstrating how to serve a static web page and how to use a web link to get the microcontroller to do something simple.

Based on an examples by A. Sinha at https://github.com/hippyaki/WebServers-on-ESP32-Codes

Author

A. Sinha

JR Ridgely

Damond Li

Date

2022-Mar-28 Original stuff by Sinha

2022-Nov-04 Modified for ME507 use by Ridgely

2022-Nov-29 Modified for Airheads Glider Project use by Li

Copyright

2022 by the authors, released under the MIT License.

Function Documentation

handle_Activate()

void handle_Activate

(

void

)

Switches the state in a FSM when called by the web server.

This method alters a shared variable that contains the current state of a FSM in the controller task located in main.cpp. The state is switched to 1.

handle_Calibrate()

void handle_Calibrate

(

void

)

Switches the state in a FSM when called by the web server.

This method alters a shared variable that contains the current state of a FSM in the controller task located in main.cpp. The state is switched to 1 and a calibrate boolean is set to true whic will be handled in the controller task.

handle_Deactivate()

void handle_Deactivate

(

void

)

Switches the state in a FSM when called by the web server.

This method alters a shared variable that contains the current state of a FSM in the controller task located in main.cpp. The state is switched to 0.

handle_DocumentRoot()

void handle_DocumentRoot

(

)

Callback function that responds to HTTP requests without a subpage name.

When another computer contacts this ESP32 through TCP/IP port 80 (the insecure Web port) with a request for the main web page, this callback function is run. It sends the main web page's text to the requesting machine.

handle_NotFound()

void handle_NotFound

(

void

)

Respond to a request for an HTTP page that doesn't exist.

This function produces the Error 404, Page Not Found error.

HTML_header()

void HTML_header	(	String &	a_string,
		const char *	page_title
	)

Put a web page header into an HTML string.

This header may be modified if the developer wants some actual style for her or his web page. It is intended to be a common header (and stylle) for each of the pages served by this server.

Parameters

a_string	A reference to a string to which the header is added; the string must have been created in each function that calls this one
page_title	The title of the page

server()

WebServer server

(

80

)

The web server object for this project.

This server is responsible for responding to HTTP requests from other computers, replying with useful information.

It's kind of clumsy to have this object as a global, but that's the way Arduino keeps things simple to program, without the user having to write custom classes or other intermediate-level structures.

setup_wifi()

void setup_wifi

(

void

)

Get the WiFi running so we can serve some web pages.

Function used to setup the wifi on the ESP32.

task_webserver()

void task_webserver

(

void *

p_params

)

Task which sets up and runs a web server.

The webpage task that runs the webpage on the ESP32.

After setup, function handleClient() must be run periodically to check for page requests from web clients. One could run this task as the lowest priority task with a short or no delay, as there generally isn't much rush in replying to web queries.

Parameters

p_params

Pointer to unused parameters