Microprocessor 2 Labs v2.0
Microprocessor 2 Lab Documenation
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Additional Labs

These are additional labs that may or may not be used in the course. The following labs consist of using ESP22 IOT interface with an http server.

Labs

Additional Lab GitHub

Additional Labs Repository

Lab 9 WiFi and Internet of Things (IOT)

Objective

  • Using the provided code, create a soft access point. Use your last name as the ssid and your ID as password
  • Edit the http_server_netconn_serveso that you blink an LED every time the button 0 is pressed in the webpage.
  • The webpage included in the provided code is shown in Figure 1.

Bonus

  • Create your own HTML page for the server. +20

Template Code

#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event_loop.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "driver/gpio.h"
#include "lwip/sys.h"
#include "lwip/netdb.h"
#include "lwip/api.h"
const static char http_html_hdr[] = "HTTP/1.1 200 OK\r\nContent-type: text/html\r\n\r\n";
const static char http_html_txt[] = "HTTP/1.1 200 OK\r\nContent-type: text/plain\r\n\r\n";
const static char http_index_hml[] = R"=====(<!DOCTYPE html><html> <head> <meta charset = UTF-8
name = "viewport" content = "width = device-width initial-scale = 1.0"> <title>Home Page</title> </head>
<body> <div class="header"> <h1>Home Page</h1> </div> <input class = "btn" id = "btn0" type="button"
value = "BTN0" onclick = "sendRequest()"> <input class = "btn" id = "btn1" type="button" value = "get
data" onclick = "sendRequest()"> <div class="sensorVal"> <p>Sensor Value: </p> <div id="sen"></div>
</div> <style> *{margin:0; padding:0;} body {background-color: #D4DCE2;} .header { width:100%;
height:55px; color: white; background-color: #04254D; padding: 0; text-align:center; } .header h1{
color:white; vertical-align:center; font-size:42px; } .btn { margin: 0; margin-top: .5%; background-color:
#FB9541; width:48%; border: none; color: white; padding: 25px 38px; text-align: center; text-decoration:
none; font-size: 16px; } .sensorVal { margin: 0; margin-top: .5%; width:100%; height:70px; color: white;
background-color: #04254D; padding: 0; text-align:center; } .sensorVal p{ color:white; vertical-align:center;
font-size:38px; } </style> <script> function changeButton(value){ var btn =
document.getElementById("btn0"); if(value === "0"){ btn.value = "LED is OFF"; } else{ btn.value = "LED is
ON"; } } function sendRequest(){ var http = new XMLHttpRequest(); http.onreadystatechange = (()=>{
if(http.readyState === 4){ if(http.status === 200){ changeButton(http.responseText); } } });
http.open("GET", "btn0", true); http.send(); } // function sendRequest1(){ // var http = new
XMLHttpRequest(); // http.onreadystatechange = (()=>{ // if(http.readyState === 4){ // if(http.status ===
200){ // document.getElementById("sen").innerText = http.responseText; // } // } // }); // http.open("GET",
"data", true); // http.send(); // } // setInterval(sendRequest1, 1000); </script> </body></html>)=====";
#define EXAMPLE_ESP_WIFI_SSID ""
#define EXAMPLE_ESP_WIFI_PASS ""
#define EXAMPLE_MAX_STA_CONN 1
static EventGroupHandle_t s_wifi_event_group;
static const char *TAG = "wifi softAP";
static esp_err_t event_handler(void *ctx, system_event_t *event)
{
switch (event->event_id)
{
case SYSTEM_EVENT_AP_STACONNECTED:
ESP_LOGI(TAG, "station:" MACSTR " join, AID=%d",
MAC2STR(event->event_info.sta_connected.mac),
event->event_info.sta_connected.aid);
break;
case SYSTEM_EVENT_AP_STADISCONNECTED:
ESP_LOGI(TAG, "station:" MACSTR "leave, AID=%d",
MAC2STR(event->event_info.sta_disconnected.mac),
event->event_info.sta_disconnected.aid);
break;
default:
break;
}
return ESP_OK;
}
void wifi_init_softap()
{
s_wifi_event_group = xEventGroupCreate();
tcpip_adapter_init();
ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
ESP_ERROR_CHECK(esp_wifi_init(&cfg));
wifi_config_t wifi_config = {
.ap = {
.ssid = EXAMPLE_ESP_WIFI_SSID,
.ssid_len = strlen(EXAMPLE_ESP_WIFI_SSID),
.password = EXAMPLE_ESP_WIFI_PASS,
.max_connection = EXAMPLE_MAX_STA_CONN,
.authmode = WIFI_AUTH_WPA_WPA2_PSK},
};
if (strlen(EXAMPLE_ESP_WIFI_PASS) == 0)
{
wifi_config.ap.authmode = WIFI_AUTH_OPEN;
}
ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &wifi_config));
ESP_ERROR_CHECK(esp_wifi_start());
ESP_LOGI(TAG, "wifi_init_softap finished.SSID:%s password:%s",
EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
}
static void http_server_netconn_serve(struct netconn *conn)
{
struct netbuf *inbuf;
char *buf;
u16_t buflen;
err_t err;
/* Read the data from the port, blocking if nothing yet there.
We assume the request (the part we care about) is in one netbuf */
err = netconn_recv(conn, &inbuf);
if (err == ERR_OK)
{
netbuf_data(inbuf, (void **)&buf, &buflen);
/* Is this an HTTP GET command? (only check the first 5 chars, since
there are other formats for GET, and we're keeping it very simple )*/
if (buflen >= 5 &&
buf[0] == 'G' &&
buf[1] == 'E' &&
buf[2] == 'T' &&
buf[3] == ' ' &&
buf[4] == '/')
{
printf("%c\n", buf[5]);
/* Send the HTML header
* subtract 1 from the size, since we dont send the \0 in the string
* NETCONN_NOCOPY: our data is const static, so no need to copy it
*/
// command from button 1 is 'b'
if (buf[5])
{
// send anything back
netconn_write(conn, http_html_txt, sizeof(http_html_hdr) - 1, NETCONN_NOCOPY);
netconn_write(conn, "1", 1, NETCONN_NOCOPY);
}
else
{
// else send original home page
netconn_write(conn, http_html_hdr, sizeof(http_html_hdr) - 1, NETCONN_NOCOPY);
netconn_write(conn, http_index_hml, sizeof(http_index_hml) - 1, NETCONN_NOCOPY);
}
}
}
netconn_close(conn);
netbuf_delete(inbuf);
}
static void http_server(void *pvParameters)
{
struct netconn *conn, *newconn;
err_t err;
conn = netconn_new(NETCONN_TCP);
netconn_bind(conn, NULL, 80);
netconn_listen(conn);
do
{
err = netconn_accept(conn, &newconn);
if (err == ERR_OK)
{
http_server_netconn_serve(newconn);
netconn_delete(newconn);
}
} while (err == ERR_OK);
netconn_close(conn);
netconn_delete(conn);
}
void app_main()
{
nvs_flash_init();
wifi_init_softap();
xTaskCreate(&http_server, "http_server", 2048, NULL, 5, NULL);
EXAMPLE_ESP_WIFI_SSID
#define EXAMPLE_ESP_WIFI_SSID
Definition main.c:135
app_main
void app_main()
Definition main.c:261
EXAMPLE_ESP_WIFI_PASS
#define EXAMPLE_ESP_WIFI_PASS
Definition main.c:136
EXAMPLE_MAX_STA_CONN
#define EXAMPLE_MAX_STA_CONN
Definition main.c:163
wifi_init_softap
void wifi_init_softap()
Definition main.c:197

Lab 9 GitHub

Lab 9 Repository

Lab 10 WiFi and Internet of Things (IOT): Servo Motor Control

Objective

  • Using the provided code, create a soft access point. Use your last name as the ssid and your ID as password
  • Initialize a pwm channel to be able to control a servo motor from a website
  • Edit the http_server_netconn_serveso that you blink an LED every time the button 0 is pressed in the webpage.
  • The webpage included in the provided code is shown in Figure 1.

Bonus

  • Create your own HTML page for the server. +20

Template Code

#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event_loop.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "driver/gpio.h"
#include "driver/ledc.h"
#include "lwip/sys.h"
#include "lwip/netdb.h"
#include "lwip/api.h"
const static char http_html_hdr[] = "HTTP/1.1 200 OK\r\nContent-type: text/html\r\n\r\n";
const static char http_html_hdr1[] = "HTTP/1.1 200 OK\r\nContent-type: text/plain\r\n\r\n";
const static char http_index_hml[] = R"=====(<!DOCTYPE html><html> <head> <meta charset = UTF-8
name = "viewport" content = "width = device-width initial-scale = 1.0"> <title>Home Page</title> </head>
<body> <div class="header"> <h1>Home Page</h1> </div> <input class = "btn" id = "btn0" type="button"
value = "BTN0" onclick = "sendRequest()"> <input class = "btn" id = "btn1" type="button" value = "BTN1"
onclick = "sendRequest1()"> <div class="sensorVal"> <p>Sensor Value: </p> <div id="sen"></div> </div>
<style> *{margin:0; padding:0;} body {background-color: #D4DCE2;} .header { width:100%; height:55px;
color: white; background-color: #04254D; padding: 0; text-align:center; } .header h1{ color:white; vertical␂align:center; font-size:42px; } .btn { margin: 0; margin-top: .5%; background-color: #FB9541; width:48%;
border: none; color: white; padding: 25px 38px; text-align: center; text-decoration: none; font-size: 16px; }
.sensorVal { margin: 0; margin-top: .5%; width:100%; height:70px; color: white; background-color:
#04254D; padding: 0; text-align:center; } .sensorVal p{ color:white; vertical-align:center; font-size:38px; }
</style> <script> function sendRequest(){ var http = new XMLHttpRequest(); http.onreadystatechange =
(()=>{ if(http.readyState === 4){ if(http.status === 200){ var res = http.responseText; } } });
http.open("GET", "0", true); http.send(); } function sendRequest1(){ var http = new XMLHttpRequest();
http.onreadystatechange = (()=>{ if(http.readyState === 4){ if(http.status === 200){ var res =
http.responseText; } } }); http.open("GET", "1", true); http.send(); } </script> </body></html>)=====";
#define EXAMPLE_ESP_WIFI_SSID ""
#define EXAMPLE_ESP_WIFI_PASS ""
#define EXAMPLE_MAX_STA_CONN 1
static EventGroupHandle_t s_wifi_event_group;
static const char *TAG = "wifi softAP";
static esp_err_t event_handler(void *ctx, system_event_t *event)
{
switch (event->event_id)
{
case SYSTEM_EVENT_AP_STACONNECTED:
ESP_LOGI(TAG, "station:" MACSTR " join, AID=%d",
MAC2STR(event->event_info.sta_connected.mac),
event->event_info.sta_connected.aid);
break;
case SYSTEM_EVENT_AP_STADISCONNECTED:
ESP_LOGI(TAG, "station:" MACSTR "leave, AID=%d",
MAC2STR(event->event_info.sta_disconnected.mac),
event->event_info.sta_disconnected.aid);
break;
default:
break;
}
return ESP_OK;
}
void wifi_init_softap()
{
s_wifi_event_group = xEventGroupCreate();
tcpip_adapter_init();
ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
ESP_ERROR_CHECK(esp_wifi_init(&cfg));
wifi_config_t wifi_config = {
.ap = {
.ssid = EXAMPLE_ESP_WIFI_SSID,
.ssid_len = strlen(EXAMPLE_ESP_WIFI_SSID),
.password = EXAMPLE_ESP_WIFI_PASS,
.max_connection = EXAMPLE_MAX_STA_CONN,
.authmode = WIFI_AUTH_WPA_WPA2_PSK},
};
if (strlen(EXAMPLE_ESP_WIFI_PASS) == 0)
{
wifi_config.ap.authmode = WIFI_AUTH_OPEN;
}
ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &wifi_config));
ESP_ERROR_CHECK(esp_wifi_start());
ESP_LOGI(TAG, "wifi_init_softap finished.SSID:%s password:%s", EXAMPLE_ESP_WIFI_SSID,
EXAMPLE_ESP_WIFI_PASS);
}
static void http_server_netconn_serve(struct netconn *conn)
{
struct netbuf *inbuf;
char *buf;
u16_t buflen;
err_t err;
/* Read the data from the port, blocking if nothing yet there.
We assume the request (the part we care about) is in one netbuf */
err = netconn_recv(conn, &inbuf);
if (err == ERR_OK)
{
netbuf_data(inbuf, (void **)&buf, &buflen);
/* Is this an HTTP GET command? (only check the first 5 chars, since
there are other formats for GET, and we're keeping it very simple )*/
if (buflen >= 5 &&
buf[0] == 'G' &&
buf[1] == 'E' &&
buf[2] == 'T' &&
buf[3] == ' ' &&
buf[4] == '/')
{
printf("%c\n", buf[5]);
/* Send the HTML header
* subtract 1 from the size, since we dont send the \0 in the string
* NETCONN_NOCOPY: our data is const static, so no need to copy it
*/
// command from btn0 = '0' command from btn1 = '1'
if (buf[5] == '0')
{
}
if (buf[5] == '1')
{
}
else
{
netconn_write(conn, http_html_hdr, sizeof(http_html_hdr) - 1, NETCONN_NOCOPY);
netconn_write(conn, http_index_hml, sizeof(http_index_hml) - 1, NETCONN_NOCOPY);
}
}
}
netconn_close(conn);
netbuf_delete(inbuf);
}
static void http_server(void *pvParameters)
{
struct netconn *conn, *newconn;
err_t err;
conn = netconn_new(NETCONN_TCP);
netconn_bind(conn, NULL, 80);
netconn_listen(conn);
do
{
err = netconn_accept(conn, &newconn);
if (err == ERR_OK)
{
http_server_netconn_serve(newconn);
netconn_delete(newconn);
}
} while (err == ERR_OK);
netconn_close(conn);
netconn_delete(conn);
}
void setUpPWM()
{
}
void app_main()
{
nvs_flash_init();
wifi_init_softap();
setUpPWM();
xTaskCreate(&http_server, "http_server", 2048, NULL, 5, NULL);
}
setUpPWM
void setUpPWM()
Definition main.c:303

Lab 10 GitHub

Lab 10 Repository

Lab 11 WiFi and Internet of Things (IOT): ADC Monitor

Goals

  • Using the provided code, create a soft access point. Use your last name as the ssid and your ID as password.
  • Initialize an ADC channel to measure a voltage and visualize it in the provided website.
  • Edit the code so that you blink an LED when the user pressbutton 0 and gets data when the user presses the get data button.
  • Button 0 must also return the current state of the LED (0 or 1 for on and off)

Bonus

  • Display the voltage value rather than the bit value. +10

Template Code

#include <string.h>
#include <math.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event_loop.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "driver/gpio.h"
#include "driver/adc.h"
#include "lwip/sys.h"
#include "lwip/netdb.h"
#include "lwip/api.h"
const static char http_html_hdr[] = "HTTP/1.1 200 OK\r\nContent-type: text/html\r\n\r\n";
const static char http_txt_hdr[] = "HTTP/1.1 200 OK\r\nContent-type: text/plain\r\n\r\n";
const static char http_index_hml[] = R"=====(<!DOCTYPE html><html> <head> <meta charset = UTF-8
name = "viewport" content = "width = device-width initial-scale = 1.0"> <title>Home Page</title> </head>
<body> <div class="header"> <h1>Home Page</h1> </div> <input class = "btn" id = "btn0" type="button"
value = "BTN0" onclick = "sendRequestLed()"> <input class = "btn" id = "btn1" type="button" value = "get
data" onclick = "sendRequestData()"> <div class="sensorVal"> <p>Sensor Value: </p> <p id="sen"></p>
</div> <style> *{margin:0; padding:0;} body {background-color: #D4DCE2;} .header { width:100%;
height:55px; color: white; background-color: #04254D; padding: 0; text-align:center; } .header h1{
color:white; vertical-align:center; font-size:42px; } .btn { margin: 0; margin-top: .5%; background-color:
#FB9541; width:48%; border: none; color: white; padding: 25px 38px; text-align: center; text-decoration:
none; font-size: 16px; } .sensorVal { margin: 0; margin-top: .5%; width:100%; height:70px; color: white;
background-color: #04254D; padding: 0; text-align:center; } .sensorVal p{ color:white; vertical-align:center;
font-size:38px; } </style> <script> function changeButton(value){ var btn =
document.getElementById("btn0"); if(value === "0"){ btn.value = "LED is OFF"; } else{ btn.value = "LED is
ON"; } } function sendRequestLed(){ var http = new XMLHttpRequest(); http.onreadystatechange = (()=>{
if(http.readyState === 4){ if(http.status === 200){ changeButton(http.responseText); } } });
http.open("GET", "0", true); http.send(); } function sendRequestData(){ var http = new XMLHttpRequest();
http.onreadystatechange = (()=>{ if(http.readyState === 4){ if(http.status === 200){
document.getElementById("sen").innerHTML = http.responseText; } } }); http.open("GET", "1", true);
http.send(); } // setInterval(sendRequest1, 1000); </script> </body></html>)=====";
#define EXAMPLE_ESP_WIFI_SSID ""
#define EXAMPLE_ESP_WIFI_PASS ""
#define EXAMPLE_MAX_STA_CONN 1
static EventGroupHandle_t s_wifi_event_group;
void wifi_init_softap()
{
s_wifi_event_group = xEventGroupCreate();
tcpip_adapter_init();
ESP_ERROR_CHECK(esp_event_loop_init(NULL, NULL));
wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
ESP_ERROR_CHECK(esp_wifi_init(&cfg));
wifi_config_t wifi_config = {
.ap = {
.ssid = EXAMPLE_ESP_WIFI_SSID,
.ssid_len = strlen(EXAMPLE_ESP_WIFI_SSID),
.password = EXAMPLE_ESP_WIFI_PASS,
.max_connection = EXAMPLE_MAX_STA_CONN,
.authmode = WIFI_AUTH_WPA_WPA2_PSK},
};
if (strlen(EXAMPLE_ESP_WIFI_PASS) == 0)
{
wifi_config.ap.authmode = WIFI_AUTH_OPEN;
}
ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &wifi_config));
ESP_ERROR_CHECK(esp_wifi_start());
}
void onURL(struct netconn *conn, char command)
{
if (command == '0')
{
}
else if (command == '1')
{
}
else
{
netconn_write(conn, http_html_hdr, sizeof(http_html_hdr) - 1, NETCONN_NOCOPY);
netconn_write(conn, http_index_hml, sizeof(http_index_hml) - 1, NETCONN_NOCOPY);
}
}
static void http_server_netconn_serve(struct netconn *conn)
{
struct netbuf *inbuf;
char *buf;
u16_t buflen;
err_t err;
/* Read the data from the port, blocking if nothing yet there.
We assume the request (the part we care about) is in one netbuf */
err = netconn_recv(conn, &inbuf);
if (err == ERR_OK)
{
netbuf_data(inbuf, (void **)&buf, &buflen);
/* Is this an HTTP GET command? (only check the first 5 chars, since
there are other formats for GET, and we're keeping it very simple )*/
if (buflen >= 5 &&
buf[0] == 'G' &&
buf[1] == 'E' &&
buf[2] == 'T' &&
buf[3] == ' ' &&
buf[4] == '/')
{
/* Send the HTML header
* subtract 1 from the size, since we dont send the \0 in the string
* NETCONN_NOCOPY: our data is const static, so no need to copy it
*/
onURL(conn, buf[5]);
}
}
netconn_close(conn);
netbuf_delete(inbuf);
}
static void http_server(void *pvParameters)
{
struct netconn *conn, *newconn;
err_t err;
conn = netconn_new(NETCONN_TCP);
netconn_bind(conn, NULL, 80);
netconn_listen(conn);
do
{
err = netconn_accept(conn, &newconn);
if (err == ERR_OK)
{
http_server_netconn_serve(newconn);
netconn_delete(newconn);
}
} while (err == ERR_OK);
netconn_close(conn);
netconn_delete(conn);
}
void setADC()
{
}
void app_main()
{
nvs_flash_init();
setADC();
wifi_init_softap();
xTaskCreate(&http_server, "http_server", 2048, NULL, 5, NULL);
}
setADC
void setADC()
Definition main.c:304
onURL
void onURL(struct netconn *conn, char command)
Definition main.c:216

Lab 11 GitHub

Lab 11 Repository

Authors

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