Source : Random Tutorial
ESP32-CAM Pan and Tilt Video Streaming Web Server (2 Axis)
In this project, we’ll attach the ESP32-CAM to a pan and tilt stand with two SG90 servo motors. With a pan and tilt camera stand, you can move the camera up, down, to the left, and the right— this is great for surveillance. The ESP32-CAM hosts a web server that shows video streaming and buttons to control the servo motors to move the camera.
Boards compatibility: for this project, you need an ESP32 camera development board with
access to two GPIOs to control two servo motors. You can use: ESP32-CAM AI-Thinker, T-Journal or TTGO T-Camera Plus.
Parts Required
For this project, we’ll use the following parts:
- ESP32-CAM AI-Thinker with external antenna
- Pan and tilt stand with SG90 servo motors
- Prototyping circuit board (optional)
- Jumper wires
Pan and Tilt Stand and Motors
For this project, we’ll use a pan and tilt stand that already comes with two SG90 servo motors. The stand is shown in the following figure.
We got our stand from Banggood, but you can get yours from any other store.
Alternatively, you can get two SG90 servo motors and 3D print your own stand.
Servo motors have three wires with different colors:
Wire | Color |
Power | Red |
GND | Black or brown |
Signal | Yellow, orange or white |
How to Control a Servo?
You can position the servo’s shaft at various angles from 0 to 180º. Servos are controlled using a pulse width modulation (PWM) signal. This means that the PWM signal sent to the motor determines the shaft’s position.
To control the servo motor, you can use the PWM capabilities of the ESP32 by sending a signal with the appropriate pulse width. Or you can use a library to make the code simpler. We’ll be using the ESP32Servo library.
Installing the ESP32Servo Library
To control servo motors, we’ll use the ESP32Servo library. Make sure you install that library before proceeding. In your Arduino IDE, go to Sketch > Include Library > Manage Libraries. Search for ESP32Servo and install the library version 0.4.2. At the time of writing this project, more recent versions crash the camera video streaming.
Code
Copy the following code to your Arduino IDE.
/*********
Rui Santos
Complete instructions at https://RandomNerdTutorials.com/esp32-cam-projects-ebook/
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files.
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*********/
#include "esp_camera.h"
#include <WiFi.h>
#include "esp_timer.h"
#include "img_converters.h"
#include "Arduino.h"
#include "fb_gfx.h"
#include "soc/soc.h" // disable brownout problems
#include "soc/rtc_cntl_reg.h" // disable brownout problems
#include "esp_http_server.h"
#include <ESP32Servo.h>
// Replace with your network credentials
const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";
#define PART_BOUNDARY "123456789000000000000987654321"
#define CAMERA_MODEL_AI_THINKER
//#define CAMERA_MODEL_M5STACK_PSRAM
//#define CAMERA_MODEL_M5STACK_WITHOUT_PSRAM
//#define CAMERA_MODEL_M5STACK_PSRAM_B
//#define CAMERA_MODEL_WROVER_KIT
#if defined(CAMERA_MODEL_WROVER_KIT)
#define PWDN_GPIO_NUM -1
#define RESET_GPIO_NUM -1
#define XCLK_GPIO_NUM 21
#define SIOD_GPIO_NUM 26
#define SIOC_GPIO_NUM 27
#define Y9_GPIO_NUM 35
#define Y8_GPIO_NUM 34
#define Y7_GPIO_NUM 39
#define Y6_GPIO_NUM 36
#define Y5_GPIO_NUM 19
#define Y4_GPIO_NUM 18
#define Y3_GPIO_NUM 5
#define Y2_GPIO_NUM 4
#define VSYNC_GPIO_NUM 25
#define HREF_GPIO_NUM 23
#define PCLK_GPIO_NUM 22
#elif defined(CAMERA_MODEL_M5STACK_PSRAM)
#define PWDN_GPIO_NUM -1
#define RESET_GPIO_NUM 15
#define XCLK_GPIO_NUM 27
#define SIOD_GPIO_NUM 25
#define SIOC_GPIO_NUM 23
#define Y9_GPIO_NUM 19
#define Y8_GPIO_NUM 36
#define Y7_GPIO_NUM 18
#define Y6_GPIO_NUM 39
#define Y5_GPIO_NUM 5
#define Y4_GPIO_NUM 34
#define Y3_GPIO_NUM 35
#define Y2_GPIO_NUM 32
#define VSYNC_GPIO_NUM 22
#define HREF_GPIO_NUM 26
#define PCLK_GPIO_NUM 21
#elif defined(CAMERA_MODEL_M5STACK_WITHOUT_PSRAM)
#define PWDN_GPIO_NUM -1
#define RESET_GPIO_NUM 15
#define XCLK_GPIO_NUM 27
#define SIOD_GPIO_NUM 25
#define SIOC_GPIO_NUM 23
#define Y9_GPIO_NUM 19
#define Y8_GPIO_NUM 36
#define Y7_GPIO_NUM 18
#define Y6_GPIO_NUM 39
#define Y5_GPIO_NUM 5
#define Y4_GPIO_NUM 34
#define Y3_GPIO_NUM 35
#define Y2_GPIO_NUM 17
#define VSYNC_GPIO_NUM 22
#define HREF_GPIO_NUM 26
#define PCLK_GPIO_NUM 21
#elif defined(CAMERA_MODEL_AI_THINKER)
#define PWDN_GPIO_NUM 32
#define RESET_GPIO_NUM -1
#define XCLK_GPIO_NUM 0
#define SIOD_GPIO_NUM 26
#define SIOC_GPIO_NUM 27
#define Y9_GPIO_NUM 35
#define Y8_GPIO_NUM 34
#define Y7_GPIO_NUM 39
#define Y6_GPIO_NUM 36
#define Y5_GPIO_NUM 21
#define Y4_GPIO_NUM 19
#define Y3_GPIO_NUM 18
#define Y2_GPIO_NUM 5
#define VSYNC_GPIO_NUM 25
#define HREF_GPIO_NUM 23
#define PCLK_GPIO_NUM 22
#elif defined(CAMERA_MODEL_M5STACK_PSRAM_B)
#define PWDN_GPIO_NUM -1
#define RESET_GPIO_NUM 15
#define XCLK_GPIO_NUM 27
#define SIOD_GPIO_NUM 22
#define SIOC_GPIO_NUM 23
#define Y9_GPIO_NUM 19
#define Y8_GPIO_NUM 36
#define Y7_GPIO_NUM 18
#define Y6_GPIO_NUM 39
#define Y5_GPIO_NUM 5
#define Y4_GPIO_NUM 34
#define Y3_GPIO_NUM 35
#define Y2_GPIO_NUM 32
#define VSYNC_GPIO_NUM 25
#define HREF_GPIO_NUM 26
#define PCLK_GPIO_NUM 21
#else
#error "Camera model not selected"
#endif
#define SERVO_1 14
#define SERVO_2 15
#define SERVO_STEP 5
Servo servoN1;
Servo servoN2;
Servo servo1;
Servo servo2;
int servo1Pos = 0;
int servo2Pos = 0;
static const char* _STREAM_CONTENT_TYPE = "multipart/x-mixed-replace;boundary=" PART_BOUNDARY;
static const char* _STREAM_BOUNDARY = "\r\n--" PART_BOUNDARY "\r\n";
static const char* _STREAM_PART = "Content-Type: image/jpeg\r\nContent-Length: %u\r\n\r\n";
httpd_handle_t camera_httpd = NULL;
httpd_handle_t stream_httpd = NULL;
static const char PROGMEM INDEX_HTML[] = R"rawliteral(
<html>
<head>
<title>ESP32-CAM Robot</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
body { font-family: Arial; text-align: center; margin:0px auto; padding-top: 30px;}
table { margin-left: auto; margin-right: auto; }
td { padding: 8 px; }
.button {
background-color: #2f4468;
border: none;
color: white;
padding: 10px 20px;
text-align: center;
text-decoration: none;
display: inline-block;
font-size: 18px;
margin: 6px 3px;
cursor: pointer;
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
-webkit-tap-highlight-color: rgba(0,0,0,0);
}
img { width: auto ;
max-width: 100% ;
height: auto ;
}
</style>
</head>
<body>
<h1>ESP32-CAM Pan and Tilt</h1>
<img src="" id="photo" >
<table>
<tr><td colspan="3" align="center"><button class="button" onmousedown="toggleCheckbox('up');" ontouchstart="toggleCheckbox('up');">Up</button></td></tr>
<tr><td align="center"><button class="button" onmousedown="toggleCheckbox('left');" ontouchstart="toggleCheckbox('left');">Left</button></td><td align="center"></td><td align="center"><button class="button" onmousedown="toggleCheckbox('right');" ontouchstart="toggleCheckbox('right');">Right</button></td></tr>
<tr><td colspan="3" align="center"><button class="button" onmousedown="toggleCheckbox('down');" ontouchstart="toggleCheckbox('down');">Down</button></td></tr>
</table>
<script>
function toggleCheckbox(x) {
var xhr = new XMLHttpRequest();
xhr.open("GET", "/action?go=" + x, true);
xhr.send();
}
window.onload = document.getElementById("photo").src = window.location.href.slice(0, -1) + ":81/stream";
</script>
</body>
</html>
)rawliteral";
static esp_err_t index_handler(httpd_req_t *req){
httpd_resp_set_type(req, "text/html");
return httpd_resp_send(req, (const char *)INDEX_HTML, strlen(INDEX_HTML));
}
static esp_err_t stream_handler(httpd_req_t *req){
camera_fb_t * fb = NULL;
esp_err_t res = ESP_OK;
size_t _jpg_buf_len = 0;
uint8_t * _jpg_buf = NULL;
char * part_buf[64];
res = httpd_resp_set_type(req, _STREAM_CONTENT_TYPE);
if(res != ESP_OK){
return res;
}
while(true){
fb = esp_camera_fb_get();
if (!fb) {
Serial.println("Camera capture failed");
res = ESP_FAIL;
} else {
if(fb->width > 400){
if(fb->format != PIXFORMAT_JPEG){
bool jpeg_converted = frame2jpg(fb, 80, &_jpg_buf, &_jpg_buf_len);
esp_camera_fb_return(fb);
fb = NULL;
if(!jpeg_converted){
Serial.println("JPEG compression failed");
res = ESP_FAIL;
}
} else {
_jpg_buf_len = fb->len;
_jpg_buf = fb->buf;
}
}
}
if(res == ESP_OK){
size_t hlen = snprintf((char *)part_buf, 64, _STREAM_PART, _jpg_buf_len);
res = httpd_resp_send_chunk(req, (const char *)part_buf, hlen);
}
if(res == ESP_OK){
res = httpd_resp_send_chunk(req, (const char *)_jpg_buf, _jpg_buf_len);
}
if(res == ESP_OK){
res = httpd_resp_send_chunk(req, _STREAM_BOUNDARY, strlen(_STREAM_BOUNDARY));
}
if(fb){
esp_camera_fb_return(fb);
fb = NULL;
_jpg_buf = NULL;
} else if(_jpg_buf){
free(_jpg_buf);
_jpg_buf = NULL;
}
if(res != ESP_OK){
break;
}
//Serial.printf("MJPG: %uB\n",(uint32_t)(_jpg_buf_len));
}
return res;
}
static esp_err_t cmd_handler(httpd_req_t *req){
char* buf;
size_t buf_len;
char variable[32] = {0,};
buf_len = httpd_req_get_url_query_len(req) + 1;
if (buf_len > 1) {
buf = (char*)malloc(buf_len);
if(!buf){
httpd_resp_send_500(req);
return ESP_FAIL;
}
if (httpd_req_get_url_query_str(req, buf, buf_len) == ESP_OK) {
if (httpd_query_key_value(buf, "go", variable, sizeof(variable)) == ESP_OK) {
} else {
free(buf);
httpd_resp_send_404(req);
return ESP_FAIL;
}
} else {
free(buf);
httpd_resp_send_404(req);
return ESP_FAIL;
}
free(buf);
} else {
httpd_resp_send_404(req);
return ESP_FAIL;
}
sensor_t * s = esp_camera_sensor_get();
//flip the camera vertically
//s->set_vflip(s, 1); // 0 = disable , 1 = enable
// mirror effect
//s->set_hmirror(s, 1); // 0 = disable , 1 = enable
int res = 0;
if(!strcmp(variable, "up")) {
if(servo1Pos <= 170) {
servo1Pos += 10;
servo1.write(servo1Pos);
}
Serial.println(servo1Pos);
Serial.println("Up");
}
else if(!strcmp(variable, "left")) {
if(servo2Pos <= 170) {
servo2Pos += 10;
servo2.write(servo2Pos);
}
Serial.println(servo2Pos);
Serial.println("Left");
}
else if(!strcmp(variable, "right")) {
if(servo2Pos >= 10) {
servo2Pos -= 10;
servo2.write(servo2Pos);
}
Serial.println(servo2Pos);
Serial.println("Right");
}
else if(!strcmp(variable, "down")) {
if(servo1Pos >= 10) {
servo1Pos -= 10;
servo1.write(servo1Pos);
}
Serial.println(servo1Pos);
Serial.println("Down");
}
else {
res = -1;
}
if(res){
return httpd_resp_send_500(req);
}
httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");
return httpd_resp_send(req, NULL, 0);
}
void startCameraServer(){
httpd_config_t config = HTTPD_DEFAULT_CONFIG();
config.server_port = 80;
httpd_uri_t index_uri = {
.uri = "/",
.method = HTTP_GET,
.handler = index_handler,
.user_ctx = NULL
};
httpd_uri_t cmd_uri = {
.uri = "/action",
.method = HTTP_GET,
.handler = cmd_handler,
.user_ctx = NULL
};
httpd_uri_t stream_uri = {
.uri = "/stream",
.method = HTTP_GET,
.handler = stream_handler,
.user_ctx = NULL
};
if (httpd_start(&camera_httpd, &config) == ESP_OK) {
httpd_register_uri_handler(camera_httpd, &index_uri);
httpd_register_uri_handler(camera_httpd, &cmd_uri);
}
config.server_port += 1;
config.ctrl_port += 1;
if (httpd_start(&stream_httpd, &config) == ESP_OK) {
httpd_register_uri_handler(stream_httpd, &stream_uri);
}
}
void setup() {
WRITE_PERI_REG(RTC_CNTL_BROWN_OUT_REG, 0); //disable brownout detector
servo1.setPeriodHertz(50); // standard 50 hz servo
servo2.setPeriodHertz(50); // standard 50 hz servo
servoN1.attach(2, 1000, 2000);
servoN2.attach(13, 1000, 2000);
servo1.attach(SERVO_1, 1000, 2000);
servo2.attach(SERVO_2, 1000, 2000);
servo1.write(servo1Pos);
servo2.write(servo2Pos);
Serial.begin(115200);
Serial.setDebugOutput(false);
camera_config_t config;
config.ledc_channel = LEDC_CHANNEL_0;
config.ledc_timer = LEDC_TIMER_0;
config.pin_d0 = Y2_GPIO_NUM;
config.pin_d1 = Y3_GPIO_NUM;
config.pin_d2 = Y4_GPIO_NUM;
config.pin_d3 = Y5_GPIO_NUM;
config.pin_d4 = Y6_GPIO_NUM;
config.pin_d5 = Y7_GPIO_NUM;
config.pin_d6 = Y8_GPIO_NUM;
config.pin_d7 = Y9_GPIO_NUM;
config.pin_xclk = XCLK_GPIO_NUM;
config.pin_pclk = PCLK_GPIO_NUM;
config.pin_vsync = VSYNC_GPIO_NUM;
config.pin_href = HREF_GPIO_NUM;
config.pin_sscb_sda = SIOD_GPIO_NUM;
config.pin_sscb_scl = SIOC_GPIO_NUM;
config.pin_pwdn = PWDN_GPIO_NUM;
config.pin_reset = RESET_GPIO_NUM;
config.xclk_freq_hz = 20000000;
config.pixel_format = PIXFORMAT_JPEG;
if(psramFound()){
config.frame_size = FRAMESIZE_VGA;
config.jpeg_quality = 10;
config.fb_count = 2;
} else {
config.frame_size = FRAMESIZE_SVGA;
config.jpeg_quality = 12;
config.fb_count = 1;
}
// Camera init
esp_err_t err = esp_camera_init(&config);
if (err != ESP_OK) {
Serial.printf("Camera init failed with error 0x%x", err);
return;
}
// Wi-Fi connection
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.print("Camera Stream Ready! Go to: http://");
Serial.println(WiFi.localIP());
// Start streaming web server
startCameraServer();
}
void loop() {
}
Network Credentials
Insert your network credentials and the code should work straight away.
const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";
How the Code Works
Let’s take a look at the relevant parts to control the servo motors.
Define the pins the servo motors are connected to. In this case, they are connected to the ESP32-CAM GPIOs 14 and 15.
#define SERVO_1 14
#define SERVO_2 15
Create Servo objects to control each motor:
Servo servoN1;
Servo servoN2;
Servo servo1;
Servo servo2;
You may be wondering why we are creating four Servo objects when we only have two servos. What happens is that the servo library we’re using automatically assigns a PWM channel to each servo motor (servoN1 → PWM channel 0; servoN2 → PWM channel 1; servo1 → PWM channel 2; servo2 → PWM channel 3).
The first channels are being used by the camera, so if we change those PWM channels’ properties, we’ll get errors with the camera. So, we’ll control servo1 and servo2 that use PWM channels 2 and 3 that are not being used by the camera.
Define the servos initial position.
int servo1Pos = 0;
int servo2Pos = 0;
Web Page
The INDEX_HTML variable contains the HTML text to build the web page. The following lines display the buttons.
<table>
<tr><td colspan="3" align="center"><button class="button" onmousedown="toggleCheckbox('up');" ontouchstart="toggleCheckbox('up');">Up</button></td></tr>
<tr><td align="center"><button class="button" onmousedown="toggleCheckbox('left');" ontouchstart="toggleCheckbox('left');">Left</button></td><td align="center"></td><td align="center"><button class="button" onmousedown="toggleCheckbox('right');" ontouchstart="toggleCheckbox('right');">Right</button></td></tr>
<tr><td colspan="3" align="center"><button class="button" onmousedown="toggleCheckbox('down');" ontouchstart="toggleCheckbox('down');">Down</button></td></tr>
</table>
When you click the buttons, the toggleCheckbox() JavaScript function is called. It makes a request on a different URL depending on the button clicked.
function toggleCheckbox(x) {
var xhr = new XMLHttpRequest();
xhr.open("GET", "/action?go=" + x, true);
xhr.send();
}
Here are the requests made depending on the button that is being pressed:
Up:
/action?go=up
Down:
/action?go=down
Left:
/action?go=left
Right:
/action?go=right
Handle Requests
Then, we need to handle what happens when we get those requests. That’s what’s done in the following lines.
if(!strcmp(variable, "up")) {
if(servo1Pos <= 170) {
servo1Pos += 10;
servo1.write(servo1Pos);
}
Serial.println(servo1Pos);
Serial.println("Up");
}
else if(!strcmp(variable, "left")) {
if(servo2Pos <= 170) {
servo2Pos += 10;
servo2.write(servo2Pos);
}
Serial.println(servo2Pos);
Serial.println("Left");
}
else if(!strcmp(variable, "right")) {
if(servo2Pos >= 10) {
servo2Pos -= 10;
servo2.write(servo2Pos);
}
Serial.println(servo2Pos);
Serial.println("Right");
}
else if(!strcmp(variable, "down")) {
if(servo1Pos >= 10) {
servo1Pos -= 10;
servo1.write(servo1Pos);
}
Serial.println(servo1Pos);
Serial.println("Down");
}
To move a motor, call the write() function on the servo1 or servo2 objects and pass the angle (0 to 180) as an argument. For example:
servo1.write(servo1Pos);
setup()
In the setup(), set the servo motor properties: define the signal frequency.
servo1.setPeriodHertz(50); // standard 50 hz servo
servo2.setPeriodHertz(50); // standard 50 hz servo
Use the attach() method to set the servo GPIO and minimum and maximum pulse width in microseconds.
servo1.attach(SERVO_1, 1000, 2000);
servo2.attach(SERVO_2, 1000, 2000);
Set the motors to its initial position when the ESP32 first boots.
servo1.write(servo1Pos);
servo2.write(servo2Pos);
That’s pretty much how the code works when it comes to control the servo motors.
Testing the Code
After inserting your network credentials, you can upload the code to your board. You can use an FTDI programmer or an ESP32-CAM MB programmer. Read one of the following articles:
- How to Program / Upload Code to ESP32-CAM AI-Thinker (Arduino IDE) (FTDI)
- Upload Code to ESP32-CAM AI-Thinker using ESP32-CAM-MB USB Programmer (easiest way)
After uploading, open the Serial Monitor to get the board IP address.
Note: if you’re using an FTDI programmer, don’t forget to disconnect GPIO 0 from GND before opening the Serial Monitor.
Open a browser and type the board IP address to get access to the web server. Click on the buttons and check on the Serial Monitor if everything seems to be working as expected.
If everything is working as expected you can wire the servo motors to the ESP32-CAM and continue with the project.
Circuit
After assembling the pan and tilt stand, connect the servo motors to the ESP32-CAM as shown in the following schematic diagram. We’re connecting the servo motor data pins to GPIO 15 and GPIO 14.
You can use a mini breadboard to assemble the circuit or build a mini stripboard with header pins to connect power, the ESP32-CAM, and the motors, as shown below.
The following figure shows how the pan and tilt stands looks like after assembling.
Demonstration
Apply power to your board. Open a browser and type the ESP32-CAM IP address. A web page with real-time video streaming should load. Click the buttons to move the camera up, down, left, or right.
You can move the camera remotely using the buttons on the web page. This allows you to
monitor a different area accordingly to the camera position. This is a great solution for surveillance applications.
Wrapping Up
In this tutorial, you’ve learned how to build a pan and tilt web server with video streaming to control the ESP32-CAM.
Controlling servo motors with the ESP32-CAM is the same as controlling them using a “regular” ESP32. You can read the following tutorial to learn more about servo motors with the ESP32:
If you want to control your robot outside the range of your local network, you might consider setting the ESP32-CAM as an access point. This way, the ESP32-CAM doesn’t need to connect to your router. It creates its own wi-fi network, and nearby wi-fi devices like your smartphone can connect to it.
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