![\"ESP32](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2022\/03\/MicroPython-OTA-Updates-PHP-Server.jpg?resize=1200%2C675&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nThis project was created by one of our readers: David Flory<\/em>. Thank you for your contributions. He provided the example codes and some explanations, and we’re documenting the whole process in this tutorial.<\/p>\n\n\n\n Note<\/strong>: for the latest version of his OTA project, please check this repository on his GitHub page<\/a>.<\/p>\n\n\n\n Not familiar with MicroPython? Start here<\/a>.<\/p>\n\n\n\n OTA (Over-the-Air) update is the process of loading new firmware to the ESP32 or ESP8266 board using a Wi-Fi connection rather than a serial communication. This functionality is extremely useful in case of no physical access to the board.<\/p>\n\n\n\n There are different ways to perform OTA updates. We have several examples for OTA updates using the ESP32\/ESP8266 boards with Arduino IDE<\/a>. In this tutorial, we’ll create a PHP server that will host new\/updated code. The ESP will periodically communicate with the server to check if there is a new updated code available and download it to the board if that’s the case.<\/p>\n\n\n\n The following diagram explains how everything works.<\/p>\n\n\n Alternative method:<\/strong><\/p>\n\n\n\n Here’s an alternative method that doesn’t require deleting previous files and allows you to update multiple boards.<\/p>\n\n\n\n We provide the files for this method at the end of the tutorial.<\/p>\n\n\n\n Taking it further:<\/strong><\/p>\n\n\n\n A better way to do it might be to create an SQL database on your server, with a record for each ESP with fields for ID (could be MAC address), the version running, time file downloaded (instructions not included).<\/p>\n\n\n\n The PHP could be adjusted to:<\/p>\n\n\n\n Before proceeding, make sure you check the following prerequisites.<\/p>\n\n\n\n In this tutorial, we’ll program the ESP32\/ESP8266 boards using MicroPython. Your boards must be burned with MicroPython firmware and you must have a MicroPython IDE to program your boards. We’ll use Thonny IDE<\/a>, but you can use any other MicroPython-compatible software.<\/p>\n\n\n\n The ESP will communicate with the PHP server periodically to check if there are any updates (a new file with a new MicroPython code). You can create a local PHP server on a Raspberry Pi, for example, or alternatively, you can create a PHP server on the cloud (hosting + domain name) that can be accessed from anywhere.<\/p>\n\n\n\n For this example, we’ll create a local PHP server on a Raspberry Pi. So, you also need a Raspberry Pi for this tutorial:<\/p>\n\n\n\n After getting a Raspberry Pi, follow the next instructions to set it up:<\/p>\n\n\n\n We’ll provide the instructions to create the local PHP server in this tutorial. You’ll also need a way to upload files to your PHP server remotely. We’ll use Filezilla<\/a>. You can use any other suitable method. <\/p>\n\n\n\n Alternatively, you can create your PHP server on the cloud using web hosting and a domain name. We recommend Bluehost <\/a>or Digital Ocean<\/a>. This tutorial doesn’t provide the instructions for this, but if you’re familiar with hosting your PHP server, you’ll easily figure out how to do it.<\/p>\n\n\n\n In this tutorial, we’ll create a local PHP server on a Raspberry Pi. Alternatively, you can create a cloud PHP server (instructions not included).<\/p>\n\n\n\n Before proceeding make sure you have installed the Raspberry Pi OS, set up Wi-Fi and SSH<\/a>.<\/p>\n\n\n\n You can either run the next commands on a Raspberry Pi set as a desktop computer or using an SSH connection<\/a>.<\/p>\n\n\n\n Run the following commands to update your Pi. It will take a few minutes to complete.<\/p>\n\n\n\n Change permissions so that the pi user can make modifications to files.<\/p>\n\n\n\n Next, install Apache2. Apache2 is the most widely used web server software. To install Apache2 on your Raspberry Pi, run the next command:<\/p>\n\n\n\n That\u2019s it! Apache is now installed. To test your installation, change to the \/var\/www\/html<\/span> directory and list the files:<\/p>\n\n\n\n You should have an index.html<\/em> file in that folder. To open that page in your browser, you need to know the Raspberry Pi IP address. Use:<\/p>\n\n\n\n In my case, the Raspberry Pi IP address is 192.168.1.86. If you open your RPi IP address in any browser in your local network, a similar web page should load (http:\/\/192.168.1.86<\/strong>):<\/p>\n\n\n PHP is a server side scripting language. PHP (H<\/strong>ypertext P<\/strong>rep<\/strong>rocessor) is used to develop dynamic web applications. A PHP file contains <?php \u2026 ?><\/span> tags and ends with the extension .PHP<\/span>.<\/p>\n\n\n\n To install PHP on Raspberry Pi, run:<\/p>\n\n\n\n You can remove the index.html<\/em> and create a PHP script to test the installation:<\/p>\n\n\n\n In your index.php<\/em> file add the following code to echo the \u201chello world<\/strong>\u201d message:<\/p>\n\n\n\n To save your file: press Ctrl+X<\/strong>, followed by y<\/strong>, and press Enter <\/strong>to exit.<\/p>\n\n\n\n Finally, restart Apache2:<\/p>\n\n\n\n To test if Apache2 is serving .php<\/em> files, open the Raspberry Pi IP address and it should display the \u201chello world<\/strong>\u201d message from the index.php<\/em> script created earlier.<\/p>\n\n\n If everything is working, you can remove index.php<\/em><\/span> file from the \/var\/www\/html<\/span> directory:<\/p>\n\n\n\n Now, create a file called get_ESP_data.php<\/span>.<\/p>\n\n\n\n Enter the following PHP code:<\/p>\n\n\n\n Press Ctrl+X<\/strong>, followed by y<\/strong>, and press Enter <\/strong>to exit and save the file. This previous script reads the updated file (new code uploaded to the same directory that those files are located) and echo’s it back in response to a request made by the ESP when it calls the check_for_updates<\/span> function as we’ll see later on.<\/p>\n\n\n\n Create another file called delete_ESP_data.php<\/span>.<\/p>\n\n\n\n Enter the following PHP code:<\/p>\n\n\n\n Press Ctrl+X<\/strong>, followed by y<\/strong>, and press Enter <\/strong>to exit and save the file. This file will delete the update file from the PHP server after the ESP has downloaded it.<\/p>\n\n\n\n That’s it. The PHP server is created and able to echo a new file to the ESP and delete it in response to different requests.<\/p>\n\n\n\n Before proceeding make sure you burned your boards with MicroPython firmware.<\/p>\n\n\n\n To test the PHP server and integrate it with the ESP boards to make OTA updates, we’ll show you a simple example. This example needs three files: boot.py<\/em><\/span>, main.py<\/em><\/span>, and program.py<\/em><\/span>.<\/p>\n\n\n\n Using your favorite MicroPython IDE, create a file called boot.py<\/em><\/span> with the following content and upload it to your board.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n This file imports the required libraries for network connection. It also creates a boolean variable called OTA<\/span> that indicates whether it’s time to perform an OTA update (download the new file from the PHP server).<\/p>\n\n\n\n The ESP runs the boot.py<\/em> first. The first time it runs, there aren’t any available updates, so we set the OTA<\/span> variable to 0.<\/p>\n\n\n\n Create a file called main.py<\/em><\/span> with the following content and upload it to your board. You need to modify the file to include your own network credentials and the PHP server URL for the updates.<\/p>\n\n\nProject Overview<\/h2>\n\n\n\n
![\"ESP32](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2022\/03\/micropython-OTA-updates-how-it-works-ESP32-ESP8266.png?resize=750%2C496&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n
\n
\n
Prerequisites<\/h2>\n\n\n\n
1) MicroPython Programming<\/h3>\n\n\n
![\"MicroPython](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2018\/10\/Micropython-logo.svg-Copy.png?resize=250%2C254&quality=100&strip=all&ssl=1\"){kind=logo}
<\/figure><\/div>\n\n\n\n
2) PHP Server<\/h3>\n\n\n
![\"PHP](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2022\/03\/PHP-logo.svg_.png?resize=150%2C81&quality=100&strip=all&ssl=1\"){kind=logo}
<\/figure><\/div>\n\n\nLocal PHP Server<\/h4>\n\n\n\n
\n
Cloud PHP Server<\/h4>\n\n\n\n
PART 1 – Creating the PHP Server<\/h2>\n\n\n\n
Updating and Upgrading<\/h3>\n\n\n\n
pi@raspberrypi:~ $ sudo apt update && sudo apt upgrade -y<\/strong><\/code><\/pre>\n\n\n\npi@raspberrypi:~ $ sudo chown pi:pi*<\/strong><\/code><\/pre>\n\n\n\nInstalling Apache2<\/h3>\n\n\n\n
pi@raspberrypi:~ $ sudo apt install apache2 -y<\/strong><\/code><\/pre>\n\n\n\npi@raspberrypi:~ $ cd \/var\/www\/html<\/strong>\npi@raspberrypi:\/var\/www\/html $ ls -al<\/strong>\nindex.html<\/code><\/pre>\n\n\n\npi@raspberrypi:\/var\/www\/html $ hostname -I<\/strong><\/code><\/pre>\n\n\n![\"Raspberry](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/09\/1-Raspberry-Pi-change-directory-RPi-IP-Address.png?resize=501%2C178&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"Raspberry](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/09\/2-Raspberry-Pi-Apache2-Installed.png?resize=840%2C565&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nInstalling PHP on Raspberry Pi<\/h3>\n\n\n\n
pi@raspberrypi:\/var\/www\/html $ sudo apt install php -y<\/strong><\/code><\/pre>\n\n\n\npi@raspberrypi:\/var\/www\/html $ sudo rm index.html<\/strong>\npi@raspberrypi:\/var\/www\/html $ sudo nano index.php<\/strong><\/code><\/pre>\n\n\n\n<?php echo \"hello world\"; ?><\/code><\/pre>\n\n\n![\"Raspberry](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/09\/3-Raspberry-Pi-Create-PHP-Test-File-Hello-World.png?resize=597%2C354&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\npi@raspberrypi:\/var\/www\/html $ sudo service apache2 restart<\/strong><\/code><\/pre>\n\n\n\n![\"Raspberry](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/09\/4-Raspberry-Pi-test-PHP-File-Hello-World-message-web-browser.png?resize=557%2C233&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\npi@raspberrypi:\/var\/www\/html $ sudo rm index.php<\/strong><\/code><\/pre>\n\n\n\nCreating the php server – get_ESP_data.php<\/h3>\n\n\n\n
pi@raspberrypi: sudo nano get_ESP_data.php<\/strong><\/code><\/pre>\n\n\n\n<?php\n $file = $_GET['file'];\n $dir = getcwd();\n $file = $dir.'\/'.$file;\n $myfile = fopen($file, \"r\") or die(\"FAIL\");\n echo file_get_contents($file);\n fclose($myfile);\n?><\/code><\/pre>\n\n\n\nCreating the php server – delete_ESP_data.php<\/h3>\n\n\n\n
pi@raspberrypi: sudo nano delete_ESP_data.php<\/strong><\/code><\/pre>\n\n\n\n<?php\n $file = $_GET['file'];\n $dir = getcwd();\n $file = $dir.'\/'.$file;\n unlink($file);\n?><\/code><\/pre>\n\n\n\nPART 2 – Programming the ESP32\/ESP8266<\/h2>\n\n\n\n
boot.py<\/h3>\n\n\n\n
# OTA updater for ESP32 running Micropython by David Flory\r\n# Tutorial: https:\/\/randomnerdtutorials.com\/esp32-esp8266-micropython-ota-updates\/\r\n\r\ntry:\r\n import usocket as socket\r\nexcept:\r\n import socket\r\n\r\ntry:\r\n import urequests as requests\r\nexcept:\r\n import requests\r\nimport os \r\nimport sys\r\nimport esp\r\nesp.osdebug(None)\r\nimport gc\r\ngc.collect()\r\nfrom utime import sleep\r\nfrom utime import sleep_ms\r\nimport network\r\n\r\nOTA = 0<\/code><\/pre>\n\tOTA = 0<\/code><\/pre>\n\n\n\nmain.py<\/h3>\n\n\n\n
\r\n"""\r\nOTA updater for ESP32 running Micropython by David Flory.\r\nTutorial: https:\/\/randomnerdtutorials.com\/esp32-esp8266-micropython-ota-updates\/\r\n\r\nThis is a simple way to run a python program on the ESP32 and download updates or a different program\r\nto run from an HTTP server, either from the web or your local network.\r\n\r\nPut all the imports needed for internet in boot, plus a global variable called OTA\r\nThe main file creates the internet connection then runs whatever program is required. I call the program 'program.py'\r\n\r\nprogram.py is the main program, and can be whatever you want. The only requisite for this to work with OTA is that\r\nit must be imported into the module 'main' and it must check periodically for updates.\r\nThe Program should have a function that can be called by 'main' to start it.\r\n\r\nWe can overwrite program.py while it is running, because it has been imported on boot into the namespace of 'main'.\r\nAll that is required is a reboot after a new Program.py is downloaded. In this case the deep sleep function will reboot the ESP32.\r\n\r\n"""\r\n#When prog.py finishes, if OTA = True, main downloads it and overwrites program.py, then effectively reboots.\r\n#If OTA is false main just exits.\r\n\r\n#this is the program to be executed. Note we do not use the '.py' extension.\r\nimport program\r\n\r\nimport machine #needed for the deep sleep function\r\n\r\n#URLs for the updates\r\n#replace with your PHP server URL or local IP address (Raspberry Pi IP Address)\r\nupd_url="http:\/\/192.168.1.XXX\/get_ESP_data.php?file=program.py"\r\n\r\n\r\n#change your wifi credentials here. \r\nssid = 'REPLACE_WITH_YOUR_SSID'\r\npassword = 'REPLACE_WITH_YOUR_PASSWORD'\r\n\r\nprint('OTA is ' + str(OTA))#debug\r\n\r\n#here we set up the network connection\r\nstation = network.WLAN(network.STA_IF)\r\nstation.active(False)\r\nstation.active(True)\r\n#station.config(reconnects = 5)\r\n\r\nstation.connect(ssid,password)\r\n\r\nwhile station.isconnected() == False:\r\n pass\r\n\r\n#print board local IP address\r\nprint(station.ifconfig())\r\n\r\nif OTA == 0:\r\n print('starting program')\r\n OTA = program.mainprog(OTA)\r\n \r\n#mainprog() is the starting function for my program. OTA is set to 0 on boot so the first time this code\r\n#is run, it sets up the network connection and then runs the program.\r\n#The following code only runs when program.py exits with OTA = 1\r\n\r\nif OTA == 1:\r\n print('Downloading update')\r\n #download the update and overwrite program.py\r\n response = requests.get(upd_url)\r\n x = response.text.find("FAIL")\r\n if x > 15:\r\n #download twice and compare for security\r\n x = response.text\r\n response = requests.get(upd_url)\r\n if response.text == x:\r\n f = open("program.py","w")\r\n f.write(response.text)\r\n f.flush()\r\n f.close\r\n \r\n #soft reboot \r\n print('reboot now')\r\n machine.deepsleep(5000)\r\n<\/code><\/pre>\n\t