PHP in the World of Microcontrollers: An Unexpected Duo for Embedded

Why PHP in the World of Hardware? Breaking Stereotypes

When you hear "embedded development," the first things that come to mind are C, assembly, maybe MicroPython. PHP? A web language that runs on a server and generates HTML. What does it have to do with microcontrollers, sensors, and firmware?

Actually, it has a direct connection. PHP has long outgrown the "scripting language for forums" label. Modern interpreters (starting with PHP 7+) can run on ARM architectures, and there are several interesting solutions for embedded environments. This article is not an academic report, but a practical guide on how PHP can become your assistant in the world of embedded systems. We'll analyze real-world cases, write code, and see where it's truly convenient.

When is PHP a Reasonable Choice for Embedded?

Don't confuse a "microcontroller with 2 KB of RAM" with a "single-board computer running Linux." PHP won't run on an ATmega328P (Arduino Uno) — for that, you need C/C++. But if your device runs on:

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• ESP32 (ESP-IDF or esp8266 with RTOS);
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• Raspberry Pi (or similar boards on Allwinner, Rockchip);
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• OpenWrt routers with MIPS/ARM;
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• Industrial controllers on Linux.
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…then PHP can be the ideal "glue" between your hardware and the outside world. Especially if you need to quickly create a web interface to control the device, parse data from sensors, or send it to the cloud.

How to Run PHP on a Microcontroller? Real Options

There are two main approaches, and we'll look at both with code examples.

1. PHP on ESP32 using ESP-IDF (Native PHP)

Yes, there are projects that port the PHP interpreter to bare-metal microcontrollers. The most famous one is PHP for ESP32 (an experimental fork). It's a stripped-down version of the language without multithreading, but with basic syntax, arrays, strings, and GPIO.

Example: Blinking an LED with PHP on ESP32

<?php\n// Include the library for working with pins\nrequire "gpio.php";\n\n// Configure GPIO2 (built-in LED on many ESP32 boards) as output\n$pin = new GPIO(2, GPIO::OUTPUT);\n\nwhile (true) {\n    $pin->write(GPIO::HIGH);\n    delay(1000); // 1 second\n    $pin->write(GPIO::LOW);\n    delay(1000);\n}\n?>

The code looks familiar, right? This is not a joke — such a project exists in GitHub repositories. Of course, performance is lower than in C, but for prototyping, it's great.

2. PHP as a "Server Layer" on Linux-Compatible SBCs

This is the most practical scenario. You take a Raspberry Pi or Orange Pi, install standard PHP (e.g., php8.3-cli), and use it for:

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• Reading data from GPIO via gpiod or wiringPi;
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• Working with I2C/SPI sensors (temperature, humidity, pressure);
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• Creating a REST API to control the device.
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Example: Reading temperature from a DHT22 via PHP on Raspberry Pi

<?php\n// Use a shell command to read data (via pigpio)\n$output = shell_exec('pigs in 17'); // GPIO17\nif ($output === false) {\n    die("Error reading sensor");\n}\n\n// Parse and output\n$data = explode(" ", trim($output));\n$humidity = $data[0] / 10;\n$temperature = $data[1] / 10;\n\necho "Temperature: {$temperature}°C, Humidity: {$humidity}%\\n";\n?>

You can go further and wrap this in a web server:

<?php\n// api.php - simple REST endpoint\nheader('Content-Type: application/json');\n\n$temperature = readSensor(); // your function\necho json_encode([\n    'status' => 'ok',\n    'temp' => $temperature,\n    'timestamp' => time()\n]);\n?>

Run it: php -S 0.0.0.0:8080 api.php — and you have a ready IoT gateway!

Practical Use Cases: Where PHP Wins