Reads data from LYWSD03MMC Xiaomi Mijia temperature sensor and stores it in a SQLite database.

mijia_temperature.php

<?php
/**
 * Reads data from LYWSD03MMC Xiaomi Mijia temperature sensor
 * and stores it in a SQLite database.
 *
 * @author BohwaZ <https://bohwaz.net/>
 * @see https://github.com/davi-domo/Xiaomi-Mijia-LYWSD03MMC-/blob/main/mijia_bd/MIJIA_MULTI_BD.sh
 * @see https://smhosy.blogspot.com/2021/01/quelle-temperature-et-hydrometrie-dans.html
 * @see https://www.fanjoe.be/?p=3911
 *
 * Usage: php script.php MAC_ADDRESS NAME SQLITE_DB_PATH MAX_READS
 *
 * MAC_ADDRESS = MAC address of the Bluetooth device (use 'hcitool lescan')
 * NAME = Name of this sensor (in case you have multiple sensors)
 * SQLITE_DB_PATH = Path to SQLite database, eg. /tmp/temperatures.sqlite
 * MAX_READS = Stop the script after X notifications read from the sensor
 * (1 = will stop immediately)
 */

if ($argc != 5) {
	printf("Usage: %s MAC_ADDRESS NAME SQLITE_DB_PATH MAX_READS\n", $argv[0]);
	exit;
}

list(, $mac_address, $name, $db_path, $max_reads) = $argv;

$db = new \SQLite3($db_path);

$db->exec('CREATE TABLE IF NOT EXISTS stats (
	id INTEGER PRIMARY KEY,
	datetime TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
	mac_address TEXT,
	name TEXT,
	temperature REAL, -- Temperature in °C: 22,98
	humidity INTEGER, -- Humidity in %: 63%
	battery INTEGER -- Battery level in %
);');

$cmd = sprintf('gatttool -b %s --char-write-req --handle="0x0038" --value="0100" --listen', $mac_address);

print("Waiting for sensor");

$process = proc_open($cmd, [1 => ['pipe', 'w'], 2 => ['pipe', 'w']], $pipes);
stream_set_blocking($pipes[1], false);
stream_set_blocking($pipes[2], false);

$data = null;
$reads = 0;

while (!$data) {
	$line = fgets($pipes[1], 1024);
	$error = fgets($pipes[2], 1024);

	if ($error) {
		fclose($pipes[1]);
		fclose($pipes[2]);
		echo "\nFailed! " . $error . PHP_EOL;
		proc_terminate($process);
		exit(proc_close($process));
	}

	if (preg_match('/Notification handle.*value: (.*)/', trim($line), $match)) {
		store_data($match[1]);

		if (++$reads >= $max_reads) {
			break;
		}
	}

	sleep(1);
	echo ".";
}

fclose($pipes[1]);
fclose($pipes[2]);

proc_terminate($process);
proc_close($process);

function store_data(string $data): void
{
	global $db, $mac_address, $name;
	$result = explode(' ', $data);

	$temperature = hexdec($result[1] . $result[0]) / 100;
	$humidity = hexdec($result[2]);
	$battery = hexdec($result[4] . $result[3]) / 1000;

	// https://www.fanjoe.be/?p=3911
	// Ma conclusion est que la plage de 0 à 100% de la batterie correspond à 2,1v à 3v
	$battery = (($battery - 2.1) / 0.9) * 100;

	printf("\ntemp=%f°C, humidity=%d%%, battery=%d%%", $temperature, $humidity, $battery);

	$st = $db->prepare('INSERT INTO stats (mac_address, name, temperature, humidity, battery) VALUES (?, ?, ?, ?, ?);');
	$st->bindValue(1, strtoupper($mac_address));
	$st->bindValue(2, $name);
	$st->bindValue(3, (float) $temperature);
	$st->bindValue(4, (int) $humidity);
	$st->bindValue(5, (int) $battery);
	$st->execute();
}

$db->close();

echo "\n";