Smopp_v2/api/controllers/TmcController.php

<?php

namespace app\controllers;

use Yii;
use app\models\entity\Tmc;

/** Created by Anton on 17.02.2020. */

class TmcController extends MainController
{
    public function beforeAction($action)
    {
        parent::beforeAction($action);
//        $key = Yii::$app->request->headers->get('uuid-key');
//        $this->checkAuth($key);
        \Yii::$app->response->format = \yii\web\Response::FORMAT_JSON;

        return true;
    }

    public function actionGive()
    {
        $userId = Yii::$app->request->post('userId');

        $tmc = Tmc::findOne(['employee' => $userId]);

        if (!$tmc) {
            $result = ['error' => 'Устройство не найдено'];
        } else {
            $result = ['success' => $tmc->characteristic];
        }


        $buf = pack("Cl", null, $result);
        echo base64_encode($buf);
    }
}