diff --git a/backend/bin.mjs b/backend/bin.mjs
index 51a35ca..2e654e8 100755
--- a/backend/bin.mjs
+++ b/backend/bin.mjs
@@ -1,9 +1,10 @@
 import minimist from 'minimist'
 import { run } from './server.mjs'
+import p from 'path'
 import createDebug from 'debug'
 import Dotenv from 'dotenv'
 
-Dotenv.config('..')
+Dotenv.config({ path: p.resolve(p.join(process.cwd(), '..', '.env')) })
 Dotenv.config()
 
 const debug = createDebug('streamer')
@@ -13,10 +14,10 @@ main().catch(onerror)
 async function main () {
   const args = minimist(process.argv.slice(2), {
     default: {
-      port: 3030,
+      port: process.env.PORT || 3030,
       host: '0.0.0.0',
-      input: 'alsa:default',
-      output: 'alsa:default',
+      input: process.env.STUDIOX_INPUT || 'alsa:hifiberry',
+      output: process.env.STUDIOX_OUTPUT || 'alsa:hifiberry',
       dev: false
     },
     alias: {
diff --git a/backend/lib/rut950.mjs b/backend/lib/rut950.mjs
index 4fb16d4..d92edc2 100644
--- a/backend/lib/rut950.mjs
+++ b/backend/lib/rut950.mjs
@@ -1,22 +1,43 @@
 import JsonRpc from 'node-jsonrpc-client'
 import esMain from 'es-main'
+import Debug from 'debug'
+const debug = Debug('rut950')
 
-const DEFAULT_OPTS = {
+const defaultOpts = () => ({
   url: process.env.RUT950_UBUS_URL || 'http://192.168.1.1/ubus',
   username: process.env.RUT950_USERNAME || 'admin',
   password: process.env.RUT950_PASSWORD || 'admin01'
-}
+})
 
 const EMPTY_SESSID = '00000000000000000000000000000000'
 
+const UBUS_STATUS_CODE = [
+   'UBUS_STATUS_OK',
+   'UBUS_STATUS_INVALID_COMMAND',
+   'UBUS_STATUS_INVALID_ARGUMENT',
+   'UBUS_STATUS_METHOD_NOT_FOUND',
+   'UBUS_STATUS_NOT_FOUND',
+   'UBUS_STATUS_NO_DATA',
+   'UBUS_STATUS_PERMISSION_DENIED',
+   'UBUS_STATUS_TIMEOUT',
+   'UBUS_STATUS_NOT_SUPPORTED',
+   'UBUS_STATUS_UNKNOWN_ERROR',
+   'UBUS_STATUS_CONNECTION_FAILED',
+   'UBUS_STATUS_NO_MEMORY',
+   'UBUS_STATUS_PARSE_ERROR',
+   'UBUS_STATUS_SYSTEM_ERROR',
+]
+
+
 export class Rut950 {
   constructor (opts = {}) {
-    opts = { ...DEFAULT_OPTS, ...opts }
+    opts = { ...defaultOpts(), ...opts }
     this.client = new JsonRpc(opts.url)
     this.opts = opts
   }
 
   async init () {
+    debug('call', 'session.login')
     const res = await this.client.call('call', [
       EMPTY_SESSID,
       'session',
@@ -29,35 +50,43 @@ export class Rut950 {
     if (!res.result || !res.result.length === 2) {
       throw new Error('received invalid response')
     }
+    debug('res', res)
     const [code, data] = res.result
+    if (code !== 0) {
+      throw new Error('Error: ' + UBUS_STATUS_CODE[code])
+    }
     this.sessid = data.ubus_rpc_session
   }
 
   async call (...params) {
     if (!this.sessid) await this.init()
+    debug('call', this.sessid, params)
     const res = await this.client.call('call', [
       this.sessid,
       ...params
     ])
-    console.log(res)
+    debug('res', res)
     if (res.error) {
       const err = new Error('RUT950 error: ' + res.error.message)
       err.code = res.error.code
       throw err
     }
     const result = res.result
-    if (!result || !result.length === 2 || result[0] !== 0) {
-      throw new Error('received invalid response')
+    if (!result) throw new Error('Received invalid response')
+    const [code, data] = result
+    if (code !== 0 || !data) {
+      throw new Error('received error: ' + UBUS_STATUS_CODE[code])
     }
     return res.result[1]
   }
 }
 
-if (esMain(import.meta)) {
+export async function demo() {
   const rut = new Rut950()
   let iwinfo = await rut.call('iwinfo', 'info', { device: 'wlan0' })
   console.log('IWINFO', iwinfo)
   //let uci = await rut.call('uci', 'show')
+  console.log('call uci show')
   let uci = await rut.call('file', 'exec', {
     command: 'uci',
     params: ['show']