diff --git a/README.md b/README.md
index 3c20084..3aa70b6 100644
--- a/README.md
+++ b/README.md
@@ -27,21 +27,28 @@ Power on the Raspberry pi and finish the installation process. Log into its cons
 - connected keyboard and monitor
 - serial port
 
+Prerequisites
+------------
+Once you are logged into the `Raspberry pi` console update your system
+> `sudo apt update`  
+`sudo apt upgrade`
+
+and install `git`. It will be used to download the `dog-trainer` 
+> `sudo apt install -y git`
+
+Recordings must be edited a little bit therefore some audio processing tool is needed. Install `ffmpeg` which will do the job  
+> `sudo apt install -y ffmpeg`
+
 How to install
 --------------
 
-Once you are logged into the `Raspberry pi` console clone the `dog-trainer` source code into your home directory
-> `git clone https://gitea.virtonline.eu/2HoursProject/dog-trainer.git --depth 1`
+Clone the `dog-trainer` source code into your home directory
+> `cd`  
+`git clone https://gitea.virtonline.eu/2HoursProject/dog-trainer.git --depth 1`
 
 Go into the newly created directory
 > `cd ~/dog-trainer`
 
-Dependencies
-------------
-
-The recordings must be edited a little bit so some audio processing tool is needed. Install `ffmpeg` which will do the job  
-> `apt install -y ffmpeg`
-
 Configuration
 -------------
 
@@ -93,4 +100,4 @@ Set volume for playback and recording
 Launch soundcard mixer
 > `alsamixer`
 
-Press F6 to select a soundcard. Find your USB sound device in the list e.g. `Jabra Speak 410 USB`. Press F4 and use up/down arrow keys to set recording volume and repeat also for the playback (F3). Press ESC fo exit.
\ No newline at end of file
+Press F6 to select a soundcard. Find your USB sound device in the list e.g. `Jabra Speak 410 USB`. Press F4 and use up/down arrow keys to set recording volume and repeat also for the playback (F3). Make sure it is not muted. Press (m) to toggle mute. Press ESC to exit.
\ No newline at end of file
diff --git a/assets/dog-trainer-schema.png b/assets/dog-trainer-schema.png
index f83a6a0..6805f8f 100644
Binary files a/assets/dog-trainer-schema.png and b/assets/dog-trainer-schema.png differ