The SOMO-II is an MP3 player, which can be instructed to play an mp3 file with commands over a serial line. This project contains an Arduino Pro Mini to translate pushbutton commands  into SOMO-II commands. Pushbuttons are used to "play the next message", "play the last message again", and "play the previous message again". A rotary encoder allows for volume control. After pushing the rotary encoder the brightness of the display is increased and the user can switch between routes and navigate faster within a route. After an adustable time (5 to 120 seconds, 10 seconds by default) the display returns to the lower brightness level and the rotary encoder function is volume control again. After powerup with the rotary encoder pushed more settings are available: low and high brighness and contrast of display and the timer setting.
The routedescription(s) must be pre-recorded on a micro SD card.
The design only involves through hole components