Data Sheet

4D SYSTEMS SOMO-II
© 2014 4D SYSTEMS Page 10 of 17 www.4dsystems.com.au
SOMO
-II Embedded Audio
-Sound Module
KEY MODE
The KEY-MODE provides a stand-alone operation where a host micro is not required. With only 2 push buttons,
a 3.7V battery and a speaker, an extremely compact and low component count audio system can be
implemented.
Alternatively, KEY-MODE supports extended operation with the use of the ADKEY1 and ADKEY2 inputs, which
allow a matrix of inputs (up to 20 push buttons) to be used, each with a different value resistor connected to
either ADKEY1 or ADKEY2.
The SOMO-II Audio operations such as PLAY, PAUSE, STOP, NEXT, PREVIOUS, VOLUME etc are all available on
individual push buttons.
The following table lists each of the resistor values which are required for each of the 20 push buttons (10 push
buttons on each ADKEY1 and ADKEY2 inputs), along with an example schematic to show how the push button
and resistor is connected to the SOMO-II, in the next section.
Function
ADKEY
RESISTOR
Description
PLAY/PAUSE
1
220K ohm
Play/Pause the audio track selected (if selected) else the first
track copied on to the media (See Section 6)
STOP
1
100K ohm
Stop the current playing audio Track. If the PLAY/PAUSE button
is pressed then the audio track will start from the beginning.
NEXT/VOL+
1
51K ohm
If no track is currently playing, momentarily pressing this
button will start audio playback, playing the next track in the
order copied on to the media. If a track is playing, momentarily
pressing this button will skip to the next track in the order they
were copied on to the media (See Section 6). Holding down the
button for > 1.2 seconds will cause the Volume to Ramp Up.
Dual action for simple 2 button operation.
PREV/VOL-
1
33K ohm
If no track is currently playing, momentarily pressing this
button will start audio playback, playing the previous track in
the order copied on to the media. If a track is playing,
momentarily pressing this button will skip to the previous track
in the order they were copied on to the media (See Section 6).
Holding down the button for > 1.2 seconds will cause the
Volume to Ramp Down. Dual action for 2 button operation.
VOLUME +
1
24K ohm
Pressing this button will cause the volume to increase by 1 (0 –
30 range)
VOLUME -
1
15K ohm
Pressing this button will cause the volume to decrease by 1 (0 –
30 range)
uSD/USB
1
9.1K ohm
This button will toggle between micro-SD card and USB Flash
Drive operation. If both media are present, it will default to
micro-SD card at start-up.
SLEEP
1
6.2K ohm
This will put the SOMO-II into a sleep state, which consumes
low power. To get the SOMO-II out of sleep, you need to press
the RESET button or use the correct Serial command.
RESET
1
3K ohm
This will reset the SOMO-II module, to be in its powered-on
state, and will also awaken the SOMO-II from Sleep.
REPEAT TRACK
MODE
1
0R ohm
This will enable Repeat Track Mode, which will play the current
playing track over and over until stopped. Pressing this button
again will disable this mode. Only works if pressed when audio
is playing.