OLIMEX© 2015
MOD-RGB firmware note
DMX MODE
Requires RS-485 interface (MOD-RS485 and MOD-RS485-ISO are tested and working
successfully).
To enter DMX512 mode:
Turn off/power down MOD-RGB then close DMX_EN and turn on/power up MOD-RGB. The
other jumper UPWR_E shoud be closed if the device board we interface with needs to be powered
via the UEXT. If we use MOD-RS485 we also close UPWR_E and then we power cycle the board.
In the beginning the board has no address. To acquire one we transmit data (different than 0) to a
channel. For instance we transmit the value N to RED channel. Then GREEN would be N+1 and
N+2 would be BLUE. If we want to change the addresses again we open and then close the
DMX_EN jumper.
I2C MODE
To enter audio-in/I2C mode (default):
Power the board up with jumper DMX_EN being open. In this mode we can connect audio stream
via the audio jack and the LEDs (or the LED strips) should start blinking according to the music.
Note the board works with frequencies in the (100-150)Hz range – if you listen to music with no
proper bass the demo won't work properly!
This audio mode would remain active until you send a command via the I2C line (via the UEXT).
The commands available are:
1.
0x01
– Enable LED PWM (start);
2.
0x02
– Disable LED PWM (stop);
3.
0x03
– Entering RGB colors in
0
to
255
(
3
parameters);
4.
0x14
– Command to receive the input signal from the audio-in connector. The ADC is
configured for 150Hz.
5.
0x15
– Command to disable the input signal from the audio-in. R, G and B are set to
0
.
6.
0x20
– Read the board ID number. By default
0x64
.
7.
0xF0
– Assign new address for the board. Before sending the command DMX_EN jumper must
be closed. After that, make sure that the jumper is opened again, to avoid accidentally changing the
address
Initially the default I2C address is
0x20
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