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MIDI to 10 Outputs



This unit utilizes MIDI Note ON/OFF data to  control  LEDS, Relays, Transistors, Triacs, etc. to switch Lights, Motors, etc. when combined with suitable output circuitry. 





MIDI Notes to 10 Outputs


PRICE:  €50.00









The MIDI to 10 Outputs unit utilizes:

  • An Arduino including a suitable pre-programmed Atmega microcontroller,
  • A 2.1mm power socket, and associated LED, 
  • Select MIDI channel at power-on, in programme mode, 
  • Select MIDI start-note at power-on, in programme mode, 
  • A 4-way DIP switch, which selects the MIDI channel at power-on, shown in table 1
  • A 150mm wired MIDI 5-pin DIN input socket,
  • A 150mm wired MIDI 5-pin DIN output socket,
  • Outputs (0-9) are programmable from first  MIDI note on/off command, 
  • The circuit schematic is available,
  • MIDI IN/OUT circuit schematic,
  • A Programme Mode LED



The MIDI to 10 outputs also requires:


Circuit Schematic:

A circuit schematic of the MIDI to 10 Outputs unit shows the output and Programme switch connections. Note that the Arduino is a multi-function microcontroller board and the Analog Inputs A0 to A5 are also Digital Outputs D14 to D19. The 10 output Pins are Analog Pins A0 to A5 and Digital Pins D8 to D11.












     *Click to Enlarge*

The MIDI IN and OUT connectors use  5-Pin 180 degree DIN sockets. Note that the MIDI IN/OUT wiring is polarised and the correct pins should be used.




Output Current Drive:

You can get a maximum of 40 mA (milliamps) current from each output separately. But the maximum combined rating when several pins are active at the same time  is 200 mA for all pins. However it is probably best not to run the outputs at their maximum rating.


Normal Mode:

The unit detects the incoming MIDI data and if the MIDI channel corresponds to the correct MIDI channel setting, when a corresponding Note-on is detected, (to the pre-set note-on  data), the corresponding output is switched on (+5 Volts) and stays on until the corresponding note-off is detected and the output is switched off (0 Volts). This allows each output to operate independently. 


Programme Mode:

At power-up, when switching on the unit, if the programme switch is pressed and held on, then the unit will enter programme mode, and the programme LED is lit. 


Now the first  Note-on command from a MIDI keyboard or sequencer is detected and stored in the EEPROM. This note is the first of 10 consecutive note values, associated with outputs 1 to 10. Also the MIDI channel, which the Note-On command is transmitted on, is also stored in the EEPROM.


After the Note-on is detected the unit goes into normal operating mode, and the programme LED is off. So the 16 outputs are programmed to operate consecutively from only the first Note-on command detected. 


Programming the unit only has to be done once and the MIDI start-note and channel are stored internally in the EEPROM and the unit will continue to operate in this mode, (even when power is removed and re-applied), until the unit is re-programmed. 




The MIDI to 10 outputs unit can be operated live in real time from a MIDI keyboard or from a hardware/software sequencer with pre-programmed MIDI Note on/off data. The outputs can be used, via suitable interface circuitry, to switch electrical devices, such as lights, motors, pumps etc., in time with the music. Use the outputs to control and synchronize auxiliary circuitry. This provides a direct interface to the world of analogue electronics. 



MIDI Specification: 

The outputs are switched ON via MIDI 'Note-On' commands and OFF by MIDI 'Note-off' commands. These MIDI commands are all channel (1-16) dependent. Also, the outputs will switch off if  a correct MIDI Note On with a velocity of 00  is received. The unit also works in MIDI Running Status mode.



The MIDI to 10 output units can be combined/expanded by connecting the MIDI OUT of one unit to the MIDI IN of the following unit. Thus producing 20, 30, 40 etc. outputs.




DIP Switch Selections



4 3 2 1
on on on on 1
on on on off 2
on  on  off on 3
on on off off 4
on off on on 5
on off on off 6
on off off on 7
on off off off 8
off on on on 9
off on on off 10
off on  off on 11
off on off off 12
off off on on 13
off off on off 14
off off off on 15
off off off off 16

Table 1 MIDI Channel



Power Supply:

The  Arduino can be powered via the USB connection or with an external power supply. The power source is selected automatically.


External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. The adapter can be connected by plugging a 2.1mm center-positive plug into the board's power jack. Leads from a battery can be inserted in the Gnd and Vin pin headers of the POWER connector. A low dropout regulator provides improved energy efficiency.


The board can operate on an external supply of 7 to 20 volts. If supplied with less than 7V, however, the 5V pin may supply less than five volts and the board may be unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts.


Note that with the Arduino Duemilanove or Mega the power input selection (USB/EXT.) is automatically selected.