Build your own MIDI circuits.

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MIDI & Music
MIDI and Music Information
MIDI to 62 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. 


The unit responds to the default range of 62 MIDI notes from 36(C2) to 97(C#7). However any consecutive 62 note MIDI range can be pre-programmed into the unit on request. The 62 outputs, on the Arduino Mega, start at Digital Pin D8 and continue consecutively to pin D69. (Note that Analog In Pins A0 to A15 are configured as digital outputs D54 to D69, respectively, as shown in Output Pin Mapping information.) 





midi_in_out_mega.jpg (283771 bytes)


MIDI Notes to 62 Outputs


PRICE:  €70.00







The MIDI to 62 Outputs unit utilizes:

  • An assembled Arduino MEGA unit including a suitable pre-programmed Atmega 1280,
  • A 2.1mm power socket, and associated Power LED, 
  • A USB socket for power selection,
  • Select MIDI channel via a 4-way DIP switch,  
  • A MIDI 5-pin DIN input socket,
  • A MIDI 5-pin DIN output socket,
  • 62 off 0.1" pin-terminal outputs,
  • The consecutive 62 outputs (0-61) can be pre-programmed to any MIDI start note,
  • The circuit schematic is available



The MIDI to 62 outputs also requires:



The unit is pre-assembled, programmed and tested.


Circuit Schematic:

A circuit schematic of the MIDI IN/OUT board shows the Input/Output connections. Arduino Pin D0/RX is connected to the output of the Opto-coupler whose input is connected to the MIDI IN socket. Arduino Pin D1/TX is connected to the MIDI OUT socket via resistor R5. Arduino Pins D2 and D3 provide +5 Volt and 0 Volt(GND) but they need to be set correctly in the software. Arduino Pins D4, D5, D6 and D7 are connected to the 4-way DIL switch, which can be used to select the MIDI Channel (1 to 16).


So 8 Pins (D0 to D7) are used  when the MIDI IN/OUT board is plugged into the Arduino. All other pins are still accessible. 

The outputs, on the Arduino Mega, start at Digital Pin D8 and continue consecutively to pin D69. (Note that Analog In Pins A0 to A15 are configured as digital outputs D54 to D69, respectively, as shown in the Arduino Mega pin mapping information.) Also available is the Arduino Mega board and pin layout.



MIDI Wiring:

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. For example, if driving LEDS directly via a series resistor,then high effeciency LEDS should be used to reduce the current required.


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. 



The MIDI to 62 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. The MIDI channel (1 to 16) is selected by the 4-way DIP switch, shown in Table 1.  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.


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



The MIDI to 62 output units can be combined/expanded by connecting the MIDI OUT of one unit to the MIDI IN of the following unit. Thus producing 124 outputs.


Power Supply:

The  Arduino MEGA can be powered via the USB connection or with an external power supply. The power source is selected automatically. The Arduino MEGA draws about 65 mA on standby.


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.