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MIDI-CV Rev 4 Module Introduction ABOUT How Setup Schematics Block, Control, Out, Power

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The MIDI-CV Module provides a means of controlling your synthesiser.

Control of a synthesiser usually requires two basic signals:-

1. a Control Voltage (CV) which usually defines the frequency of operation of the VCOs, and
2. a Gate Signal which is used to initiate or trigger the envelope shapers.

All remaining modules in the synthesiser either use one or or both of these signals or are controlled by other modules in response to one or both of the aforementioned signals.

Both of these signals can be generated by the synthesiser itself allowing the unit to `play itself'. However, the synthesiser is more often controlled by an external controller such as a keyboard or a musical instrument fitted with appropriate sensors. MIDI is a technology that allows music to be represented in a digital form and is an ideal mechanism for controlling an instrument such as a synthesiser. Information can be easily extracted from a MIDI source to provide a Control Voltage or NOTE signal and a GATE.

The MIDI Interface module used in the ASM1-Genie and ASM2-Genie is built around the Mitsubishi M16C† family of microprocessors and provides 8 control voltages for interfacing to a unit. Four of the control voltages are pre-assigned to NOTE, VELOCITY, PITCH BEND, and MODWHEEL in addition to separate GATE and TRIGGER outputs. These provide the fundamental control signals required to control the ASMx-Genie and most other analogue synthesisers.

The MIDI-CV module is a stand-alone board which can be used in a variety of MIDI applications. As such, the MIDI-CV Module can be housed in a small enclosure and requires only a +15/-15V power supply. The pcb provides connectors for MIDI-IN, MIDI-THRU and the MIDI CV signals. An RS232 socket is included on the board to allow the M16C† to be re-programmed with either future updates to the MIDI-CV Module program or the users own software application (customer applications require a suitable development platform). Flash Programming software is provided with the MIDI-CV Module and works on most variants of Microsoft Windows.

†NOTE: The M16C is a surface-mount device so the pcb is supplied, pre-programmed, with the M16C already fitted. All other components on the board are thru-hole components.

Onboard expansion options include:-

1. MIDI-OUT
2. 4x20 LCD module
3. 4x4 Keypad module
4. 8 off 8-bit analogue inputs
5. Over 16 additional I/O lines
6. EDP WASP Link support