Finally we clear and enable the output compare interrupt. The closest we can get to that is a prescaler of 8 and a compare match of 32. We want to set up a delay of half a bit, to get into the middle of the start bit. In the pin-change interrupt service routine we check that it’s a falling edge, and if so we set up Timer/Counter0 in CTC mode. The start of a byte causes a pin-change interrupt. MIDI is serial data at 31250bits/s so one bit time is 32 microseconds. Next we need a pinchange interrupt to handle the start bit in the MIDI serial input. PCMSK |= 1<<PCINT0 // Enable pin change on pin 0ĭigitalWrite(2,LOW) //Set initial Gate to LOW GIMSK |= 1<<PCIE // Enable pin change interrupts GIFR = 1<<PCIF // Clear pin change interrupt flag. PinMode(2, OUTPUT) // Enable Gate output pin PinMode(0, INPUT) // Enable USI input pin PinMode(1, OUTPUT) // Enable PWM output pin Enable 64 MHz PLL and use as source for Timer1 The fuses are important as we want to run the Tiny on a internal 16MHz clock. This code takes care of setting up the PWM and USI. GNU General Public License for more details.įirst we need to setup the chip. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. but WITHOUT ANY WARRANTY without even the implied warranty of These are like the Doepfer A-190 series (USB and DIN) and come in mono or Dual versions, or like the ADDAC Systems 222 with is a Quad channel version. ![]() ![]() There are Note Converters that expect to see a CV and a Gate and are scaled to convert voltages to MIDI note values. This program is distributed in the hope that it will be useful, There are two types of CV to MIDI converters out there. the Free Software Foundation, either version 3 of the License, or it under the terms of the GNU General Public License as published by This program is free software: you can redistribute it and/or modify Copyright 2019 DSP Synthesizers Sweden. (*) All in the spirit of open-source and open-hardware The ATtiny does not have a DAC so we create one using PWM.Īnd its also lacking a UART but we can use the USI component for that one. There are 2 major basic components needed for making the converter: If you know nothing about programming and just want the chip it is available preprogrammed here: Note: The chip can run off MIDI ghost-power but for the CV to play in tune the supply voltage needs to be exactly 5 volts. ![]() The gate output is 5 volt for note-on and 0 volt for Note-off. And it worked! It took several OpAmps and a charge pump for inverting the power, but it was a great learning experience and the CV12 was very resilient.The CV-out is a PWM signal and needs a lowpass filter. However, since the board had a nice modular design, I took the Port B outputs to an aux board (TOTALLY UNSUPPORTED configuration, BTW) to offset the signal by -5Vdc to accommodate the Moog Mavis. If you are using the product as it was intended, this would be a very quick job to finish. It was brilliant to have the board send a different voltage to each CV output, which made it easy for me to debug any errors in attaching the CV socket boards to the CV12. Not to worry, though, the kit was easy to assemble (less than an hour to assemble, YMMV), and the hardest part was just carefully reading the documentation to understand how it operated (since I am a newbie to modular synths). At about $30 USD, this was an obvious choice, although I was a bit nervous since I've never owned a MIDI to CV converter. (11 different modes which offer mixtures of gate, CV and clock)Īfter researching numerous MIDI to CV options, this kit seemed too good to be true. Up to 12 control voltages simultaneously or up to 11 gates AND MIDI clock. I made it to allow modular synth enthusiasts to inteface easily and cheaply between keyboards, computers and synths. The manual for the board can be found at the Midimuso site. Please note, this kit is incompatible with pre-ORAC boards which do not support chaining. Includes the manual, the schematic and a continuity diagram. Monophonic / polyphonic modes (up to 6 note poly per board)Ĭhainable: boards can be connected together to produce more outputs.ģ.5mm jack socket boards for this board are available on Ebay or from the Midimuso site: A kit containig everything needed to make a Midimuso 12 channel MIDI to CV converter.Įasy to solder with full, detailed instructions included.Ĭonverts MIDI into control voltages and gates.Īllows 1V / 0.5V / 1.2 V per octave conventions.ġ1 modes which offer a balance of pitch / velocity voltages / control voltages / gates.
0 Comments
Leave a Reply. |