BMC048 - Single Rhythm PCB & PIC | Barton Musical Circuits

I. Features

A.How it works

This module is based on BMC27. Random Rhythms. Like that module, it is microcontroller based and uses a pseudo-random number generator to create rhythmic patterns. While that module provided four channels of random rhythm generation, this only provides one or two (depending on the mode selected), but adds the ability to save a randomly generated beat to EEPROM memory so it can be loaded later, even after powering the module off. The module is compatible with +/-12V or +/-15V systems without needing to substitute any parts.

B.Controls/Inputs/Outputs

CONTROLS

1.Length – This knob controls the length of the pattern. Length is measured by incoming clock beats. When the knob is fully counter clockwise the pattern will be 2 clock inputs long, and when fully clockwise it will be 256 clock beats long.

2.Divide – This knob controls the way in which the clock input is divided or multiplied when outputting beats. Adjusting this control will not affect length. When the knob is fully counter clockwise it will multiply the beat by 4 and when fully clockwise it will divide by 64.

3.New – This button will generate a new rhythmic pattern.

4.Reset – This button will reset the rhythmic pattern, so that on the next clock input it will return to the first beat.

5.Save – This button saves the current rhythm to the selected bank.

6.Load – This button loads the rhythm saved to the current bank.

7.Bank Select – This toggle selects which bank the save/load buttons will use. There are three banks available, depending on if the toggle is up, down or center.

INPUTS

1.Clock – An LFO or clock source should be input to this jack to control the tempo of the rhythms.

2.New – This input is in parallel with the New button, a gate signal on this input will create a new pattern.

3.Reset – Like the New input, it works parallel to the Reset button.

OUTPUTS

1.Gate – In normal mode, this outputs the gate. Both outputs alternate between 0 and +5V. It will turn on at the start of an on beat and stay on until an off beat.

2.Trigger – In normal mode, this outputs the trigger. It will turn on at the start of an on beat and stays on for about 1ms.

C. Alternate Modes/Mode Selection

There are two alternate modes to this module, “Double Trigger” and “Double Gate.” In each mode, the two outputs will each output a separate rhythm while still sharing the same controls for length, division and save/load. Modes can be changed on power up, and your selection will be saved to the microcontrollers memory, so next time you power up your rack, it will be in the mode you set it to. Here are instructions for selecting a mode

1.Power off your modular system.

2.Turn the Division and Length knobs fully clockwise

3.Use the bank select toggle to select a mode. The toggle's selection is like this: UP = Normal Mode CENTER = Double Gates DOWN = Double triggers

4.Hold down the reset button as you power on your modular system.

5.That's it!