Hirlostek

Self powered Bright Noise generator

This cable expands every synth without a noise generator but an external audio input and a 5V source at the tip of a socket (e.g. an expression pedal input) and gives you digital noise.

Initially the cable has been developed as an expansion for the Moog products Little Phatty and Minitaur but it works also with other synths etc.

The Hirlostek needs to be provided with a 5V voltage, for instance at the tip of a expression pedal socket. A circuit inside of the bigger plug generates a bright digital noise you can use as audio or modulation source. The narrower plug carries the noise signal and is to be connected either with an audio input or a CV input. Hand made, military quality due to good Neutrik jacks.

Source Code

 title  "White Noise Generator"
;
;  SOFT Bretelle Bruit blanc (ULTRA RAPIDE CANARI - )
;  Original Tom Wiltshire for Elecric Druid, March 2008
;  adapté et modifié par Hubert LEON - ACTRIS pour cible 12F508 	
;
;  Hardware Notes:
;   PIC12F508 running at 4 MHz using internal clock


	list      p=12f508           ; list directive to define processor
	#include <p12f508.inc>        ; processor specific variable definitions

	errorlevel  -302              ; suppress message 302 from list file

	__CONFIG   _CP_OFF & _MCLRE_OFF & _WDT_OFF & _IntRC_OSC


;------------------------------
;	Variables
;------------------------------

 CBLOCK 0x0010

	; LFSR 1, a 31-bit register
	LFSR1_1
	LFSR1_2
	LFSR1_3
	LFSR1_4
	; LFSR 2, a 23-bit register
	LFSR2_1
	LFSR2_2
	LFSR2_3
	; Temporary storage
	TEMP
 ENDC

;-------------------------------------
;	DEFINE STATEMENTS
;-------------------------------------

; Useful bit definitions for clarity	
#define ZEROBIT		STATUS,Z	; Zero Flag
#define CARRY		STATUS,C	; Carry Flag
#define BORROW		STATUS,C	; Borrow is the same as Carry


;----------------------------------------------------------------------
; Begin Executable Code Segment
;----------------------------------------------------------------------
	org     0x000		; processor reset vector
    
	movlw	b'00101111'		; GP4 Output, all others unused inputs
	TRIS	GPIO   

	clrf	GPIO


	; Set up initial values of the registers
	movlw	0x45
	movwf	LFSR1_1
	movlw	0x57
	movwf	LFSR1_2
	movlw	0x9F
	movwf	LFSR1_3
	movlw	0xF2
	movwf	LFSR1_4
	movlw	0xD7
	movwf	LFSR2_1
	movlw	0xC8
	movwf	LFSR2_2
	movlw	0x79
	movwf	LFSR2_3





MainLoop:
;----------------------------------------------------

	swapf	LFSR1_4, W	; Get bit 28
	movwf	TEMP
	rlf		LFSR1_4, W	; Get bit 31
	xorwf	TEMP, F
	; Shift the XORd bit into carry
	rlf		TEMP, F
	; Shift the register
	rlf		LFSR1_1, F
	rlf		LFSR1_2, F
	rlf		LFSR1_3, F
	rlf		LFSR1_4, F
	; Output the noise bit
	movf	LFSR1_1, W
	movwf	GPIO


;----------------------------------------------------
	
	rrf		LFSR2_3, W	; Get bit 19
	movwf	TEMP
	rrf		TEMP, F
	swapf	LFSR2_3, W	; Get bit 21
	xorwf	TEMP, F
	; Shift the XORd bit into carry
	rrf		TEMP, F
	; Shift the register
	rlf		LFSR2_1, F
	rlf		LFSR2_2, F
	rlf		LFSR2_3, F
	; Output the noise bit
	movf	LFSR2_1, W
	movwf	GPIO

	goto	MainLoop

	end