hi,
after some failed calibration attempts i decided to completely finish the unit and put it in its housing to eliminate possible error sources. Well that was quite a success since the button noise, constant gate voltage and the strange rebooting are gone now, ye-haw ;D (must have fed some voltage to the ground with those alligator clips 
or something like that)
But one problem remains:
I’ve set the all cv channels to 8/8 bit, see a part of the code here (but i assume it`s correct):
;
; use PORTA and PORTE (J5 of the core module) for 8 additional gate outputs
#define ENABLE_J5 1
;
;
; define the AOUT interface which is used here:
; 1: one MBHP_AOUT module
; 2: up to 4 (chained) MBHP_AOUT_LC modules
; all other values invalid!
#define DEFAULT_AOUT_INTERFACE 2
;
;
; only relevant if one or more AOUT_LC modules are used:
; define the resolution configuration here
; 1: first channel 12bit, second channel 4bit
; 2: first channel 8bit, second channel 8bit
; all other values invalid!
#define DEFAULT_AOUT_LC_1_RESOLUTION 2 ; 1st AOUT_LC module
#define DEFAULT_AOUT_LC_2_RESOLUTION 2 ; 2nd AOUT_LC module
#define DEFAULT_AOUT_LC_3_RESOLUTION 2 ; 3rd AOUT_LC module
#define DEFAULT_AOUT_LC_4_RESOLUTION 2 ; 4th AOUT_LC module
;
;
; define the pin which should be used as external clock output here
; DEFAULT_EXT_CLK_LAT can be LATC (Pin 0, 1, 2, 4, 5) or LATD (Pin 4)
; The external pin is disabled with DEFAULT_EXT_CLK_LAT == 0
#define DEFAULT_EXT_CLK_LAT LATD
#define DEFAULT_EXT_CLK_PIN 4
;
; desired pulsewidth of clock output in pieces of 500 uS
; 0 -> 500 uS
; 1 -> 1 mS
; 2 -> 1.5 mS
; etc…
#define DEFAULT_EXT_CLK_PULSEWIDTH 1
but still i get some strange behavior on every second cv channel (e.g. 2,4,6,8):
While calibrating, the 1V setting cannot be reached - maximum possible is about 0,6 to 0,8 Volts - while the other voltages are ok (min, max, 2,4,8,)
When connecting a synth then, the octaves are like - it’s hard to describe - cut in half. the 4 lowest notes of every octave are played twice, so when playing the complete octave, the notes are like this: c1, c1#, d1, d1#, c1, c1#, d1, d1# an then it continues with the same notes one octave higher.
I’ve tried with 8/8 V/OCT, Hz/V and 12/4 Hz/V with several analog synths but it`s always about the same, so the problem must source somewhere else.
And again, CV Channels 1, 3, 5 and 7 work perfect, without any trouble.
Any suggestions?
Thanks again & best regards,
Max
p.s.: any recommendations on a simple s&h ciruit to eliminate that zipper noise? i assume a part of the SHX8 would do, but as mentioned, my electronic knowledge is very limited ::) :-\
