A major rewrite of the Arduino/Atari communication software was accomplished. It seems the Cassette Motor Control pin causes a spike when it switched. (You can hear it in some of the previous tracks.) BIT 7 of PORTA has been configured for output. Joystick 2 trigger can be used as BIT 7 if its ever needed.
It took a couple of weeks of software trouble shooting to figure out that the hardware was the problem. The output power from the CMC was enough to trigger the optocoupler but the power from the joystick port was not. A resister was changed and the software seemed to be working the way it should.
There still seems to be a click but is a little less noticeable.
Sorry, I wasn't going to get technical.
Music File origin: BRAND.MUS - thanks to unknown person
TRACK10.MUS - Recorded
Control Computer: 130XE
Sequencer Software: MIDI Music System by Lee Actor
Voice 1 - PAT5
Voice 2 - PAT6
Voice 3 - PAT7
Voice 4 - PAT8
MIDI out: MIDIMAX
Atari 130XE (#2)
MIDI in: Arduino Software: MONOSYN_1-Byte_Data_rC.ino
Monitor output to mixer
Software: ADSR0D.M65 (recompiled for voice settings)
(.Included READMIDC.M65) -
Loaded from ATARIMAX Cart.
Mixer: Behringer Xenyx 1202 FX
Mic One input - Atari monitor port
FX : #3 MID HALL 1
Recorder: PC - Audacity 2.1.2
File: Brandenburg no3 First Movement.aup
- Sync tracks and trim