Interface!
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george lazenbleep
Dec 2, 2007, 1:42:14 PM12/2/07
to pushpin, george.l...@googlemail.com
ok, just before i start,is this the order of proceedings? - MIDI into
opto isolator via 220 k resistors,(add power and signal conditioning
to opto ) then pin 6 of the opto to pin 13 on the max 232 and pin 14
to ground. after that its pin 4 of the max to the sd in, powering
both chips from the gb cable.
is this the signal flow?
and if so has anyone heard from lameboy?
;#
opto isolator via 220 k resistors,(add power and signal conditioning
to opto ) then pin 6 of the opto to pin 13 on the max 232 and pin 14
to ground. after that its pin 4 of the max to the sd in, powering
both chips from the gb cable.
is this the signal flow?
and if so has anyone heard from lameboy?
;#
Ove Ridé
Dec 2, 2007, 2:15:40 PM12/2/07
to pus...@googlegroups.com
See the comment I left on my blog.
Ditch the Max-232. If anything you should 220 Ohm resistors on the
left side of the, not 220 kOhm.
My schematic should work fine, except for the resistor values. Replace
R1 with a 5k6 and R2 with a 1k2, and it should work. Also, you may
want to connect a 74hc04 (Schmitt trigger inverter) between the opto
and the GB. Connect the output from the opto to an input of the
74hc04. Connect the output of that gate to an input of the next gate.
(So you invert it one more time) Connect the second output to the SD
pin.
Ditch the Max-232. If anything you should 220 Ohm resistors on the
left side of the, not 220 kOhm.
My schematic should work fine, except for the resistor values. Replace
R1 with a 5k6 and R2 with a 1k2, and it should work. Also, you may
want to connect a 74hc04 (Schmitt trigger inverter) between the opto
and the GB. Connect the output from the opto to an input of the
74hc04. Connect the output of that gate to an input of the next gate.
(So you invert it one more time) Connect the second output to the SD
pin.
That should be it.
--
/Ove
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george lazenbleep
Dec 2, 2007, 6:30:28 PM12/2/07
to pushpin
ya saw your comment, no worries. so basically the opto is converting
the current loop to an isolated pulse? is the inverter just used a a
buffer? cheers for the help
:#
the current loop to an isolated pulse? is the inverter just used a a
buffer? cheers for the help
:#
On Dec 2, 7:15 pm, "Ove Ridé" <nitro2...@gmail.com> wrote:
> See the comment I left on my blog.
> Ditch the Max-232. If anything you should 220 Ohm resistors on the
> left side of the, not 220 kOhm.
> My schematic should work fine, except for the resistor values. Replace
> R1 with a 5k6 and R2 with a 1k2, and it should work. Also, you may
> want to connect a 74hc04 (Schmitt trigger inverter) between the opto
> and the GB. Connect the output from the opto to an input of the
> 74hc04. Connect the output of that gate to an input of the next gate.
> (So you invert it one more time) Connect the second output to the SD
> pin.
>
> That should be it.
>
> See the comment I left on my blog.
> Ditch the Max-232. If anything you should 220 Ohm resistors on the
> left side of the, not 220 kOhm.
> My schematic should work fine, except for the resistor values. Replace
> R1 with a 5k6 and R2 with a 1k2, and it should work. Also, you may
> want to connect a 74hc04 (Schmitt trigger inverter) between the opto
> and the GB. Connect the output from the opto to an input of the
> 74hc04. Connect the output of that gate to an input of the next gate.
> (So you invert it one more time) Connect the second output to the SD
> pin.
>
> That should be it.
>
george lazenbleep
Dec 10, 2007, 8:47:01 AM12/10/07
to pushpin
ok so i had a crack and i can't make it work. i used ove/nitro's
diagram with the newer components. also used a hex inverter (40106) as
a buffer.
was able to check that i had midi coming into the opto, and power from
the gbc. i used an led as an indication of both. the midi in blinked
away quite happily, but it looked like i was just getting a steady +5v
out of the opto. anyone have any ideas?or has anyone had any success.
ez
:#
On Dec 2, 11:30 pm, george lazenbleep
> > -----END 2ROT13 MESSAGE------ Hide quoted text -
>
> - Show quoted text -
diagram with the newer components. also used a hex inverter (40106) as
a buffer.
was able to check that i had midi coming into the opto, and power from
the gbc. i used an led as an indication of both. the midi in blinked
away quite happily, but it looked like i was just getting a steady +5v
out of the opto. anyone have any ideas?or has anyone had any success.
ez
:#
On Dec 2, 11:30 pm, george lazenbleep
>
> - Show quoted text -
Ove Ridé
Dec 10, 2007, 9:30:59 AM12/10/07
to pus...@googlegroups.com
On 10/12/2007, george lazenbleep <george.l...@googlemail.com> wrote:
>
> ok so i had a crack and i can't make it work. i used ove/nitro's
> diagram with the newer components. also used a hex inverter (40106) as
> a buffer.
> was able to check that i had midi coming into the opto, and power from
> the gbc. i used an led as an indication of both. the midi in blinked
> away quite happily, but it looked like i was just getting a steady +5v
> out of the opto. anyone have any ideas?or has anyone had any success.
> ez
> :#
Exactly my problem too. First off, have you tried the new values that>
> ok so i had a crack and i can't make it work. i used ove/nitro's
> diagram with the newer components. also used a hex inverter (40106) as
> a buffer.
> was able to check that i had midi coming into the opto, and power from
> the gbc. i used an led as an indication of both. the midi in blinked
> away quite happily, but it looked like i was just getting a steady +5v
> out of the opto. anyone have any ideas?or has anyone had any success.
> ez
> :#
I wrote in the blog comments for my how-to page?
Right now Im having some domain problem, so you can't reach it right
now. When it works again, you can reach it at:
<http://gameboygenius.8bitcollective.com/wordpress/?page_id=96>
Anyways, the relevant parts are this schematic:
<http://localhosted.net/~nitro2k01/images/pushpin-midi-gameboy.png>
As well as this addendum:
"Try replacing R1 with a 5k6 and R2 with a 1k2, and see if it's any
better. Also, make absolutely certain that R3 is not a 220k, which
would guarantee that the circuit wouldn't work! "
Putting an inverter circuit afterwards is a good idea, but remember to
invert it twice so you'll get the original signal.
/Ove
-----BEGIN 2ROT13 MESSAGE-----
Low Bitrate Netlabel: <http://flb.gg8.se/>
george lazenbleep
Dec 10, 2007, 1:30:42 PM12/10/07
to pushpin
yeah, did all that, still just getting +5 out, ie no data!
:#
On Dec 10, 2:30 pm, "Ove Ridé" <nitro2...@gmail.com> wrote:
:#
On Dec 10, 2:30 pm, "Ove Ridé" <nitro2...@gmail.com> wrote:
george lazenbleep
Dec 11, 2007, 6:04:03 AM12/11/07
to pushpin
shot in the dark as i'm not actually infront of the circuit, but does
r2 need to be a pull up? what would happen if it was pull down?
:#
On Dec 10, 6:30 pm, george lazenbleep
r2 need to be a pull up? what would happen if it was pull down?
:#
On Dec 10, 6:30 pm, george lazenbleep
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