thoughts on Digitech Space Station eprom copying?

[digi2t]

You're very welcome. I'm happy to see that you got it sorted out. Good on ya!

[Govmnt_Lacky]

Yep!! Thats the mod!

Ok then... I guess we will see you back when you want to add the other pedals in there (200, 400) 

[mwynwood]

Yep!! Thats the mod!

Ok then... I guess we will see you back when you want to add the other pedals in there (200, 400) 

haha yeah, that'd be the next logical step... if my sanity can stand it!
Dare I ask... pray tell, what is involved? *peeks inside Pandora's box*

[Govmnt_Lacky]

Dare I ask... pray tell, what is involved? *peeks inside Pandora's box*

A rotary switch (in place of the toggle you have now), a few more EPROMs, and some wiring! 

[mwynwood]

Hmm I think I could hack that...
Did I read somewhere that there was documentation being produced explaining the process?

[Govmnt_Lacky]

Hmm I think I could hack that...
Did I read somewhere that there was documentation being produced explaining the process?

Already done!

Dino has it in his folder in the Gallery 

[digi2t]

XP-ALL and XP-ALL+ build doc;

http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=50457

Like G_L says, not much more left to do for the "Full Monty".

[OptiMitch Prime]

Hey guys,
Just wanted to start off by introducing myself and extending a huge thank you to Dino and G_L for making this info available to everyone and sharing their help and experience as well. I've learned so much just by going through the build guide and building my own xp-all+. So thank you again and if ever we meet, beers are on me! 
I wanted to post to ask if Maj ever got the issues worked out with his xp? Ironically, I'm having the EXACT same issue with my build and I haven't been able to figure it out yet. Same issues here; 1 is xp100, 2 is dead, 3 is xp200, and 4 is xp400. Any ideas or things I could try to sus out what could be going on? Thanks again guys

[Govmnt_Lacky]

@Prime

Are you using the adapter board that Maj made?

The best thing would be to go to Dino's build doc for the XP ALL+ and look at his adapter board. Use that as a guideline for measuring yours and see if there are differences. His was done on vero BUT, you can follow the path and see if your adapter board is a work-alike. I dont think we ever got true confirmation that the fabbed adapter boards were 100% accurate.

Other than that... double check your wiring to the rotary switch. That switch is very easy to get contacts mixed up.

Let us know how things turn out and Good Luck 

[marmaliser]

I think he meant Moj who didn't use my adapter and got the exact same problem as me.  Mine are both sat there still with the same errors.  Need to get them sorted

So that's 3 people and 4 builds with no commonality re parts between them but the EXACT same problem

[Govmnt_Lacky]

I gues the questions that need to be asked are:

- What rotary switch did you use?
- Did you use the 27C1001 EPROM chip for all 4 of the programs?
- If so, Who programmed them?
- Where did you get the files?

[marmaliser]

Rotary - As per Doc .  Bought from eBay
Yes XP all plus so 27C1001 and 27C1010
Programmed by me for moj and myself but he also tried one from digi2t with same results
Files were from the repository here. 

Read back and you will see that I think we exhausted the possibility of it being the chip or the programming

I think the only successful xp all plus mod is digi2t's ?

[OptiMitch Prime]

I made both a vero and through hole perf board adapters. Same results w/ both. I also checked connection on ram pins and everything checks out. The 74HC ic was already installed as I'm building out of an xp-400, so that should be ok. I also used the rotary switch as per the build doc, from ebay and am using the 27C1001 eprom. I programmed it with a tl866cs programmer using the xp-all bin file from the gallery here. I have double and triple checked my switch wiring and everything seems to check out. Very confusing. I'll try to post some pics tonight, maybe someone will notice something I missed. Could having the vss wire from the adapter board, relay ground, and led grounds connected to the same pin on the rotary switch be causing an issue? I don't think that would be an issue but I'm running out of ideas and I'm hoping it's something minor and overlooked causing it as the other three modes work and are being successfully read from the eprom. Troubleshooting is always the roughest part of a build.

[digi2t]

This is very weird. It kind of reminds me of a problem that a forumite had with a Colorsound Vocalizer build. He fought with it for nearly a month, posting here several times a week. This included several pictures. Finally, in desperation, he sent it to me. After half an hour on the bench, I traced it down to a wrong resistor value on the board. One red band, that should have been orange. Unfortunately, the pictures he posted weren't hi-rez enough to make that out.

Moral of the story;

No matter how much back and forthing we did here, it didn't help. In some cases, if we can't see it, we can't help. It sucks. Especially since it doesn't seem to be an isolated problem.

Insofar as the Vss/ground question, no it shouldn't. Mine are all wired together. But, could you try something; disconnect the LED's, and relay, and try switching the chip alone. Let us know what happens. I'm just curious as to whether the Vf of the LED's might be screwing with something here.

[Govmnt_Lacky]

I hate to say this but.....

Every time I see these posts it reassures me that I made the right choice in sticking with the old fashioned stacked 27C256 chips 

[marmaliser]

Insofar as the Vss/ground question, no it shouldn't. Mine are all wired together. But, could you try something; disconnect the LED's, and relay, and try switching the chip alone. Let us know what happens. I'm just curious as to whether the Vf of the LED's might be screwing with something here.

I never added the LED's and totally disconnected the relay switching to test by  powering down in between changes but the same result.

[OptiMitch Prime]

Same results here with the led's and relay grounds disconnected. I'm learning as I go, as far as EPROMs and smd chips in general, so this has me quite stumped.
I did some more poking around and checked dc and ac voltages on pins A14-16 when switching and got the following:
DC
Pos.1: all=0V
Pos.2: A14=0V, A15=0V, A16=5.1V
Pos.3: A14=66mV, A15=5.1V, A16=0V
Pos.4: A14=0.41V, A15=5.1V, A16=5.1V

A14 seems suspect to me and I got the same reading tracing it to U15.
AC voltages were all consistent w/ DC as far as spec in the different positions. All seemed fine except A14 in Pos.3 again seemed low. Also all AC voltages peaked and dropped from their voltages when read, except A14 in position 4 was steady at 1.1V-AC. (and of course A14 position 3, which was next to nothing to begin with).

According to the datasheet, if I understand it correctly, the pins in question need to see a minimum of 0.4V

It's also odd to me that the readings seemed ok on position 2, which doesn't load and readings on position 3 seemed off and it loads as xp-200.

Again, I'm still making sense of this as I go but I just wanted to share my findings so maybe we can compare and narrow down what's going on. I'm still wondering if my eprom is definitely programming correctly, but have compared and verified it to the one in the gallery, so I'm assuming it's ok.

[digi2t]

I did some more poking around and checked dc and ac voltages on pins A14-16 when switching and got the following:
DC
Pos.1: all=0V
Pos.2: A14=0V, A15=0V, A16=5.1V
Pos.3: A14=66mV, A15=5.1V, A16=0V
Pos.4: A14=0.41V, A15=5.1V, A16=5.1V

Looking at the switching, it seems to me that you should be getting this;
Pos.1: all=0V
Pos.2: A14=0V, A15=0V, A16=5.1V
Pos.3: A14=5.1V, A15=5.1V, A16=0V
Pos.4: A14=5.1V, A15=5.1V, A16=5.1V

G_L, can you confirm that the switching scheme is the same for your unit? I'll double check mine tonight, including voltages.

[Govmnt_Lacky]

G_L, can you confirm that the switching scheme is the same for your unit? I'll double check mine tonight, including voltages.

Sorry brother.... I never got into all that new-fangled switching and adapter board stuff   

Im still working with the 27C256 chips stacked. 

[digi2t]

G_L, can you confirm that the switching scheme is the same for your unit? I'll double check mine tonight, including voltages.

Sorry brother.... I never got into all that new-fangled switching and adapter board stuff   

Im still working with the 27C256 chips stacked. 

DOAH!! That's right. Sorry bro. I'll check my voltages tonight.