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Personal 4 port cartridge expansion project

4 port cartridge Expansion

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#76 sparkdrummer ONLINE  

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Posted Sat Apr 8, 2017 4:49 AM

Attached File  DSC09963.JPG   904.76KB   6 downloads

 

5 cartridge port expander



#77 Sinphaltimus OFFLINE  

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Posted Sat Apr 8, 2017 4:53 AM

attachicon.gifDSC09963.JPG

 

5 cartridge port expander

LOL! Nice one. But can it do uberGROM?



#78 Lee Stewart OFFLINE  

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Posted Sat Apr 8, 2017 9:41 AM

LOL! Nice one. But can it do uberGROM?

 

Surely not if it is what it seems—two daisy-chained Navarone Widgits!

 

...lee



#79 Sinphaltimus OFFLINE  

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Posted Sat Apr 8, 2017 3:09 PM

Well, it's all wiored up and with the exception of the following 3 issues, this project might have been done today.

 

I found 3 issues. I'm afraid they might be a faulty switches, port 2 and port 3 issues might also be broken solder points that I'll have to trace out to locate where the open is.

With port 1 selected, I'm getting connectivity on port 2 pin 21. <suspect bad switch pole - I can change this fairly easily.

With port 2 selected I'm not getting any connectivity on port 2 pin 34. <suspect bad switch pole or broken solder point.

With port 3 selected I'm not getting any connectivity on port 3 pin 21. <suspect bad switch pole or broken solder point.

So I still have some work cut out for me. But not today, I've been at this most of the day. I'll have to pick it up again tomorrow morning.


Edited by Sinphaltimus, Sat Apr 8, 2017 3:09 PM.


#80 --- Ω --- OFFLINE  

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Posted Sat Apr 8, 2017 3:17 PM

Sinphaltimus,

   Has anyone yet told you about "the TI demonstration curse"?  It's TRUE!



#81 Sinphaltimus OFFLINE  

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Posted Sat Apr 8, 2017 4:58 PM

Sinphaltimus,

   Has anyone yet told you about "the TI demonstration curse"?  It's TRUE!

No. But I think I have it.


Oh and this:

Project Album

 

EDIT:

OK, so man handling this thing loosened up a few connections. So I tightened them up. Also, one of my mounted jumpers came loose which would explain the short of GROM2. So I tightened everything up, and tested my switches, they work as far as I can tell. BUT, no matter what port is selected, I can load a cart from any one of the ports. On other words, if I have port 1 selected, the cart loads up (PARSEC) just fine on port 1, 2, 3 and 4. It really is behaving as though it is wired straight through without the switches. Each GROM operates fine independant of the switch selection.

And yet, when I trace continuity from console port through grom port, everything checks out.

I get no connections across pins 21, 31 and 34 on GROM ports that are not selected by a switch. I honestly do not know what I did wrong. It makes zero sense to me.

So bizarre.  I'm actually contemplating quickly building a second one without the connectors and just soldering wires directly to pins and such. If I work on it every night, I might get it done before FestWest. But I have to jump between trouble shooting this more and more and more and more until the solution presents itself and actually starting from scratch with a much more manageable design.

I guess I'll sleep on it first.


Edited by Sinphaltimus, Sat Apr 8, 2017 5:56 PM.


#82 Shift838 OFFLINE  

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Posted Sat Apr 8, 2017 8:05 PM

No. But I think I have it.


Oh and this:

Project Album

 

EDIT:

OK, so man handling this thing loosened up a few connections. So I tightened them up. Also, one of my mounted jumpers came loose which would explain the short of GROM2. So I tightened everything up, and tested my switches, they work as far as I can tell. BUT, no matter what port is selected, I can load a cart from any one of the ports. On other words, if I have port 1 selected, the cart loads up (PARSEC) just fine on port 1, 2, 3 and 4. It really is behaving as though it is wired straight through without the switches. Each GROM operates fine independant of the switch selection.

And yet, when I trace continuity from console port through grom port, everything checks out.

I get no connections across pins 21, 31 and 34 on GROM ports that are not selected by a switch. I honestly do not know what I did wrong. It makes zero sense to me.

So bizarre.  I'm actually contemplating quickly building a second one without the connectors and just soldering wires directly to pins and such. If I work on it every night, I might get it done before FestWest. But I have to jump between trouble shooting this more and more and more and more until the solution presents itself and actually starting from scratch with a much more manageable design.

I guess I'll sleep on it first.

 

I know I tore my 2 port down 4 or 5 times working on troubleshooting.

 

I feel your pain but yours is twice as much as mine!



#83 Sinphaltimus OFFLINE  

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Posted Sat Apr 8, 2017 8:31 PM

 

I know I tore my 2 port down 4 or 5 times working on troubleshooting.

 

I feel your pain but yours is twice as much as mine!

 

 

LOL! That's exactly what  I decided to do. I unwired everything, reinforced, moved a couple of things and have started rewiring everything again, but differently this time. Should make it look neater and easier to troubleshoot if need be when I'm done.

I got pins 1-21, 31, 34 done. Resistor and switches done. Then I ran out of gas. Gonna turn in now and pick it up again bright and early to finish the last group of connections then we'll see where I stand. 



#84 Sinphaltimus OFFLINE  

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Posted Sun Apr 9, 2017 8:34 AM

OK, stumped. I hit up the 2 folks who have been helping along this far and hopefully one of them finds the issue in my drawings otherwise, I am at a complete loss. Totally stumped.

I posted the update here to get more eyes on it in case we're overlooking something.

Switches are working as expected but the entire thing is behaving as if it is wired straight through (all switches engaged at once).

Example, I put one cart (parsec) in to port 1 and it works with the console no matter what switch I have selected.
Same results if parsec is in ports 2-4.

Below is the final schematic showing all wires.

And then a very crude drawing of the actual relevant wires and how I physically split and connected them. All remaining wires are straight from console port to GROM port (not illustrated in crude drawing).

 

Attached File  Diagram6.png   421.54KB   2 downloads

 

Attached File  Wired.png   127.13KB   2 downloads
 

 

 

UPDATE: As per Shift838's suggestion, I checked voltages at the GROM ports and from the edge connector to the GROM the voltage drops from 5v to 2.5 essentially. And no voltage on G4. This is with Port 1 selected as active. 

So somethings not right, I'm thinking my materials. Not sure If I'll have time to build another before FW17, I may start it anyway. I'll bring this concoction with me to FW anyway. It's easy to tear down and build back (takes about an hour). Maybe I'll sit at a back table and troubleshoot it there with someone. Dunno how feasible that would be.


UPDATE 2: 

I'm beginning to doubt these switches. A couple of times when testing they appear to not function as expected. So pushing one in then popping it out again by selecting another switch sometimes requires me to do it twice. I guess I didn't know what to expect using these very old radio shack a/v switch boxes. so I ordered some switches that will at least give be stability there. I'll connect them when they arrive Thursday. At least then I will know if my hunch was correct and get this project to work. 


Edited by Sinphaltimus, Mon Apr 10, 2017 3:30 PM.


#85 Sinphaltimus OFFLINE  

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Posted Sat Apr 15, 2017 2:20 PM

Despite the fact that others have have success with this build....

I can't get it to work. Pretty much the same results. It's behaving as if the wires are straight through with no switches attached. So I can use anyone port independent of the others as long as there are no other carts installed. That's about it. I'm at a complete loss. the switches are new, they pass continuity testing and all my wires and resistors are in place as they should be. I guess i can bring it to FW to show off how not to make a switchbox.



#86 Airshack OFFLINE  

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Posted Thu Apr 20, 2017 1:15 PM

attachicon.gifDSC09963.JPG
 
5 cartridge port expander


OMG! That's brilliant and way less work! LMAO!!


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#87 Airshack OFFLINE  

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Posted Thu Apr 20, 2017 1:19 PM

Despite the fact that others have have success with this build....

I can't get it to work. Pretty much the same results. It's behaving as if the wires are straight through with no switches attached. So I can use anyone port independent of the others as long as there are no other carts installed. That's about it. I'm at a complete loss. the switches are new, they pass continuity testing and all my wires and resistors are in place as they should be. I guess i can bring it to FW to show off how not to make a switchbox.


Hang in there buddy! We need you back writing games anyway. Software is where it's at!


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#88 Sinphaltimus OFFLINE  

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Posted Fri Apr 21, 2017 5:04 PM

Yeah, I've already rewritten Zombi in my head several times these past few weeks. I'm going to change the scope of the game to over-come the performance hits. One thing that's going to be a big change is spawning in zombies when one is killed so I can give the impression of a lot of zombies on a level without have to load them all and track them all at once. The only purpose for me to do this HW project was That I really do need a 4-port cartridge switcher for my console. One that works with all the popular cart formats.


Edited by Sinphaltimus, Fri Apr 21, 2017 5:04 PM.


#89 jedimatt42 ONLINE  

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Posted Sun Apr 23, 2017 12:29 AM

Despite the fact that others have have success with this build....

I can't get it to work. Pretty much the same results. It's behaving as if the wires are straight through with no switches attached. So I can use anyone port independent of the others as long as there are no other carts installed. That's about it. I'm at a complete loss. the switches are new, they pass continuity testing and all my wires and resistors are in place as they should be. I guess i can bring it to FW to show off how not to make a switchbox.

 

Maybe another pair of eyes will spot something at FW.

 

-M@



#90 Opry99er OFFLINE  

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Posted Sun Apr 23, 2017 6:31 AM

Stick with it, bud... you've put a lot of work in.

#91 Sinphaltimus OFFLINE  

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Posted Sun Apr 23, 2017 7:40 AM

Well regardless of the consensus at FW, I'm going to build a different unit when I get back. I'm going to need help getting a board design I can send in for manufacture once I have a usable schematic. Hopefully I can get a volunteer to create the file I need for OSH park. Or at least get a lot of help learning to do it myself.

#92 Airshack OFFLINE  

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Posted Mon Apr 24, 2017 8:45 PM

So am I to understand Zombie development is undead?


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#93 Sinphaltimus OFFLINE  

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Posted Tue Apr 25, 2017 3:24 AM

So am I to understand Zombie development is undead?

Ha. Yeah I suppose. It was never dead. Just got real busy. I'm starting my own business and working extra so less time off and less time for hobbies. I need this 4 port cart switcher so as soon as I have it working it's back to Zombi.
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Edited by Sinphaltimus, Tue Apr 25, 2017 3:26 AM.






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