Potential homemade XenoGC Fix

I made a homemade XenoGC with Atmega8L but realized that many times (sometimes like 50% of the time) the light would not turn on at all (even though it was receiving power), and thus would not boot backup games. When it lit up, it booted games without issue. After resoldering several times and testing using a multimeter to rule out wiring issues, I tried a few other things. I've installed non-homemade XenoGC several times without any issues.

I tried soldering a wire between the Reset spot on the bottom left of the GC drive to the Reset pin (pin 1) of the Atmega 8L and now it works 100% of the time. To test it out I disconnected it, tried it again, and it often wouldn't light up like it's supposed to, then I reconnected the reset pin and it worked perfectly.

I read elsewhere online where somebody had the same problem with the homemade XenoGC not working 100% so I figured it wasn't just me, but if you're having this problem, try what I posted.

 

The point of putting a 1K resistor on pin 1 of the AVR MCU is keep it not reset. If the pin has no voltage it won't start.

I had absolutely no issue when I cloned the XenoGC. I had to guess the fuses because there were no clear instructions on how that was supposed to be programmed but read the ATMEL datasheet with attention will certainly open your mind.

The ATMEGA8 is certainly a awesome piece of engineering:

http://youtu.be/Rg_Z0-tQZW0?list=UUKYNJii6IvCcYSx82t-51qg

It's C compiled code and I'm not using even half of the flash yet ... lol

Only problem with the MEGA8 is a severe lack of outputs. But for this use as modchip it's certainly not a issue haha

 

I had problems with a selfmade Xeno GC too, sometimes it started and sometime it didn't. I figured it must have been a freak Gamecube, ended up selling it and buying a Wii.

 

Why would you make a XenoGC when the real thing costs $5 and can be direct mounted?

 

Because the ATMEGA8 chip costs like 1 or 2 bucks and a lot of people like to do their stuff themselves. Also the code being free and open now, is a big reason, too...

 

Maybe the homemade Xeno is picky, maybe it doesn't like certain GCs. I have no idea, but joining the 2 Resets made it work almost perfectly for me whereas before it wasn't.

As for why? That's kind of a stupid question, because you could say the same thing about anything else online that you can make. It was a fun project and I made several chips. I don't know if you can find Xeno's for $5 anymore, most places want $8+ for it (don't forget about shipping), and as l_oliveira pointed out, the Atmega8 chip is only like $1.50.

 

Oh, that problem sounds familiar: The fuse settings shown in the gc-forever wiki (lfuse 0xc4, hfuse 0xd9) do not enable the brown-out detection, after turning it on (lfuse 0x84, hfuse 0xd9) the chip was completely reliable for me. Unfortunately the update tool does not touch the fuses, so you need to temporarily disconnect the chip and use an external ISP programmer to change the fuse values.

As for "why build it yourself if you can buy it": All the fuss needed to boot a game in 480p mode on my PAL cube for testing became too annoying and I had an ATmega8L in my parts bin - building the modchip from that was faster than ordering one and waiting a few days. =)

 

LOL guys, do you realise that the fuses are NOT copy protected ? You can read the fuses of a legit chip anytime you want.

And yes, the fuses are critical to the operation of the chip. Particularly on the case of the xeno chip. I am not sure how the fuses are supposed to be set up like (been a long time ago since I played with it) but I don't think the xeno GC has any sort of bootloader built in it.

The only thing I remember the top of the mind is that the clock oscillator configuration was critical. You want it to run with the internal clock which if I am not mistaken is 8Mhz.

Also I think the modchip code do use the eeprom section and you had to program that properly for it to operate correctly, too. (particularly I think the eeprom data was something small as three to 6 bytes but the thing would not work without that)

 

I set the fuses as per the instructional:
http://www.gc-forever.com/wiki/index.php?title=XenoGC_Clone#Programming_Software

So fuses aren't the problem.

The first attempt I completely forgot to program the fuses and the chip just did nothing. Then I programmed fuses and it worked, but not everytime.

 

I believe the last part of the discussion was about the possibility of the fuses on that WIKI being wrong, not about you setting them wrong.

I also mentioned the eeprom, because I remember that giving me headaches.

 

I don't believe I ever had to do anything with the EEPROM, nor is it mentioned anywhere in the instructional. Unless it's done automatically and I just didn't realize it.

 

Some programmers do upload eeprom data automatically, yes. But I believe avrdude does not. (which is a good thing really, make you stay sharp about the stuff you do).

 

I think the wiki is wrong - in any case, the fuse values they suggest go against Atmel's recommendations.

According to the datasheet, 0xC4 = BOD disabled, Minimum startup time, 8MHz internal RC (table 88 on page 217)

But if you look at Table 10 on page 30, it only recommends setting the shortest startup time if you have the BOD enabled. I can absolutely see this causing unreliable startup.

 

What would you recommend to fix the problem? I could possibly test it out later at some point and see if it improves booting, because clearly a few people like myself aren't getting perfect booting as it is now.

 

Exactly what the other poster recommended - set the fuses to 0x84, so the BOD is enabled.

 

^ Alright, I'll try that out later and see if it makes a difference. Thanks guys.

 

Tch, don't you know there are no stupid questions?

A three word google search will find you plenty of places you can buy bags full of XenoGCs or clones for as little as $3 shipped. And DIYing stuff is great if you have time to futz around, but my Xeno works perfectly all the time and didn't require a (currently inconclusive) forum thread to get there.

 

Do you go around on all DIY threads and write things such as "just buy it"? Thanks for (not) contributing.

It's not necessarily inconclusive anyways because the fix I originally posted (if you even read it...) works for me anyways.

BTW, I'd like to see a link for these sites where they sell you "bags full of XenoGCs or clones for as little as $3 shipped". Not saying it doesn't exist, I'd just like to see it.

 

Hey, I'm not trying to pick a fight here, my original "stupid" question was asked because I was interested inn knowing if there was some benefit to the DIY solution, I'm a logical person, I like to have concrete reasons for doing things, there might have been extra functionality for all I knew. I'm not that "just buy it" guy at all, but you can read all my past posts, they speak for them selves, I love tinkering with consoles, but I also have constraints on my time that proclude me experimenting when a tried and tested solution exists. No offense was meant.

As for the $3 Xenos? You wants $3 XenoGCs? We gots $3 XenoGCs: http://www.aliexpress.com/item/New-XENO-Chip-for-gc-gamecube-game-cube-5PCS-LOT/1890444762.html

 

A good example of benefit at doing something yourself is the potential of learning something useful during the process of making it work. The thing with the fuses was a "minor detal" I never noticed because I've been using that very same AVR chip (ATMEGA8) with a completely different configuration (I'm using it with 16Mhz crystal, aka: Arduino) but if I ever need to make a simpler device and need the internal clock of the ATMEGA8 I'll now know of the important detail I missed while reading the datasheet.

Anyway doing stuff yourself is always big fun.