Game Boy Advance HDMI Adapter

[Woozle]

I'm disappointed you're still claiming the Game Boy Player is plagued with stutter.

I made GBI because I knew of madVR's smooth motion frame rate conversion. I had that feature working long before audio.
And for those that dislike it, there are video modes with a multiple of 59.7276 Hz.

To be fair, with the official GBP software it is plagued by stutter. For the average user that's the experience they get. I've never used GBI, it looks amazing from everything I've seen and I do try to recommend it when I can. I'm going to add visual comparisons to the GBP on the page eventually, but I'm only going to compare against at best the official component cables and not the various HDMI options for the same reason. There's already a few people who are going to do more in-depth comparisons for all the GBA on TV options in video reviews on their youtube channels.

I'm very interested in this project. I'd definitely like a native refresh rate option (or as close to it as possible) as my set is fine with around +/- .5hz from 60hz.

Also, if there's no DAC, a good solution would be to make sure it will output to a Tendak HDMI->RGBHV converter, which are affordable, good quality, are fine with weird refresh rates, and which even pass 240p properly for use with a PVM/BVM.

Sorry, it's going to target exactly 60Hz with the new oscillator. It's not that simple to drive the HDMI output at the GBA speed...whereas its easy to dial up the GBA to exactly 60hz. I don't plan on supporting 240p output or switchable output resolution, just fixed 720p. If you want native GBA speed, just keep the original oscillator on the GBA board..you'll get some screen tearing, but the GBA will run at stock speed.

This is awesome news Woozle, I've been hoping for that project of yours to come through soon. Stoked about this

Will the 240p rgb option be a DAC adapter that plugs in the HDMI version, or a completely different version of the kit (it's own thing plugged in the GBA)?

240p RGB would be an entirely separate board similar to Borti's advanced RGB kit. That's a long way out though.

[becker]

Very cool. You peaked my interest in getting a GBA to hack. How are you handling the audio? The GBA schematic looks like the CPU outputs analog left and right into an amp. Do you pick up the audio before or after the amp? Does your FPGA have ADC? I'm having trouble finding good information about the audio hardware. I was hoping it was I2S but that doesn't seem to be the case.

[Woozle]

Very cool. You peaked my interest in getting a GBA to hack. How are you handling the audio? The GBA schematic looks like the CPU outputs analog left and right into an amp. Do you pick up the audio before or after the amp? Does your FPGA have ADC? I'm having trouble finding good information about the audio hardware. I was hoping it was I2S but that doesn't seem to be the case.

I grab it right at the CPU output and just read the PWM audio with an fpga, no ADC is involved. Sounds pretty good.

Earlier I mentioned that I was going to swap the 100 MHz oscillator for a 74.25 MHz oscillator to get my hdmi vsync at exactly 60 Hz. The swap went ok and it brought the hdmi vsync up to 60 Hz. Code seems to be wrapping up, not sure what I would modify at this point.

[tusecsy]

Very cool. You peaked my interest in getting a GBA to hack. How are you handling the audio? The GBA schematic looks like the CPU outputs analog left and right into an amp. Do you pick up the audio before or after the amp? Does your FPGA have ADC? I'm having trouble finding good information about the audio hardware. I was hoping it was I2S but that doesn't seem to be the case.

I grab it right at the CPU output and just read the PWM audio with an fpga, no ADC is involved. Sounds pretty good.

Earlier I mentioned that I was going to swap the 100 MHz oscillator for a 74.25 MHz oscillator to get my hdmi vsync at exactly 60 Hz. The swap went ok and it brought the hdmi vsync up to 60 Hz. Code seems to be wrapping up, not sure what I would modify at this point.

any kinda estimates on when this may be available? voultar on the retro roundtable had me drooling lol.