MythVo

[Dark_Aaron]

Hello everyone,

I've decided I wanted to build a MythTV box, but decided I wanted to use a Humax DRT800 as the case. This is obviously going to be a challenge, seeing as there's space constraints that the average PC manufacture doesn't have to account for. I just wanted to share with you guys my progress on this mission and share some of my ideas for this. I'd also love to get some input from you guys on it.

Here's the starting point, with no modification at all.
Front:


Back:


Insides:


Now, to start tearing into this thing.
Removed the drives and mounts:


The front panel.


Starting to solder some wires for what was a 24 pin ribbion cable connector.




This is a cheap Arduino Mega clone I got off ebay:
I removed the pins and will solder the 24 pin connector of the front panel to this. I'm not quite sure how to interface with the front LCD yet, it appears there's some kind of controller IC under it, but I don't want to desolder the LCD to be able to read it. If anyone has info, your comments would be appreciated.

I also plan to rig up something with some transistors so that when the computer is on the arduino will just write HIGH (+5V) to a pin and that will cause the signal from the TiVo button to go over the serial connection to the board and tell MythTV that the home button was pressed. But when the pin from the arduino is LOW, then I'm going to have it send the signal to the motherboard's power connector.



This is kind of how I plan to mount the arduino. I removed the board that had the firewire, and video inputs. I also plan to desolder the DC power connector and just tap into what is coming from the supply, assuming that is 7-12V. (Just need to know how much the LCD and it's components require.)

I don't think I'll be able to reuse the TiVo's power supply, so I'm going to take a normal ATX one and move it onto a PCB that'll fit into the TiVo's case better.

As for the motherboard, I'm not sure what I'm going to do yet. I'm thinking the DVD drive has to go, or I might can fit a laptop one inside it, not sure.

I plan to make some 'L' shaped PCI and (whatever else) adapters so that I can put cards in it too. I'm thinking about an HD tuner card and a video card with HDMI out. Not sure if the heatsink will be a problem either.

But that's my progress so far, I'll keep you guys posted on my progress.

[mr.unnatural]

A mini-ITX motherboard should fit with no problems. You can also use a pico-PSU power supply if you find that space is getting to be a premium. I would imagine that the MythTV website would have a list of compatible hardware that can be used. You may even be able to shoehorn a micro-ATX mobo into the case, but that's going to be a bit tight. Consider using an SSD for the OS drive and a standard 3-1/2" drive for recording.

[Dark_Aaron]

Originally Posted by mr.unnatural

A mini-ITX motherboard should fit with no problems. You can also use a pico-PSU power supply if you find that space is getting to be a premium. I would imagine that the MythTV website would have a list of compatible hardware that can be used. You may even be able to shoehorn a micro-ATX mobo into the case, but that's going to be a bit tight. Consider using an SSD for the OS drive and a standard 3-1/2" drive for recording.

Hmm, I thought about a mini-ITX. Really, it's more likely I'll try to fit a micro-ATX board. The pico-PSU is a good idea. Right now, I'm questioning how to interface with the LCD. I'm hoping it's some kind of serial, but then I will have to figure out the protocol. I should probably remove the LCD to get the IC's model number and such then resolder it. Or carefully try to bind the LCD forward and then read it back, but I've had bad luck in the past doing that, pins break really easy when you bind them like that. :P

The SSD is a good idea too, I'll look into it. I also had another idea of being able to run emulators on this. On my current MythTV install I have been using a Nintendo Wii remote as the control, so I'm thinking that will be perfect for emulation of NES games and such. For other games like the PlayStation 1, I could use my PS3 controller. Gotta love bluetooth. :P

[Dark_Aaron]

I think I'm going to order some of these in PCI and whatever else format I'll need. http://www.amazon.com/PCI-Riser-adap...ref=pd_cp_pc_3

That'll make mounting the cards in the back not as limited as to where they can be mounted. I'm probably also going to mount a secondary fan inside somewhere. Just for redundancy. For the back panel, I'm probably going to use a dremel tool or something else just to cut a huge hole in the back. Then get some sheet metal cut that to size then mount it over the hole. Then in that I'll cut the holes for the IO ports and such.

I'll let you guys know if I end up doing that, I'm also not sure as to the specs. Since I want to do HD, I should probably go with something like this: Low Profile Half Height nVIDIA GeForce 512MB PCI-E

I'm thinking 512MB of video ram should be enough. I'm guessing that at least. I guess it also depends on what kinda emulators I want to run on it.

I'll do some research on what sound card will work best. I might also put in built in wifi and builtin bluetooth is planned.

[Dark_Aaron]

Well. as it turns out the myhtv wiki says,

Several options exist in Windows to capture HDCP-free HDMI signals. No linux drivers are available for any of these cards, they rely on directshow filters for compression, and the native compression is a poor, proprietary codec. Until these hurdles are overcome, current methods of HDMI capture are impractical for MythTV. Even then, the limitations placed on the device by copy protection make this impracticable.

Which is fine with me if I don't have HD recordings. I can goto the local computer store, and get a used Hauppauge PVR-150 for around $10.

[Dark_Aaron]

Here's an update on the progress.



I got the Arduino's DC plug unsoldered and soldered in some wires to it's places which connects to the original front panel leads. This will connect to the PSU (I might add a down step transformer if needed.)

Here's everything mounted. As of right now I only have the buttons wired in. Next I'll wire in the LEDs. For the display I'm still not sure, I'm thinking about just ripping it off and using a LCD I know is compatible with the arduino. (This would probably be better, since it's an actual LCD. Not just a bunch of multi-segment LEDs.)



This is probably the motherboard I'll use. It's a micro-ATX board. It seems like once I get the fabrication parts done it'll fit nicely. Right now it just has an AMD Athlon 64. I know that I can upgrade it to an Athlon 64 x2 which I think would give me better performance. I'm probably just going to put a standard definition tuner card in it. With the Nvidia card I mentioned in a previous post.

I'm probably going to put 4GB of ram into it as well.



and here's a front view of it. The panel still fits as it was intended to.

[Dark_Aaron]

I didn't realize it, but the back IO shield was held in my rivets. So I just punched those out and now the mother board aligns with one screw. I'm defiantly going to need motherboard posts.



Also an interesting note, when I was looking at the cut outs in the IO shield, it appears there is a cutout for an HDMI cable. Which is kind of shocking considering the age of this thing.