Radica inside 5" Audiovox screen, my first portable

nubie · Post by **nubie** » Mon Feb 25, 2008 4:35 pm

Edit: New look, I just moved the grips up and sawed off the sides, now I can use it more comfortably.

Hi everyone

,

I thought I should try a portable, being my first I thought it best not to get too excited (and then of course promptly set about trying to LED mod an Audiovox D1500A/EX50 screen

), so it is a straight Legends II unit inside the original screen shell.

Picasa Web Album, Full Size: http://picasaweb.google.com/nubie07/Por ... 2478651858

I haven't figured out the battery yet ( 4 or 6 AA or AAA NiMH), I can't decide where to put them either, although the current external pack makes the unit pretty light

. I can put 2 AAA across inside the old hinge area, and two more on the other side from the Radica PCB, but I am starting to think that the LCD controller board needs more than 4.8 - 5.25 Volts, I get some flickering on some screens in some games.

What are your thoughts on two front mounted 2xAAA holders? I already have the depth in front from the controller shells, and I think I can fit 2 holders under the screen area, either with the batteries in the open, or with a sheet of the plastic folder material like the controller pods have covering them. (If that seems backwards, keep in mind I have my PC with the back out next to me, I even put a power switch on the back, I no longer need to reach behind it all the time

, turns out I use the front CD least of all on my PC, of course I am contemplating swapping the 5.25" bays with my PSU and have the perfect PC

)

More pics to follow.

nubie · Post by **nubie** » Mon Feb 25, 2008 5:00 pm

It is pretty slim, I am trying to figure out some kind of "nubs" to make holding it easier, perhaps a 1xAA holder underneath the pad on each side, either on the controller, or the case.

These are the guts, labeled, for full size and no labels see my Picasa Web album: http://picasaweb.google.com/nubie07/Por ... 7515260562

nubie · Post by **nubie** » Mon Feb 25, 2008 5:09 pm

The backlight was fun, I started Friday to get the Audiovox ready (the Radica was set to come on Saturday), I realized that the stupid U-Shaped backlight would give me trouble, but I jammed 4 LEDs into it anyway, ugh.

So I scored and snapped some real backlight material from a 15" LCD I had disassembled (overhead projector project):

http://picasaweb.google.com/nubie07/Por ... 4406885954

Lesson? Always score completely across, it will snap no matter what, at least what I needed was fine:

The LED mod is only 2 right now, I am thinking about 4, but I first want to stop some of that light leakage, I am thinking of using a thin strip of tin foil under the tape along the edges.

Right now the draw is 220 mah @ ~5 volts, so I could afford a couple more LEDs, but I am unsure whether to move up to a 6-cell solution.

nubie · Post by **nubie** » Mon Feb 25, 2008 5:44 pm

This is a nice shot, but I couldn't illuminate it enough to show the "cap" on the controller halves. I made the cap out of that plastic folder you can see to the upper left, the outside has a fairly large and deep pattern (which you see in this shot), the inside is a matte finish.

I used Gel Super Glue from the Dollar Tree store to glue it with the matte surface facing the screen. I still haven't finished trimming it, but it doesn't look too bad.

sam_thornley · Post by **sam_thornley** » Tue Feb 26, 2008 9:08 am

Cool! awesome job

, I like how you've attached halves of the controller. I always prefer horizontal orientation with portables.

From what i can see theres no sound amp or speakers, to be added in the future maybe?

For the battery i'd recomend 4 AA's (5.8-6volts) as your screen uses the same Sharp video processor as the intec/hip gear, witch runs fine at 6v so you should be ok. The radica will run on any thing from 4-9 volts.

You also say that your screen "flickers" on some games. This may be because theres too many 220uf caps on the video line (one on the radica and one on your screen). I had the same problem on the game block (filckering on "bright images" like the sega intro on sonic 2 or 1). But its really quite easy to fix. Theres a 220uf cap in the video area of the radica PCB, on the under side just short the legs together. Heres a pic:

<img src="http://i108.photobucket.com/albums/n19/ ... deoFIX.png" border="0" alt="Photobucket"></a>

Try it see if theres any difference...

Also you could mod the radica for s-video as your screen's Sharp video processor is capable of s-video.

Let us know how you get on...

nubie · Post by **nubie** » Tue Feb 26, 2008 3:51 pm

sam_thornley wrote:Cool! awesome job , I like how you've attached halves of the controller. I always prefer horizontal orientation with portables.

Yeah, I like horizontal, and this screen is pretty big actually, all 5 inches of it.

From what i can see theres no sound amp or speakers, to be added in the future maybe?

Yep, I put the right side of the controller completely covering the sound and bright wheels, and both headphone sockets

, so I need to cut down or relocate the sound board, I already freed the bright knob and moved it to the vents at the top of the screen.

For the battery i'd recomend 4 AA's (5.8-6volts) as your screen uses the same Sharp video processor as the intec/hip gear, witch runs fine at 6v so you should be ok. The radica will run on any thing from 4-9 volts.

I am using NiMH, on the AAA and AA packs I get 5.25 volts fresh charged, and 4.98 as they settle in, I have to use rechargeables, so I am just going to get used to it or use 6 cells. (although as long as I am putting out close to 5 volts I am considering bypassing the voltage regs on the LCD and Radica, I just need a circuit that will make +12v and -12v to drive the LCD)

You also say that your screen "flickers" on some games. This may be because theres too many 220uf caps on the video line (one on the radica and one on your screen). I had the same problem on the game block (filckering on "bright images" like the sega intro on sonic 2 or 1). But its really quite easy to fix. Theres a 220uf cap in the video area of the radica PCB, on the under side just short the legs together. Heres a pic:

snip

Also you could mod the radica for s-video as your screen's Sharp video processor is capable of s-video.

Let us know how you get on...

I do want S-Video (Sonic 2 bleeds blue like a dying alien), but I can't find a picture of the mod, have you got one?

I will try bypassing that capacitor to clean up the signal (If I go S-Video should I bypass the amp too? I won't put an amp on the Luma line so why should there be one on the Chroma line? I plan to run dual shielded lines about 5-6 inches.)

Nuts, I just went to town and forgot to pick up some new caps (10uf 25v) to replace the three I layed down flat

, oh well, maybe I will remember the next time I go, in a month

.

This project was because I was sick and wanted to see what I could build for $8 (the cost of the radica) using the junk laying around in my room. While I wait for my PC parts to come in (how does 95945 look even remotely like 91311?? Neither are even my confirmed Paypal ship too address

.)

EDIT: Sound is almost in, it will be pretty nice.

nightwheel · Post by **nightwheel** » Tue Feb 26, 2008 8:01 pm

Are you going to do a cart mod on this thing?

Anyways, this is looking quite good. I like that you chose the franken-case this portable.

nubie · Post by **nubie** » Wed Feb 27, 2008 3:01 am

nightwheel wrote:Are you going to do a cart mod on this thing?

I am thinking about it, I don't see how to do it in this current case though.

[qoute]Anyways, this is looking quite good. I like that you chose the franken-case this portable.[/quote]

I just grabbed my mini-hacksaw and started sawing, that is always a good sign a project will do well

. I just hope I can do a nicer one at some point. Perhaps modding it to Stereo and S-Video will help. I am officially addicted to Columns.

The sound is in, right now it is just mono, I seriously cut up the Audiovox amp: First I cut the input and headphones off the board, then I cut the volume wheel off and drilled some holes to solder on the wire. I really love my micro drill bits, this is the first I get to use them in a hacking project.

Just so you can see how small this amp is now:

The volume wheel came out a little raw, but I really don't think it matters.

I tried shading (drawing on the top and sides with a pencil) the resistor to bring up the level of that sound that sonic makes as he jumps, I can get it a bit louder with a lot of shading, so I guess I should just solder a resister in there to help it along some more. I wonder why the wrong value resistor was used in the first place? Maybe the resistors got switched on the sound channels to make it "louder" without changing the BOM at the factory

, hmm.

nubie · Post by **nubie** » Sun Mar 02, 2008 2:47 pm

Update Revision 2:

Revision 1.5 was cutting off the "wings", I realized they were preventing a natural cradling in the palm and giving me hand cramps.

This revision moved the controls up, now the corner of the screen rests in my palm fairly naturally (It is sooo comfortable), and it starts looking more like a Game Gear/Nomad/GP32/GP2X.

I think I have settled on 4-6 AA's on the face under the screen, I just need to re-wire the backlight for 7.2volts and maybe add 2 more LEDs (I think I will save that for a rainy day, I need to change my control arm bushings on the car.)

I have some tact switches from an old copier (like 40 at least), so I need to add the "menu" button back.

Bibin · Post by **Bibin** » Sun Mar 02, 2008 9:42 pm

nubie wrote:I tried shading (drawing on the top and sides with a pencil) the resistor to bring up the level of that sound that sonic makes as he jumps, I can get it a bit louder with a lot of shading, so I guess I should just solder a resister in there to help it along some more. I wonder why the wrong value resistor was used in the first place? Maybe the resistors got switched on the sound channels to make it "louder" without changing the BOM at the factory , hmm.

Could we get some more information on that? I've always been annoyed that the PSG channels are nearly inaudable on the radica while the Yamaha channels were overdriven. Could we get some pictures as to where and how you did this?

nubie · Post by **nubie** » Sun Mar 02, 2008 11:13 pm

Bibin wrote:
nubie wrote:I tried shading (drawing on the top and sides with a pencil) the resistor to bring up the level of that sound that sonic makes as he jumps, I can get it a bit louder with a lot of shading, so I guess I should just solder a resister in there to help it along some more. I wonder why the wrong value resistor was used in the first place? Maybe the resistors got switched on the sound channels to make it "louder" without changing the BOM at the factory , hmm.
Could we get some more information on that? I've always been annoyed that the PSG channels are nearly inaudable on the radica while the Yamaha channels were overdriven. Could we get some pictures as to where and how you did this?

These 4 SMD resistors are for the sound channels, you can see that the ones I drew on with a pencil look black on top:

The full size is here (click on "download" to get full quality) http://picasaweb.google.com/nubie07/Por ... 8625404674

I need to double check the audio mod instructions to make sure I got the correct channels.

Edit: I need to check these with a multi-meter to see what is really going on. I will look around for my potentiometer and see if I can get a good clear sound of jumping in Sonic 2, then I can measure it and give you a resistor value.

sam_thornley · Post by **sam_thornley** » Wed Mar 05, 2008 1:30 pm

The stock sound op-amp on the radica is really the best it can do. Its been poorly designed, with some of the channels over driven causing distortion.

I would recomend adding four variable resistors in place of the stock ones. Two 50k for the Yamaha channels and the other two 20k for the PSG channels. Then you can set the volumes to your needs, lowering the yamaha channels i bit so you can hear sonic jump agian.

I built an external op-amp and changed the vaules of some of the components so that the sound was a bit clearer and in stereo.

nubie · Post by **nubie** » Sun Mar 09, 2008 1:45 am

I know, I saw yours. I want to make it simple and sweet (and cheap).

I noticed the sound on the others was way too loud, that means I need to remove them and add a larger value resistor.

I just thought it would be nice if there could be a simple small fix, and cheaper than all those trimpots (Radio shack is too expensive, and the parts houses charge "handling" that adds up to too much as well.)

Maybe I can find some different value SMD resistors, or maybe swapping the resistors around will fix it.

project_failure · Post by **project_failure** » Tue Mar 11, 2008 12:13 am

Nice job I really like it. Hope to see more from you in the future.

sam_thornley · Post by **sam_thornley** » Tue Mar 11, 2008 7:53 am

I've made this quick diagram up on how to convert a radica to output S-video. (As segasonicfan's original schematic image has gone dead, like you said).

Its quite simple, remove that smd cap that carries chroma signal to the video amp. So then chroma is not mixed with the luma singnal making composite. Then take you chroma line as shown in the image below.

<img src="http://i108.photobucket.com/albums/n19/ ... svideo.jpg" border="0" alt="Radica s-video! shame it does'nt do RGB..."></a>

This way works fine for me. I'm using it on my game block and in a new un-named project. Gives about 30-50% increase of quality over composite (depending on what screen you use). Though if you get a bit of cross color add a 220uf 10-25v capacitor on the chroma line, this should help (it does for me

)