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OG Xbox Forums => Hardware Forums => General Hardware/Technical Chat => Topic started by: animex2 on January 20, 2004, 04:20:00 PM

Title: Cheap Lpc Question
Post by: animex2 on January 20, 2004, 04:20:00 PM

Im going to be connectiong the + Wire to the 3.3 Volt. and the - wire to the ground, But on this diagram -



The 5.0v is being used also, But i was reading somewhre that using a battery, this is not needed?

Any info on that?

Title: Cheap Lpc Question
Post by: veg on January 20, 2004, 07:27:00 PM

Correct - if you use batteries you will not need the 5v. I don't see a need for the 5v either way. The SST chip uses 3.3 for power and programming purposes. That diagram has you using the xbox LPC header itself for energy source. I would check the schematic that uses the regulator. Pin 3 of the regulator is the 5v Vin from the usb port. This is the only place where you would want 5v.

Personally I would use a regulator...but that's me.

Title: Cheap Lpc Question
Post by: networkBoy on January 20, 2004, 08:12:00 PM

if you are going to use batteries use FRESH AA cells (2 in series)
-nB

Title: Cheap Lpc Question
Post by: animex2 on January 21, 2004, 12:00:00 PM

alright, cool, what would the regulator be for? USB Power?

Title: Cheap Lpc Question
Post by: networkBoy on January 22, 2004, 10:38:00 AM

yup

Title: Cheap Lpc Question
Post by: animex2 on January 22, 2004, 12:28:00 PM

how could i obtain the regulator / what does it look like?

Title: Cheap Lpc Question
Post by: networkBoy on January 22, 2004, 06:43:00 PM

it's an LM317T and a couple of resistors.  Possibly radio shack.
-nB

Title: Cheap Lpc Question
Post by: animex2 on January 25, 2004, 02:33:00 PM

http://www.radioshac.....t_id=276-1778 from radio shack

With an 100 ohm resistor it would take the 5v to 3v, would it work with that and a 100 ohm resistor or what?

Title: Cheap Lpc Question
Post by: nleahcim on January 25, 2004, 05:55:00 PM

QUOTE (animex2 @ Jan 21 2004, 02:20 AM)

(IMG:http://pictures.xbox-scene.com/3/lpc-diag/lpc.jpg) Im going to be connectiong the + Wire to the 3.3 Volt. and the - wire to the ground, But on this diagram - (IMG:http://warmcat.com/milksop/cheaplpc-sch.png) The 5.0v is being used also, But i was reading somewhre that using a battery, this is not needed? Any info on that?

what exactly does this circuit do?

Title: Cheap Lpc Question
Post by: animex2 on January 26, 2004, 02:47:00 AM

make a cheap LPC programmer that uses the power from the xbox LPC (wich i find rather stupid, beacuse my xbox is sorta far away from my comp and im not buying a 20 foot paralel cable)

Title: Cheap Lpc Question
Post by: animex2 on February 10, 2004, 04:03:00 PM

QUOTE

http://www.radioshack.com/product.asp?cata...t%5Fid=276-1778 from radio shack With an 100 ohm resistor it would take the 5v to 3v, would it work with that and a 100 ohm resistor or what?

ya, bump that question =P

Title: Cheap Lpc Question
Post by: greengiant on February 11, 2004, 12:13:00 AM

Try out this version:
http://cheaplpc.com/...ipboard-new.png

I made it after building a HUGE bunch of breadboard CheapLPC's. Little by little I optimized the design.

Title: Cheap Lpc Question
Post by: animex2 on February 11, 2004, 02:46:00 PM

Yea, i was going to use that Diagram i saw, but i cant make out what the little brown circle and such are x.x

Title: Cheap Lpc Question
Post by: networkBoy on February 11, 2004, 03:17:00 PM

QUOTE (animex2 @ Feb 11 2004, 01:27 AM)

QUOTE http://www.radioshack.com/product.asp?cata...t%5Fid=276-1778 from radio shack With an 100 ohm resistor it would take the 5v to 3v, would it work with that and a 100 ohm resistor or what? ya, bump that question =P

this won't work as the resistor in series with the rest of the circuit will only limit the current available, not the voltage.  You need to use a voltage regulator.
-nB

Title: Cheap Lpc Question
Post by: greengiant on February 11, 2004, 05:43:00 PM

Be more specific.  Usually a black dot means that its making contact.

The components are on the main cheaplpc website.

Title: Cheap Lpc Question
Post by: hippo on February 12, 2004, 02:37:00 AM

2 diodes will drop it and so will a LED after the forward voltage of 1.7 for red. Best bet is the strip board version and usb power. Radio shack only has voltage regulators down to 5v last I checked.

Title: Cheap Lpc Question
Post by: animex2 on February 12, 2004, 04:12:00 AM

I dont get what the things i circled are, the orange, grey and orange thing...

Title: Cheap Lpc Question
Post by: networkBoy on February 12, 2004, 04:47:00 AM

QUOTE (hippo @ Feb 12 2004, 12:37 PM)

2 diodes will drop it and so will a LED after the forward voltage of 1.7 for red. Best bet is the strip board version and usb power. Radio shack only has voltage regulators down to 5v last I checked.

They do have LM317T's which are adjustable down to 1.2 volts.

QUOTE

I dont get what the things i circled are, the orange, grey and orange thing...

the purple and orange thing are capacitors to smooth any ripple present and to provide stability in the regulator (grey) this is common (and good) design practice.

Title: Cheap Lpc Question
Post by: animex2 on February 12, 2004, 07:48:00 PM

so i need to get 2x volt capasitators (different number for x im assuming) and a LM317T? what would the X be for each one? (orange and purple)

Title: Cheap Lpc Question
Post by: networkBoy on February 12, 2004, 08:22:00 PM

generally you would use a 1µF (micro-farad) 16V cap where the purple one was and a .1µF monolithic cap for the orange one.  You should be able to get these darn near anywhere.  If not you have my e-mail, cover postage and paypal fees and I'll hook you up (only prob there is that the mail is so much slower than running out to radio shack)
-nB

Title: Cheap Lpc Question
Post by: animex2 on February 13, 2004, 06:33:00 AM

now, if anyone can make anything from that Diagram i modifyed, does that look right?

assuming all the lines are insulated wire and such...

also, ignore the part at the bottem that says socket....

Title: Cheap Lpc Question
Post by: networkBoy on February 13, 2004, 09:50:00 AM

anyway I'll make up a schematic over the holiday weekend and post it both here and on my site.
-nB

Title: Cheap Lpc Question
Post by: animex2 on February 13, 2004, 11:55:00 AM

QUOTE (animex2 @ Feb 13 2004, 04:33 PM)

now, if anyone can make anything from that Diagram i modifyed, does that look right? assuming all the lines are insulated wire and such... also, ignore the part at the bottem that says socket....

ya, i updated the picture if its easier to understand...

Title: Cheap Lpc Question
Post by: networkBoy on February 13, 2004, 01:10:00 PM

I know what parts these are but I still cant make out your connextions.... Also which CAP is which?  Schematic up by tonight (maybe late)
-nB

Title: Cheap Lpc Question
Post by: animex2 on February 13, 2004, 03:21:00 PM

I just ran out to Radio Shack... They didnt have Exactly what you said.... But im hoping this will do...

I got the LM317T (lucky me, the last one they had)
a 0.1µF Ceramic Capacitor (50WVDC Max)
and 1.0µF Tantalim Capacitor (35WVDC Max)

will those work?

and on the schematic i made.... The one on the top is the 0.1.µF, the middle is the LM317T, and the bottem is 1µF

Title: Cheap Lpc Question
Post by: greengiant on February 13, 2004, 03:28:00 PM

Alright, those are 2 capacitors and 1 voltage regulator.

I dont know WHY ppl have been suggesting the LM317T, thats a variable voltage regulator, where you need extra resistors to select the output voltage. WASTE.

You just need 1 3.3v Regulator, a common part number is 78l033


The parts you asked about..
1 - 0.1uf Ceramic Capacitor (Stabilizing output)
1 - 10uf Polarized Radial Capacitor (Stabalizing input)
1 - ZR78L033

Good Luck.

Title: Cheap Lpc Question
Post by: animex2 on February 13, 2004, 03:37:00 PM

so using the LM317R, 0.1uf Ceramic cap, and 1.0uf Tantalum Cap will not work?

If not, will it work with the right kind of resistors?

If so, what ohm resistors?

btw

i searched google for ZR78L033 and 78l033 but didnt find anything or any place i could buy them....

Title: Cheap Lpc Question
Post by: networkBoy on February 13, 2004, 07:17:00 PM

your missing 2 components ( a pairt of resistors) if I forgot to tell you that, then my bad.  I'm feeling quite under the weather at the moment so the schematic I promised will be up tommorow (hopefully).
-nB

Title: Cheap Lpc Question
Post by: animex2 on February 14, 2004, 03:28:00 AM

by any chance do you know what ohm resistors?

::EDIT::

BTW NB....

Im assuming 1uf (35WVCD) Tantalum Capacitor and 0.1uf (50WVDC)Ceramic Capacitor are acceptible to use?

Title: Cheap Lpc Question
Post by: networkBoy on February 14, 2004, 08:25:00 AM

caps are fine. and here is the schematic:


The caps are as you already have (100nF is .1 µF) the resistors are:
R1 = 240 OHMS
R2 = 400 OHMS

sorry about the lag in answering.
-nB

Title: Cheap Lpc Question
Post by: networkBoy on February 14, 2004, 08:33:00 AM

QUOTE (greengiant @ Feb 14 2004, 01:28 AM)

Alright, those are 2 capacitors and 1 voltage regulator. I dont know WHY ppl have been suggesting the LM317T, thats a variable voltage regulator, where you need extra resistors to select the output voltage. WASTE. You just need 1 3.3v Regulator, a common part number is 78l033

that's fine when you can find the parts, but these are not as common as the 317's.
More parts, yes, but also available everywhere.
-nB

Title: Cheap Lpc Question
Post by: animex2 on February 14, 2004, 09:30:00 AM

the closest numbers i could find at radio shack for the numbers you want are -

220 ohm 1/4W 5% Carbon Film (240 you wanted, 20 to low)

and

330 ohm 1/4W 5% Carbon Film (400 you wanted, 70 to low)

or

470 ohm 1/4W 5% Carbon Film (400 you wanted, 70 to high)

=/

Title: Cheap Lpc Question
Post by: networkBoy on February 14, 2004, 09:37:00 AM

use the 220 ohm, that's fine, but buy their 5 pack of 10 resistors and place 4 in series with the 330 ohm (thus making it 370 ohm)
That will get you 3.35 volts out which should be fine.
-nB

Title: Cheap Lpc Question
Post by: animex2 on February 14, 2004, 09:50:00 AM

5 pack of 10 ohm resistors?

::EDIT::

if thats so, i know i have at least 4 100 Ohm resistors.... I could link them up in a series making it 400 ohms...

and this may be pushing it... but i should have at least 6 100 ohm resistors....

2x 100 == 200 ohm for R1 (40 to low... if this is too low i can just get the 220s)
4x 100 == 400 ohm for R2

Title: Cheap Lpc Question
Post by: animex2 on February 14, 2004, 10:07:00 AM

QUOTE (networkBoy @ Feb 14 2004, 06:25 PM)

caps are fine. and here is the schematic: The caps are as you already have (100nF is .1 µF) the resistors are: R1 = 240 OHMS R2 = 400 OHMS sorry about the lag in answering. -nB

ok....

So the 5v should go to pin 6 on the programmer.... 3.3v should go to pin 9... and the 0v should go to pin 2?

Also... Where does USB Pin 1 and 4 come into play? x.x

Title: Cheap Lpc Question
Post by: networkBoy on February 14, 2004, 12:39:00 PM

400 and 220 ohm would work out to 3.52 volts, which is too high.
200 ohms would be enven higher
-nB

Title: Cheap Lpc Question
Post by: animex2 on February 14, 2004, 01:37:00 PM

so i want 400 (4x100) and 240 on the dot... (1x 220 + 2x 10)

that would work out good, right?

::EDIT::



Is that right?

Title: Cheap Lpc Question
Post by: networkBoy on February 14, 2004, 09:45:00 PM

QUOTE (animex2 @ Feb 14 2004, 11:37 PM)

so i want 400 (4x100) and 240 on the dot... (1x 220 + 2x 10) that would work out good, right? ::EDIT:: Is that right?

yes you want those values on the dot.  as to the pin outs I am not at my comp at the moment so I'm not sure....
-nB

Title: Cheap Lpc Question
Post by: greengiant on February 15, 2004, 12:18:00 AM

The 3.3v regulators are as common as the lm317, actually more because they are more used.

I forget who is actually building this circuit now, but your only complicating yourself.

There are variouse companies that make the voltage regulators, ZR is a common one, but there are others.
ZR - http://www.zetex.com/3.0/pdf/zr78l.pdf


Simple search on yahoo,
http://search.yahoo....n=20&fl=0&x=wrt

Reveals parts from NS, TPS LT, and MANY other companies. Digikey has some 12 to choose from for example.


Saves you the hassle of the wiring up the extra resisotrs for the Lm317, as well it saves you the trouble of finding the exact values.
With the SST you cannot provide more than the specs (you can upto 3.5 even 3.7 at low current) or else you kill the chip, if you go lower than 3.2 the chipp will give you erraditc responses.

Title: Cheap Lpc Question
Post by: animex2 on February 15, 2004, 03:36:00 AM

QUOTE (animex2 @ Jan 21 2004, 02:20 AM)

so

in the diagram i have quoted the 0v is pin 2, and the 3.3v is pin 9, so im assuming i was correct before?

Title: Cheap Lpc Question
Post by: networkBoy on February 15, 2004, 08:31:00 AM

yup
-nB

Title: Cheap Lpc Question
Post by: animex2 on February 15, 2004, 10:23:00 AM

alright, thanks for your help NB and Green Giant and everyone else =)

Ill be building this Tuesday and hope it works, Lmao...

Title: Cheap Lpc Question
Post by: animex2 on February 15, 2004, 10:30:00 AM

er, one last quesiton, how do i know what is pin 1 and 3 on the LM317T? (obviously the middle is 2) should I be looking at the metal part at the top or the plastic part?

Title: Cheap Lpc Question
Post by: greengiant on March 14, 2004, 02:43:00 AM

Well, the very first 5 units I made I used the LM317 cause I didnt know better.
I made a diagram, long time ago, which I was trying to find for you. Found it, So here it is.





Also, for the pins. Its standard, usually.

You will need to check the datasheet. I have encountered 2 types of LM317 where 1 has   Vin GND Vout, and the other is Vout gnd Vin.   When looking at the flat side.


Heres some VERY useful links for the LM317.
http://www.qsl.net/ok1duo/lm317.htm  <- Schematic + Resistor value calculator for it.

http://casemods.poin...rn.org/vregtut/  - A tut on how to build a Vreg for fans, using the LM317

http://members.aol.c...aysaver/p3.html - For some playstation hacking thingy, but they use the LM317. Middle of the page has some 5 pictures of the variouse chips, and the pin outs. (Theres the LM317LZ, LM317T) LZ is the more common, lower voltage version.


Well have fun with your project.

Title: Cheap Lpc Question
Post by: thedustycelt on April 05, 2004, 09:40:00 AM

I was reading thtough this post because I am building the same thing, and I have a Question...
Why do we need to use the voltage regulator and capacitors?
Can't we just use a voltage divider circuit?

two resistors, and bam! We are done. (a lot cheaper than the voltage regulator) Using a 10ohm and 20 ohm resistor would bring the 5 volts down to 3.3.
Is there a reason why this shouldn't work?

Info and calculator borrowed from:
http://hyperphysics..../voldiv.html#c1

Title: Cheap Lpc Question
Post by: hippo on April 06, 2004, 01:59:00 AM

You could use the south end of a red LED at 5v 220 ohms should leave 3.3 volts after the forward voltage of 1.7v or simply use 2 diodes in series to drop 5v to 3.6 or so. IMHO a regulator is just alot of extra work.