USB SPI Flasher with PIC18F2455 - now with source and binaries

[bulle48]

btw, do you know the answer to: If i use a 12M, 18PF crystal I need 18PF capacitors as well right?

The 2x capacitors that connect to the crystal are considered a series configuration... For 2 caps in series the total capacitance: Ctot= [C1 * C2] / [C1 + C2]... since these caps have the same value (C1=C2=C) then Ctot= C/2...

For a Crystal that needs 18pf load, you should connect 30pf capacitors... this way you have total capacitance of 15pf and allow for 3pf for stray capacitance (capacitance from quartz to package, from lead to uC pin, etc.)

[sandungas]

I understood your formula for capacitors in series bulle48, but i think is easiest the one posted by ColtB45
Capacitance total in series:

Ctot = [C1 * C2] / [C1 + C2]
Ctot = [C * C] / [C + C]
Ctot = [C * C] / [2*C]
2 * C * Ctot = [C * C]
2 * Ctot = [C * C]/C
2 * Ctot = C
Ctot = C/2

In other words... for a crystal with a load capacitance of X.... are needed 2 capacitors of a value around X * 2 ?

And the formula posted by ColtB45 here ---> http://www.xboxhacker.org/index.php?topic=12306.msg92435#msg92435

Capacitors value = (2 * Crystal load capacitance) - 5

Here its been used a "typical" 5nF capacitance for the circuit

The one by coltB45 seems more accurate, but i could not find crystal datasheets with accurate values from the capacitors (mostly has "tips" for all the crystal series and recommends you a "range" not a exactly value)

Btw... the PIC datasheet has some recommended values too (page 28)
4 mhz  ---> 27pF
8 mhz  ---> 22pF
20 mhz ---> 15pF
http://ww1.microchip.com/downloads/en/devicedoc/39632e.pdf



Edit:
Im trying to understand this point with the capacitors now that seems that is almost clarifyed, please correct me if im wrong
There is more info here ---> http://www.sxlist.com/techref/clocks.htm

[threesixtyuser]

thx a lot for all help! will post my results when done building and trying ofcourse!

[APE]

Tried building myself an ART2003 today. Two shorts and smoke later, I got a $10 brick. Bah.

Back to the pcb maker.

[maximilian0017]

Does anyone know if degraded from this post is the latest version? http://www.xboxhacker.net/index.php?topic=8555.msg54509#msg54509

Thats easy, it should say Degraided 1.1B

Ape:
Did the PIC smoke itself?, otherwise you could check for shorts and try it if you get the programmer right.
How did you get the programmer to smoke?, it's all low power 5/3,3v (or did you use an external powersource?)

[threesixtyuser]

On Mac here, so kinda hard to start it up Didn't have time to check it out at home yet.

p.s. Here's my final shopping list:

Incorrect shopping list removed, refer to this post for a (at this moment) correct one

[maximilian0017]

You also need a pcb to build it on.

These connectors are a bit overkill and clumersome for this, just get a single long pinhearder row that you can cut into pieces (7pin and 2/3 pin) and a 7 pin female counterpart.

You should make sure that the wires have a solid core, otherwise you can easely cause a short.

KEKSi:
Take a look at your ground wire, double it up if you are using thin wire, aso make sure there is no resistor in there by accident.
What did you mean with:
only GRD(GND) and VCC wires are copper wires.

[Rescue Toaster]

I have two pretty simple questions...

1) I didn't see this addressed, maybe it is obvious. After attempting the LPT method on my plain old Xenon (never got it reading consistently, always a few errors), I have the two diodes from J1F1 3&4 (by hard drive connector) to 1&2 on J2D2 and then the jumper from J2D2.4 to J2D2.7. Is any of this still needed when using a PIC? Or the old 3x 330 ohm resistors from J1F1 to J2D2? None of that stuff?

2) Does anyone have a part number for a good pin header for J2B1 & J1D2? I saw someone using the same thing as the optical drive power connector, which makes sense. Alternately I'll just solder straight to the board and put the connectors on the PIC board.

Thanks!

[Arakon]

1) once more.. jtag hack and spi reading have NOTHING to do with each other. you ALWAYS need the jtag resistors/diodes for any kind of hack.

[maximilian0017]

A few pages back somebody reorted problems with the pic in SMD format, do any of you have the same problems? (will build a SMD version next and want to be prepaired for trouble)

[Arakon]

I had trouble with the SMD one, but it turned out to be due to the resonator. Rebuilding the circuit from scratch and using a crystal fixed the issues.

[KEKSi]

i have flashed a smd 18f2455 with bootloader over art2003, connected the chip with the usb spi flasher and flashed it again with picflash.
after that the smd 18f2455 was unable to get recognized

it was also not possible to reflash/overwrite the chip with my art2003 programmer
i think it got locked. i was able to read the hole chip.

im still using the same flasher as well as the same art2003 flasher.
everthings works fine with the dil version of 18f2455

[porchmonkey]

I had trouble with the SMD one, but it turned out to be due to the resonator. Rebuilding the circuit from scratch and using a crystal fixed the issues.

could you pls be more specific?

[strygrog]

I built the spi, it worked the first night I built it, but now when I try to use it, it reads up to 0x024 on a 16MB nand, and 0x01C on a 512 mb nand. once it reaches those 2, it gives Error FFFF and then has read errors until its reset. It reaches the same point every time and dies.

I'm using PICFlash v3b plus 2. Windows xp 32bit. nandpro 2b.

The only part I'm not sure if its the right one that I used is the resonator
http://mouser.com/Search/ProductDetail.aspx?R=AWCR-12.00MDvirtualkey52750000virtualkey815-AWCR-12.00MD

Any ideas would be appreciated...

[maximilian0017]

could you pls be more specific?

Look at the modified picture by threesixtyuser

Removed the resonator and replaced it by a crystal and two capacitors.

(Hope you don't mind Arakon)

[maximilian0017]

Any ideas would be appreciated...

Resonator should work but there are reports of trouble, but its better to use a crystal with two capacitors.
Also check out the ground from the pic to the Xbox motherboard(double it if you use thin wire).

[Juvenal1228]

Hey, i built one of these on breadboard using a PIC18F2455 and a 12mhz resonator
burned the pic in winpin800 with an art2003 with the lvp bit selected using the 3b bootloader

now my problem is windows will not detect this as a USB device no matter what i do.

i have a hunch that this is due to frying the pic or part of it with reverse voltage.

at 3:30AM i hooked the usb wires up backwards and put 5V on ground and Gnd on 5V

i can still read and write to the pic in winpic but it will never show on windows, at all.

any ideas?

~Thanks, Juvenal1228

[maximilian0017]

now my problem is windows will not detect this as a USB device no matter what i do.

For usb you need:
USB connector
Resonator/Crystal with right capacitors to ground
220nF on pin 14-GND
All VCC and GNC connections
Capacitor from VCC-GND (if it is electrolitic it is probably scorched after mixup, so replace)

If that all checks out replace the Pic

P.s. if the magic smoke came out of the Pic it is dead, they run on Magic smoke LOL

[cory1492]

Juvenal1228: It's entirely possible you have blown the internal 3.3V regulator or the internal usb transciever while leaving the other devices entirely operational. One quick check is to see if you get 3.3V on the VUSB pin when the pic has 5V power.  If the mcu was burned out, it shouldn't program at all - also do check the rest of the stuff maximilian suggest and be sure you have set the oscillator fuse settings to the right value when programming the bootloader.

P.s. if the magic smoke came out of the Pic it is dead, they run on Magic smoke LOL

[chaoz2]

i would like to share some thoughts after reading some datasheets:

1) as per 18f2455 datasheet when external clock is used capacitive loading is 15pf so i think if you have a 18pf crystal the formula should be 18pf + 18pf = 36pf -15pf = 21pf (so 22pf is almost perfect)

2) as per university study http://hifi.metalabs.org/docs/usbame.pdf 220nf and 100nf capacitors should be 10uf

3) use 5% tolerance resistors or at least 10% not the 20% crap

this is my 2 cents, hope this should be of use