USB SPI Flasher with PIC18F2455 - now with source and binaries

[threesixtyuser]

Have I misread the USB socket pinout?

From the datasheet - http://www.farnell.com/datasheets/29091.pdf it looks to me like pin1 is top left and then it goes clockwise and pins 1 and 2 are the rear board pins and 3 and 4 the front ones.

Nope, faulty datasheet! I used the same Lumberg socket and it simply doesn't match the USB standard. Just google for "usb b" pinout and you'll find this one is wrong.

I measured the pins because pin number weren't mentioned in the PCB layout of the datasheet either and came out with the following pinout (seen from te top) for the circuit board/socket:

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

[doveman]

Thanks. It won't take much re-arranging to correct for that.

[bigfish58]

Can anyone confirm this is right before I go ahead and build it;



Thanks

[Arakon]

Pin 26 goes to GND on the chip, pin 27 doesn't have any connection after the resistor.

[bigfish58]

Oops

Switched them round Thanks

[bigfish58]

The final PCB;



Hopefully should get this made tomorrow

[SpikedCola]

If you relocate the parts and add a ground plane, you can make the entire board single-sided, with no jumpers

[doveman]

I just realised there's a couple of mistakes in my layout.

Most importantly, I hadn't connected pin 19 to anything  I also don't need that diagonal lead to the - of C3 as I can just join the long vertical lead to the GND of the jumper. Sorry for the sloppy edits, but I was only using a demo of LochMaster, so I couldn't save and my PC crashed!

[doveman]

bigfish58, what 8x8 connecter and lead are you using as that would make my layout somewhat tidier?

[bigfish58]

I'm using a 8x8 pin Header.

Btw, I'm using some software called PCB Wizard - good for this kinda thing

It also converts it to a PCB for you

[doveman]

Cheers for the tip but I don't design enough to justify the price.

I think I'm going to stick with the 5x5 headers and 10-core cable. The 8x8 and 16-core are quite a bit more expensive and I'm not sure there's room to mount the 8x8 connector on the Xbox.

[bigfish58]

Who says we have to buy it 

[Arakon]

Who says we'll tolerate piracy discussions?
First and only warning.

[doveman]

Is there a maximum recommended length for the LPT cable to the ART2003 programmer? I'm re-using the lead I was using for flashing the NAND, which worked most of the time (had to re-dump the odd block, but then there was the additional wiring inside the Xbox), so should that be OK?

[chaoz2]

just a final note on pin 20 and pin 14 capacitors value


the creator of art2003 programmer also made an usb programmer using pic18f2550

schematics here http://www.foxdelta.com/products/programmer/upp/fd-upp-schematic.jpg

part list here http://www.foxdelta.com/products/programmer/upp/usbprogrammer-kit.pdf

firmware here http://www.vu2fd.com/software/FD-UPP.zip


he even add leds if can be of help (that busy led is juicy)

i am not too good to read schemes in detail, but someone hopefully can do it!


(i see 10uf for pin 20 and 100nf for decoupling and 0,4uf for pin 14 but i can be mistaken)

[maximilian0017]

Ok, lets settle this 

Latest Pic datasheet
--------------------------
17.2.2.8 Internal Regulator
An external 220 nF (±20%) capacitor is required for stability.

TABLE 28-5:USB INTERNAL VOLTAGE REGULATOR SPECIFICATIONS
Min 0.22 μF
Typ 0.47 μF
Max 12(2) μF Ceramic or other low-ESR capacitor recommended

2: This is a recommended maximum for start-up time and in-rush considerations. When the USB regulator is
disabled, there is no maximum.
--------------------------

Ok 220nF seems to be the minimum, but 0.47 μF is typical and should this be the best option, agreed?
( higher as 0.22 μF would probably be used id the Vusb was used for something.)

100nF is standard for decoupling per ic but i would ad a larger capacitor for the complete circuit. Would it be better to add two independant capacitors or would one larger one be enough?

[SpikedCola]

Correct, 0.47uF is *the* proper value.

[geep6]

here is the one im making here is the eagle cad file    http://www.filefactory.com/f/bb3892e1da3ae838/        

[threesixtyuser]

Ok, lets settle this  

Latest Pic datasheet
--------------------------
17.2.2.8 Internal Regulator
An external 220 nF (±20%) capacitor is required for stability.

TABLE 28-5:USB INTERNAL VOLTAGE REGULATOR SPECIFICATIONS
Min 0.22 μF
Typ 0.47 μF
Max 12(2) μF Ceramic or other low-ESR capacitor recommended

2: This is a recommended maximum for start-up time and in-rush considerations. When the USB regulator is
disabled, there is no maximum.
--------------------------

Ok 220nF seems to be the minimum, but 0.47 μF is typical and should this be the best option, agreed?
( higher as 0.22 μF would probably be used id the Vusb was used for something.)

100nF is standard for decoupling per ic but i would ad a larger capacitor for the complete circuit. Would it be better to add two independant capacitors or would one larger one be enough?

So shortly this means that the ideal conclusion for this circuit ends up in:

Crystal Cap (COG/NPO): (2x C_crystal) - PIC's C_osc2

Cap on pin 14 (X7R/X8R): 470nf/0,47μF (or within a range of 0,22μF - 12μF)
Cap on pin 19/20 (X7R/X8R): 100nF/0,1μF (or within a range of 0,1μF - 10μF)

COG/NPO and X7R/X8R because X5V X7S Z5U and Y5V have too much capacitance change over temp (this doesn't mean they won't work)

Correct me if I'm wrong and I'll correct my post!

[maximilian0017]

So shortly this means that the ideal conclusion for this circuit ends up in:

Looks good,

The only question remaining is the single 10 μF or a 100nF and a 10 μF.