Need Help on Flash Cable

[twilight99]

I am building a flash cable using 74HC14 using a schematic (based on Dr. Bizar's circuitry) posted on this forum. I want to use this on 3310. Questions:
1. Where is Vpp located on the phone? Or do i need to use an external power supply?
2. If external supply, what is the volatge?
3. where is B-Temp loacted on the phone?

Appreciate help on this one....thanks.

[danwood76]

Btemp is not used on the 3310 and the Vpp doesnt need to be used either
It all depends what sort of connector you have for your phone

If it is one that clips under the battery then all you need is the Mbus, Fbus Rx, Fbus Tx & Gnd

regards,
Danny

[twilight99]

thanks danny...i just have a basic electronics background, and i hope you won't mind me asking a few more questions.

i found this circuitry posted on this site: http://nokiafree.org/forums/attachment.php?attachmentid=12198&stc=1
i don't remember the forum where I found it so i'll just post these questions to you:

1. The capacitor is labeld '100N'," is this meant to be 100 nanofarad?
2. A resistor is labeled '4K7,' is this meant to be 47Kohms?
3. Another resister is labeled "100R,' is this meant to be 100kohms?
4. Can i put a 3.8V zener diode across the Vpp?

thanks again,

kurt

[danwood76]

1. The capacitor is labeld '100N'," is this meant to be 100 nanofarad?

Yes



2. A resistor is labeled '4K7,' is this meant to be 47Kohms?

No
Where the K is is the decimal point so this one is 4.7kohms
A 1k5 is 1.5 kohms etc



3. Another resister is labeled "100R,' is this meant to be 100kohms?

No
100R is 100 ohms



4. Can i put a 3.8V zener diode across the Vpp?

Why would you put a zener there?
Maybe I missed what you meant

That scheme looks good and should work well

regards,
Danny

[twilight99]

Thanks for your approval on the circuit -- I have bought all the components and ready to bread-board it. The reason I asked about the zener is that Dr Bizar's circuit have it (I think it may be for protection); please refer to: http://www.xored.dk/nokia/schematic/bizar_3in1.pdf

I'm also concerned if it is ok to plug both DB9 and DB25 at the same time on the computer, and then use the switch to select Mbus/Flash function on the original circuitry (or let software select on Dr Bizar's circuit)? This way, I don't need to plug/unplug the connectors...

Again, appreciate your advice.

[ldicdican]

Thanks for your approval on the circuit -- I have bought all the components and ready to bread-board it. The reason I asked about the zener is that Dr Bizar's circuit have it (I think it may be for protection); please refer to: http://www.xored.dk/nokia/schematic/bizar_3in1.pdf

I'm also concerned if it is ok to plug both DB9 and DB25 at the same time on the computer, and then use the switch to select Mbus/Flash function on the original circuitry (or let software select on Dr Bizar's circuit)? This way, I don't need to plug/unplug the connectors...

Again, appreciate your advice.

your posted schematics of combined flasher/mbus seems to work ok!
but about your question regarding you want to PLUG BOTH DB9 and DB25 at the same time, YES, YOU SHOULD!

why?
well, as your schematics show that the 74HC14 chip gets its supply voltage from LPT's(DB25) pin #'s 3 and 5, if you are going to use the MBUS mode, the DB9 won't power-up this 74HC14 preventing you to use the MBUS function....

i don't know if all the time DB25's pin 3&5 has output voltage to supply the chip :(
or it will only toggle once your Nokia Flasher software is executed.

to be sure of it, that your chip is powered, add a signal diode(IN4148) to pin 4 and pin 7 of DB9, and connect it's anode together, connect a zener(3.3-5.1v) diode from that point and gnd(pin 5), then that will supply the chip's(pin #14 of i.c.) Vcc accordingly.

best regards!

[danwood76]

The power always comes out from those two pins on the DB25
Dr bizars flasher (2 in 1) is what I used to use and that uses power from the DB25 all the time you use weather in flash or Mbus mode

regards and good luck,
Danny

[ldicdican]

The power always comes out from those two pins on the DB25
Dr bizars flasher (2 in 1) is what I used to use and that uses power from the DB25 all the time you use weather in flash or Mbus mode

regards and good luck,
Danny

thanks Danny for clearing this up... :)
i've got to modify my combined flasher/mbus cable....

best regards!

[twilight99]

thanks, danny..,and to idicdican too...now if only i can find the proper substitute for the MPF970 PFET, which is not available here....

[loziognappo]

This is PCB made by me! :)

Bye.

[twilight99]

thanks for posting...

i've been reviewing the schematics and narrowed down my choices to these:

1. Combined flasher/mbus cable with manual selector
http://nokiafree.org/forums/attachment.php?attachmentid=12198&stc=1

2. Dr Bizar Combi Flasher/Mbus Cable (2-in-1), software selection
http://www.xored.dk/nokia/schematic/bizarcombi.pdf

3. Dr Bizer Combi Flasher/Fbus/Mbus Cable (3-in-1), software selection
http://www.xored.dk/nokia/schematic/bizar_3in1.pdf

The 3-in-1 looks great, but requires the use of P-channel JFET (MPF970 or equivalent J174, J176 and J177). This PFET is not available in my country, so i'll try other PFETs with similar specs. Any suggestions for the right PFET substitute will be appreciated...

[ldicdican]

@twilight99,

i tried your posted flasher/mbus cable with manual selector as you numbered it #1 on your previous post, it didn't work for me the MBUS protocol, i just added an NPN transistor in place of inverter's pin 10-13....

pm me if you need my schematics using NPN transistor on MBUS part! :-)

[twilight99]

I'd like to have the revised schematic. Have you tried testing the other two circuits which uses software to switch between MBBUS/FLASH?

[ldicdican]

here is my combined flasher and mbus with manual switching!

http://img.photobucket.com/albums/v116/ldicdican/combiflasher.gif

[danwood76]

Note:

LEDs in scheme are the wrong way round :)

regards,
Danny

[twilight99]

Can the circuit posted by idicdican be modified so as to have MBUS/FBUS switching via software instead of a toggle switch? Any idea? Or should i stick to bizar's 2-in-1 and 3-in-1 combi cables with software switching?

[ldicdican]

Can the circuit posted by idicdican be modified so as to have MBUS/FBUS switching via software instead of a toggle switch? Any idea? Or should i stick to bizar's 2-in-1 and 3-in-1 combi cables with software switching?

nope! it has to be manually switched...
also, that schematics is "FLASHER and MBUS" protocols AND NOT "MBUS and FBUS"...

[twilight99]

nope! it has to be manually switched...
also, that schematics is "FLASHER and MBUS" protocols AND NOT "MBUS and FBUS"...

yes you're right...i got the terms mixed up..should've been "flasher/mbus" . think i'll try the two software-switched 2-in-1 and 3-in-1 combi...