CH341a and logic level converter

[wall]

Hi, I need to flash the bios on a bricked windows tablet, but the chip is 1.8v soic8 and I have no idea how to hookup the 2-channel bi-directional logic level converter, I just know I need a 1.8v reference voltage on the LV side and a 3.3v reference on the HV side.
Any help is appreciated, thank you.

[stj]

Re: CH341a and logic level converter

got any links / foto's?

[wall]

Re: CH341a and logic level converter

The tablet is a Chuwi Hi8 Pro

The usb programmer


The logic level converter

and the soic8 clip

[stj]

Re: CH341a and logic level converter

https://www.sparkfun.com/products/retired/11978
that's the board.
you get the high voltage from the programmer socket, and the low voltage from the chip / tablet.
but i dont think it will work.

most flash chips use bi-directional data pin(s)
what is the part number on the flash?

[wall]

Re: CH341a and logic level converter

You mean the bios chip?
It's a Winbond 25Q64, the rest is scrapped off.

[wall]

Re: CH341a and logic level converter

I have a very old 18650 battery that measures 2.03v, could I use that as the Low Voltage reference? These bios' can take 1.65v to 2.20v if I'm not mistaken.
I don't know which pins need to go through the LLC.

[stj]

Re: CH341a and logic level converter

the reference has nothing to do with it.
those chips use one pin to send data in both directions - that converter wont do that.

how do you know the chip is 1.8v and not 3.3v ?

[meritosari]

Re: CH341a and logic level converter

how do you know the chip is 1.8v and not 3.3v ?

the thing important to note is FW mark after w25q64, that indicate the IC use voltage 1.8v.

experience with ezp2010 didn't kill the ic. maybe just cause corrupted data when transfer process.

that best idea should using converter/adapter for doing flashing bios chips

[stj]

Re: CH341a and logic level converter

3.3 through a 100ohm resistor - maybe with a 2v zener diode to ground,
but NOT with a clip - you will put 3.3v into everything else and trash the cpu.

the chip needs to be removed first.

[wall]

Re: CH341a and logic level converter

The progamming software isn't detecting the programmer I've tried on 3 computers and tried every driver but it just says device state not connected. Shouldn't the PWR led light up?

[stj]

Re: CH341a and logic level converter

what software, what o.s.?

[vinceroger69]

Re: CH341a and logic level converter

Theres a problem with these black versions of these programmers this video may help
https://www.youtube.com/watch?v=5NYe21nFSDI

i have this one in this link not sure if the software works with yours its included in the comments
https://www.youtube.com/watch?v=L0ChYNwunUE

[stj]

Re: CH341a and logic level converter

i have every software version, but i want to know what o.s. he's using.

[vinceroger69]

Re: CH341a and logic level converter

It took me ages to find the bottom one in the link that worked with english language i messaged the poster of that video and he re uploaded the files, in the black version like the tester in this thread i think its a matter of moving the jumper to the correct pins too and then the pc reconises it etc.(although looking at the picture in the thread it does look like its on the correct pins)

[stj]

Re: CH341a and logic level converter

not looking at the video, but i can say the black one can double as a usb>serial convertor if you move the jumpers.

[vinceroger69]

Re: CH341a and logic level converter

some of these gadgets from china work very well once you sort the correct software you can save a lot of cash too as there so cheap.

[stj]

Re: CH341a and logic level converter

yes, i have to have this now!!!!
http://www.ebay.co.uk/itm/291693366485

Core: ARM 32 Cortex-M3 CPU.
72MHz work frequency.
64K flash memory, 20K SRAM.
£1.70!!!

[stj]

Re: CH341a and logic level converter

It took me ages to find the bottom one in the link that worked with english language

the language is selected in the config file.
they all support english

[megaraider]

Re: CH341a and logic level converter

1st. The Winbond chip has to be removed first!
[Otherwise, unless you're an experienced electronic guy you will most likely kill everything connected to the 1.8V power rail]
2nd. Forget the clip and that tricky voltage level converter;
3rd. Use the CH341A programmer and a suitable voltage level converter, e.g. this 1.8V SPI Flash adapter around €4;

[gabiz_ro]

Re: CH341a and logic level converter

I was looking for same thing some time ago.
Never tested,but in near future i'll do one.
http://eximage.ru/image.php?dm=6KNL
http://storage6.static.itmages.ru/i/...50a3837bca.jpg

I recomend second image,since I don't know how programmers are built,but in any case suplimentar resistors will not force IC used in programmer if are direct pin to pin connected with memory needed to program.

Level converter can be use I think.
On SPI chip you have serial data out and serial data in,clock etc.
And all are uni-directional.
Is not like in i2c where you have one pin clock one pin data.
That require bidirectional converter.