[Kindle3] Match up tx/rx pins with tx/rx wires

[Frenko]

Hello folks!

I'm trying repair the k3 I bricked last summer

After quite some time I got hold of a FTDIchip USB cable with a rs232rg chip so that I can access the serial port.

In the cable's manual I found this scheme:

Black -> GND
Orange -> TX
Yellow -> RX

Hence I connected the ORANGE wire with the FIRST pin, the YELLOW with the SECOND and the BLACK with the THIRD. I'm sure the third it's right 'cause it's the ground.

Full of hope I tried to access my kindle using both Hyperterminal (win) and Minicom (linux) but to no avail.

For completeness sake the configuration I used is 115200 baud 8n1 with no flow control.

What am I doing wrong? Should I switch the tx/rx wires? I know I could just try and switch'em and see what happens but I'm not comfortable with this kind of things.

Could you please help?

Thank you

f

[knc1]

Originally Posted by Frenko

Hello folks!

I'm trying repair the k3 I bricked last summer

After quite some time I got hold of a FTDIchip USB cable with a rs232rg chip so that I can access the serial port.

In the cable's manual I found this scheme:

Black -> GND
Orange -> TX
Yellow -> RX

Hence I connected the ORANGE wire with the FIRST pin, the YELLOW with the SECOND and the BLACK with the THIRD. I'm sure the third it's right 'cause it's the ground.

Full of hope I tried to access my kindle using both Hyperterminal (win) and Minicom (linux) but to no avail.

For completeness sake the configuration I used is 115200 baud 8n1 with no flow control.

What am I doing wrong? Should I switch the tx/rx wires? I know I could just try and switch'em and see what happens but I'm not comfortable with this kind of things.

Could you please help?

Thank you

f

Switch them.

If you happen to end up with Rx - Rx
Nothing will happen, they are both inputs

At the same time as having Rx - Rx you will also have Tx - Tx
Nothing will happen, they are both outputs but the devices can tolerate those voltages.

The FTDI, TTL-232Rg-VREG1V8-WE adapter cable can tolerate full ttl levels on its inputs.
I can post the documents if you (or anyone else) wants the references on-line.

And for reference, here is how I did the serial port addition on one of my media players:
http://minimodding.com/tiki-view_blog.php?blogId=8

And if really uncertain -
Connect only the ground and probe with the Rx lead until you see something on the soft terminal screen (after doing the "go online" business of the terminal - then use it as a probe).

[Frenko]

Thanks for your prompt reply!

I'll switch them then.

Just to be sure: with "go on line" business do you mean the "connect" button in hyperterminal... or am I missing something?

[knc1]

Originally Posted by Frenko

Thanks for your prompt reply!

I'll switch them then.

Just to be sure: with "go on line" business do you mean the "connect" button in hyperterminal... or am I missing something?

"connect"
Note, since many of the common terminal emulators are intended to talk to modems they may have an intialization string that they send when you press "connect".

The easy way to deal with that (without changing the terminal's setup) is:
Connect the USB end of cable to computer -
Start the terminal emulator -
Press/Perform "connect" (let it send to the empty end of the cable) -
Now connect the serial end of the cable to the device.

I will start a "Serial Cable" thread RSN to suppliment what has already been posted.

[Frenko]

Thanks

So there's a possibility the wires/pins combination is right already!

Unfortunately there's no empty end of the cable since the wires are directly attached to the pins

It is my intention to make a serial plug anyway and if I succeed I'll put your advice to good use.

If you -or anyone else- has some other hint I'd greatly appreciate it

Cheers

f

[knc1]

Originally Posted by Frenko

Thanks

So there's a possibility the wires/pins combination is right already!

Unfortunately there's no empty end of the cable since the wires are directly attached to the pins

It is my intention to make a serial plug anyway and if I succeed I'll put your advice to good use.

If you -or anyone else- has some other hint I'd greatly appreciate it

Cheers

f

https://www.mobileread.com/forums/sho...3&postcount=23

[Frenko]

Thank you knc1, I really appreciate the effort you put in to help me out.

I switched the cable as you told me but without results: the terminal remained blank before and it remains blank now.

I read the whole thread you started about the serial cable with much interest, even though -due to my scarce command of the English language and the fact that my knowledge in these matters approaches zero- it didn't help me as much as I wished.

Up until now this is the setup I've got:

<- FTDI chip TTL-232Rg-VREG1V8-WE + Kindle 3 wi-fi only

Spoiler:

Building a serial plug proved to be too difficult for me and I'd rather avoid soldering the wires directly on the board in case I decide to send it back to Amazon... although I doubt I ever will

I believe this should be the correct order of wires, which is confirmed if I understand correctly in the other thread.

Also, I double-checked that each wire touches the pin it's supposed to touch and that pin only.

Everything should work at this point... but it doesn't.

Anyone got any idea of what could I have done wrong?

Should I change the terminal setup???

Thanks again.

Cheers,

f

[knc1]

Originally Posted by Frenko

Thank you knc1, I really appreciate the effort you put in to help me out.

I switched the cable as you told me but without results: the terminal remained blank before and it remains blank now.

I read the whole thread you started about the serial cable with much interest, even though -due to my scarce command of the English language and the fact that my knowledge in these matters approaches zero- it didn't help me as much as I wished.

Up until now this is the setup I've got:

<- FTDI chip TTL-232Rg-VREG1V8-WE + Kindle 3 wi-fi only

Spoiler:

I'm using a FTDI chip TTL-232Rg-VREG1V8-WE adapter cable. Building a serial plug proved to be too difficult for me and I'd rather avoid soldering the wires directly on the board in case I decide to send it back to Amazon... although I doubt I ever will

I believe this should be the correct order of wires, which is confirmed if I understand correctly in the other thread.

Also, I double-checked that each wire touches the pin it's supposed to touch and that pin only.

Everything should work at this point... but it doesn't.

Anyone got any idea of what could I have done wrong?

Should I change the terminal setup???

Thanks again.

Cheers,

f

Those contacts are on very small centers, but you write that you are sure they are not touching each other under the cover.
The contact "grasshopper leg" springs in the connector are a bit "rounded" they could cause the inserted wires to "roll off" to one side or the other when the cover is put back in place.

It wouldn't do any harm if they touch each other, but it wouldn't work if they are.

Check the terminal setup, it may be expecting "flow control" - turn that off in the terminal's configuration.

and/or -

Connect the RTS# and CTS# leads together (the Brown and Green ones).
That way the cable driver and terminal will get a "clear to send" signal when it "goes online" (generating the "request to send" signal.

If you can hang around a few more days, I will finish that serial cable thread with directions on how to make a matching connector tab.

[Frenko]

Originally Posted by knc1

Those contacts are on very small centers, but you write that you are sure they are not touching each other under the cover.
The contact "grasshopper leg" springs in the connector are a bit "rounded" they could cause the inserted wires to "roll off" to one side or the other when the cover is put back in place.

It wouldn't do any harm if they touch each other, but it wouldn't work if they are.

I used a tester to see if any pin is shorted with each other and everything seemed fine (it sounds only with "itself") then since I wasn't sure the wires actually touched the contacts I made a little cut in each wire (fairly visible in the full size image) and again everything seemed fine: the wires touch the contacts that touch the pins that are not shorted.

Originally Posted by knc1

Check the terminal setup, it may be expecting "flow control" - turn that off in the terminal's configuration.

115200 bps 8n1 with no flow control. It is my understanding that lowering the speed could only help, anyway I never tried to do so.
In the connection's properties -> settings I didn't change anything:
emulation = auto
telnet id = ANSI
buffer = 500

Originally Posted by knc1

Connect the RTS# and CTS# leads together (the Brown and Green ones).
That way the cable driver and terminal will get a "clear to send" signal when it "goes online" (generating the "request to send" signal.

This is surely the biggest breakthrough I had so far.
Unfortunately it's not reassuring at all.
On the terminal, the line

cat: can't open '/sys/devices/platform/charger/globals': No such file or directory

is repeated several times.
I'll go to sleep and repeat the experiment tomorrow, in the remote eventuality of a different outcome I'll update the thread.
Prior to this I was pretty sure the kindle "worked" because
1) the "power led" is green
and -most importantly-
2) a few days ago I got a "low battery" warning displayed on the screen followed by a frozen boot screen the next morning (better than nothing!)
...but I'm not that sure now.

Originally Posted by knc1

If you can hang around a few more days, I will finish that serial cable thread with directions on how to make a matching connector tab.

I sure can... but I really doubt I'll be able to follow your instructions.

Thanks anyway

Cheers,
f

[knc1]

Originally Posted by Frenko

This is surely the biggest breakthrough I had so far.
Unfortunately it's not reassuring at all.
On the terminal, the line

cat: can't open '/sys/devices/platform/charger/globals': No such file or directory

is repeated several times.
I'll go to sleep and repeat the experiment tomorrow, in the remote eventuality of a different outcome I'll update the thread.

Cheers,
f

That is actually good news.
The device is talking to your terminal now, the serial cable hookup must be correct.

Since I have never (yet) seen what the 'normal' outputs on the serial line are, that may be 'normal' or it may be another problem.
But it is readable text

So at least the terminal can receive characters, it can probably transmit them also.

Note Be careful of using a "continuity tester" to "ring out" these connections. They may well produce a voltage or electrical noise spike that is more than the devices can withstand.
The FTDI cable is documented to withstand 5v (even on the 1.8v model cable) - no telling if the Kindle devices can do that.

[Frenko]

Originally Posted by knc1

That is actually good news.
The device is talking to your terminal now, the serial cable hookup must be correct.

You're right! I have no clue what to do next... but you're right!

I guess I should start a new thread then!
Otherwise...

Originally Posted by knc1

Since I have never (yet) seen what the 'normal' outputs on the serial line are, that may be 'normal' or it may be another problem.

I'm fairly sure this is what the normal output should look like
http://www.youtube.com/watch?v=7OCpJbkGb7M&t=2m11s (video "courtesy of" fellow forumer @Seaniko7 which -I must add- is a very kind man)

the above link cuts to the chase, the embedded video below does not (the relevant part starts at 02:11)

Originally Posted by knc1

Note Be careful of using a "continuity tester" to "ring out" these connections

I'll keep it in mind for the future.
It makes a lot of sense but I thought they wouldn't use a "high" voltage for a tester... anyway I hope that from the error I got I can reasonably infer that I didn't burn anything yet.



Cheers,

f