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3.3V TTL to USB converter for DIR685 storage router

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samurai_ttl

Beginner

Posts: 16

1

Sunday, July 31st 2011, 11:27pm

3.3V TTL to USB converter for DIR685 storage router

Hi,

Can someone please suggest a good 3.3V TTL to USB converter?

I googled and only see USB-TTL converter. I want to connect the console port ( 3.3V TTL ) to my laptop USB port.

TIA

uzer2

Beginner

Posts: 6

2

Tuesday, August 2nd 2011, 9:08pm

HWguru

NAS2000-Team

Posts: 1,039

Location: Wien

3

Thursday, August 4th 2011, 9:43am

Hi,
the best would be one with a FTDI FT232R or RL chip. You should be able to find one at ebay in the range from 7 to 20€.
This offers you the opportunity to use it for the JTAG unbricking in case of a destroyed bootloader.

Have a look at the wiki guide or HowTos

HWguru
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samurai_ttl

Beginner

Posts: 16

4

Friday, August 5th 2011, 4:47am

Thanks guys...

I got FTDI 6pin TTL-232R-3V3 USB adapter which has FT232RQ chip. Since USB port on the laptop would provide VCC +5VDC, I guess I don't need to connect VCC +3.3VDC connection available on the router DIR-685 board, just TX, RX and GND would suffice. Am I right?

This post has been edited 1 times, last edit by "samurai_ttl" (Aug 5th 2011, 6:01am)

HWguru

NAS2000-Team

Posts: 1,039

Location: Wien

5

Friday, August 5th 2011, 12:01pm

Hi,
you are right.
The chip has a built in 3.3V voltage regulator and does not need to be powered from the target hardware.

HWguru
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samurai_ttl

Beginner

Posts: 16

6

Friday, August 5th 2011, 5:59pm

Thank you for your time and replies, appreciate it. :thumbsup:

samurai_ttl

Beginner

Posts: 16

7

Saturday, August 6th 2011, 7:01am

So I tried the adapter cable but I don't see any console output. Tried at different speeds in putty and reversing tx and rx didn't help either.
I know the cable is working ( tested by shorting tx and rx ). I tried the connection per the pinout in the wiki. The cpu is SL3516 and Spansion flash.

AQUAR

Trainee

Posts: 116

Location: Australia

8

Saturday, August 6th 2011, 9:24am

Hi,

Maybe you are connecting the adapter to the NAS before NAS power up?
Have everything setup: ie console running and able to communicate with adapter(loop back test).
Remove loop back bridge and get ready to quickly plug the adapter on to the NAS shortly after powering it up.

Aquar

HWguru

NAS2000-Team

Posts: 1,039

Location: Wien

9

Saturday, August 6th 2011, 10:43am

I think we need some more information ...

- which NAS?
- does it boot and is accessible?
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AQUAR

Trainee

Posts: 116

Location: Australia

10

Saturday, August 6th 2011, 12:18pm

I think he is talking about a fancy router/ NAS combination from Dlink.
But we definitely need more info about the problem/purpose for
this serial console access requirement.

samurai_ttl

Beginner

Posts: 16

11

Saturday, August 6th 2011, 7:58pm

I tried by connecting the device after and before power up but no avail.

This is DIR685 storage router. It does boot and I can telnet to it. It's SL3516 based and has Spansion flash.
The console serial connection is 4 pin header and followed the signal connections per wiki ( hopefully there are same for this device )..

This devices has an issue of noisy fan. I thought to look into this and see if I can find out the reason and see if there is a way to fix it.
It has 2x10 maybe JTAG connector but without header.

Thanks

AQUAR

Trainee

Posts: 116

Location: Australia

12

Sunday, August 7th 2011, 5:00am

Hi,

It would be most improbable if the firmware has some built in fan controller software.
Fan noise is a mechanical issue so if it spins to fast then just slow it down with some series resistance.
If the bearings are noisy then oil them.
Best of all you could just buy a better quality fan.

Fiddling with JTAG or serial port are for unbricking and could just as easily do the reverse for you.
If you want to delve into the firmware a bit more then use SSH and look for log files.

:beer: but I think HWguru will probably want to do this :closed:

Aquar

samurai_ttl

Beginner

Posts: 16

13

Sunday, August 7th 2011, 8:30am

Well the noisy fan issue is basically spinning at full speed when you put the drive inside the router. This router has an internal drive bay and also 2x USB port for connecting external drives. The fan is meant for cooling off the drive. The fan spinning at high or full speed most of the time if not all the time means to me is a poor thermal design of the device which apparently the case here. The firmware has smart monitor and provides the drive temperature to the fan controller driver. I don't see a separate drive for fan control but maybe it's inbuilt in the kernel either acpi or something. It seems there is a defined threshold of 46-47F and as soon this is crossed, the driver spins the fan at full speed causing irritating noise. I couldn't find what that driver is and any command to see the fan status etc. Other option I can think of is to put an extra fan/blower in series or parallel but I got to know power supply setting/capability of the fan controller. Need to see what electronics and driver plays here. Also there are other issues with this router which says a buggy firmware.


BTW, I tried the other connection pinout of the serial console but still don't see console output.

This post has been edited 2 times, last edit by "samurai_ttl" (Aug 8th 2011, 3:14am)

samurai_ttl

Beginner

Posts: 16

14

Monday, August 8th 2011, 2:25am

Ok.. I go the connection working. Happy camper now.... :)

AQUAR

Trainee

Posts: 116

Location: Australia

15

Monday, August 8th 2011, 11:49am

Hi,

Curious for others that have this device:
What was the issue with the connection?
What is the serial port pinout of this device?

Success in finding a way to alter the temperature trigger point for full fan speed.
Please share it if you do ;) .

Aquar

samurai_ttl

Beginner

Posts: 16

16

Monday, August 8th 2011, 6:14pm

Here is the serial port pinout:

Source code

 
1
2
3
4
5
6
7
8

PINS:

o o o _ o
| | |   |
| | |   RX
| | VCC
| GND
TX


Serial connection config: 19200 baud, 8 bits, 1 stop bit, no parity, no flow control. I used putty.

For the FTDI adapter, I had to reverse the TX, RX at the connector end.

I'll share the information about fan speed as soon as I find a way out.

AQUAR

Trainee

Posts: 116

Location: Australia

17

Tuesday, August 9th 2011, 12:53pm

Hi,

As you noticed, both PC and NAS are considered DTE and require a null modem connection to talk to each other.

I am sure there will be an interest in your findings re quietting the fan through firmware patching.
You should start a new topic when you wish to share your effort ;) .

Aquar

HWguru

NAS2000-Team

Posts: 1,039

Location: Wien

18

Wednesday, August 10th 2011, 9:54am

Hi,
it is always the same - an Rx (receive) pin needs to be connected to a Tx (transmit) pin.

As Aquar said I will close now as this problem is solved.
We would be very glad if you start a new thread and share other tweaks with us :lean:

HWguru

Note: I extended the title and added a code section for the pinout for better readability.
Leute ohne Laster haben oft wenige Tugenden...
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