Serial access possible? YES!

LaitrKeiows · **Posted:** Tue Aug 12, 2008 3:49 pm

HOWTO add serial port to Linkstation Mini

johnbock · **Posted:** Mon Aug 18, 2008 9:43 pm

Are you sure you really need Vcc? I've never connected it using usb-serial adapters on other hardware.

johnbock · **Posted:** Sat Aug 23, 2008 10:39 am

I can't seem to get it to work either. I'm using a usb/serial adapter I use for other hardware: I know it works properly.

I too have tried to switch tx/rx, but to no avail. I've also measured vcc/gnd: they are correct on pins 3 and 4 respectively. Pin 4 being the longest of the four copper pads and pin 3 the second longest.

We could look into uboot to see what's going on, but I can't seem to find them on the buffalo's gpl web site: http://opensource.buffalo.jp/. Aren't they gpl?

Hmm, do they need pull-ups? I'll try that later...

johnbock · **Posted:** Sat Aug 23, 2008 10:56 am

I was unable to measure any continuity, to neither gnd nor vcc. Normally one would be able measure something, anything. I even swapped the probes, but also a nogo. Shouldn't I be able to measure a diode in the cpu, or something other than nothing. Endless resistance to gnd/vcc and no diode anywhere.

I guess, I'll have to take another look at the kernel gpp configuration...

davy_gravy · **Joined:** Mon Aug 28, 2006 1:15 am **Posts:** 2606

Is it the correct port/location on the board?

Also, do you have minicom configured correctly?

(I realize these are very basic questions... just thinking out loud... I've read about UBoot versions in Linksys units that don't allow the user to halt the boot process. But what you are experiencing is _not being able to see anything_...)

http://www.yamasita.jp/linkstation/ doesn't seem to have one yet...

johnbock · **Posted:** Sun Aug 24, 2008 1:52 pm

Looking at the kernel configuration for ls wsgl (mini) that the rx (mpp16) / tx (mpp 17) pins are configured for other purposes: BIT_USB_PWR, BIT_AUTO_POWER respectively.

Code:

BIT_USB_PWR        -> MVPG3[01] pin 10(?) (shutdown)
BIT_AUTO_POWER -> switch position 2

The MVPG3[01] are buck (step-down) regulators to enable software power off capabilities to the minis. AFAICS, they're for sata[01] and usb. Maybe, just maybe we can get the minis' console to work during boot. I wish I had an oscilloscope to take a look at those pins during the boot sequence...

Code:

 #elif defined(CONFIG_BUFFALO_LINKSTATION_LSWSGL_R1)
   #define CONFIG_BUFFALO_USE_LED_POWER_REVERSE
   #define BIT_LED_RESERVE1   0
   #define BIT_HDD_PWR        1  // BuffaloGpio_HddPowerO[fn]f?
   #define BIT_LED_ALARM      2
   #define BIT_LED_INFO       3
   #define BIT_LED_FUNC       9
   #define BIT_LED_ETH        11 //dummy
   #define BIT_LED_PWR        14
   #define BIT_LED_RESERVE2   14
   #define BIT_LED_RESERVE3   14
   #define BIT_LED_RESERVE4   14
   #define BIT_FUNC           15
   #define BIT_USB_PWR        16
   #define BIT_AUTO_POWER     17
   #define BIT_POWER          18
   #define BIT_HDD_PWR1       19 // BuffaloGpio_HddPowerO[fn]f?
 #endif

LaitrKeiows · **Posted:** Sun Aug 24, 2008 2:00 pm

From this guide: http://buffalo.nas-central.org/index.ph ... inkstation

Quote:

6. Connect together rxd and txd (just twisting them together is fine), and type some more. The characters which you see should appear back in the terminal window... Congratulations, you have just made a "loop back cable", and you have got the pin assignments correct.

I found that SCON-KIT/PRO I have does not pass this test, so I bought and prepared a DKU-5 cable, confirmed to be working.

johnbock wrote:

Looking at the kernel configuration for ls wsgl (mini) that the rx (mpp16) / tx (mpp 17) pins are configured for other purposes: BIT_USB_PWR, BIT_AUTO_POWER respectively.

Should I try with a new cable, or it won't work out either?

johnbock · **Posted:** Sun Aug 24, 2008 3:41 pm

LaitrKeiows wrote:

johnbock wrote:

Looking at the kernel configuration for ls wsgl (mini) that the rx (mpp16) / tx (mpp 17) pins are configured for other purposes: BIT_USB_PWR, BIT_AUTO_POWER respectively.

Should I try with a new cable, or it won't work out either?

I don't really know yet. This evening I will take a few measurements and eventually try these pins.

johnbock · **Posted:** Sun Aug 24, 2008 7:19 pm

johnbock wrote:

Code:

BIT_USB_PWR        -> MVPG3[01] pin 10(?) (shutdown)
BIT_AUTO_POWER -> switch position 2

BIT_USB_PWR goes to the ap1212 an usb power switch and pin 1 is controlled by the processor.

johnbock · **Posted:** Sun Aug 24, 2008 9:23 pm

I wasn't able to get the console working. I guess it's gonna take someone better as myself...

johnbock · **Posted:** Mon Aug 25, 2008 6:42 pm

Anybody have any ideas???? Please!!

davy_gravy · **Joined:** Mon Aug 28, 2006 1:15 am **Posts:** 2606

I emailed yasunari at yamasita.jp about this and unfortunately he doesn't have a LS Mini, so unfortunately that is a dead end (unless he picks one up or hears from someone else...)

I will keep my eyes open, though...

johnbock · **Posted:** Mon Aug 25, 2008 8:10 pm

Cool thanks bud!

Is there any way to disassemble the boot image with mkimage, perhaps a few uboot cmds embedded in an uImage would help?

LaitrKeiows · **Posted:** Sat Aug 30, 2008 4:34 pm

davy_gravy wrote:

I emailed yasunari at yamasita.jp about this and unfortunately he doesn't have a LS Mini

I could mail him mine, if he would return it after all (I live in Japan).

LaitrKeiows · **Posted:** Sat Aug 30, 2008 4:46 pm

johnbock wrote:

Anybody have any ideas???? Please!!

Can you check voltage on TXD? There must be Can you check voltage on TXD? 3.3V.

My does not have any on both contacts.

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