Difference between revisions of "Add a Serial port to the LS MINI"
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Apparently there are two traces that have been interrupted which would allow serial port access. | Apparently there are two traces that have been interrupted which would allow serial port access. | ||
− | These traces have been interrupted UNDER a SMD capacitor at position C54. | + | These traces have been interrupted UNDER a SMD capacitor at position C54. Junker<ref>[http://www.yamasita.jp/cgi-bin/BBS/eztree.cgi?action=view&view_num=5166 Original Junker's message No.5166 at Hack BBS]</ref> (see Yamasita's article/reference) discovered |
+ | the way first<ref>[http://www.yamasita.jp/linkstation/2008/08/080831__patches_for_serial_console.html シリアルコンソールのためのパッチ / patches for serial console:LS-WSGL/R1 ]</ref>. Apparantly the pinheaders from the [[SCON-KIT/ PRO quick manual|SCON-KIT/ PRO]] can be fit into the case quite easily as well<ref>[http://www.yamasita.jp/linkstation/2008/09/080906__soldering_a_serial_connecter.html シリアルコネクタの半田付け / soldering a serial connecter:LS-WSGL/R1 ]</ref>. | ||
− | [[User:Laitr Keiows |Laitr Keiows]] and | + | [[User:Laitr Keiows |Laitr Keiows]] and [[User:Johnbock|Johnbock]] duplicated his efforts<ref>[http://buffalo.nas-central.org/forums/viewtopic.php?f=61&t=10471 The Buffalo NAS hacking Forums:Serial access possible? YES!]</ref> |
=Method= | =Method= | ||
+ | First take it apart: | ||
+ | * <big>[[Disassemble the LS MINI]]</big> | ||
+ | |||
+ | Then you will need to find some way to resurrect the traces that are interrupted under C54. | ||
+ | |||
==C54== | ==C54== | ||
We need to fix these wires which go under C54: | We need to fix these wires which go under C54: | ||
{| | {| | ||
|- | |- | ||
− | ||[[Image:LSMINI-Serialport-c54.jpg|200px|The traces are visible under c54]] | + | ||[[Image:LSMINI-Serialport-c54.jpg|200px|thumb|Frontside - The traces are visible under c54]] |
− | ||[[Image:LSMINI-Serialport-before.jpg|200px]] | + | ||[[Image:LSMINI-Serialport-before.jpg|200px|thumb|Backside]] |
|} | |} | ||
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This method requires absolutely no soldering. | This method requires absolutely no soldering. | ||
− | Lay a layer of a scotch tape between holes, just not to cover them. | + | # Lay a layer of a scotch tape between holes, just not to cover them. |
+ | # Use a strand of high flexible low oxygen copper wire. | ||
+ | # Thread it through both holes. | ||
+ | # Fix it with a scotch tape on the back side. | ||
+ | # Cut remainders on the front side, leaving about 2 mm. | ||
+ | # Repeat from step 2 with the second thread. | ||
+ | # Be sure not to shorten anything else. | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
{| | {| | ||
|- | |- | ||
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===Method 2: Bridge the traces (on the frontside)=== | ===Method 2: Bridge the traces (on the frontside)=== | ||
+ | This method requires a steady hand and good soldering skills. | ||
+ | |||
+ | Use two strands of high flexible low oxygen copper wire. | ||
+ | # Locate and carefully remove C54 from its pads. | ||
+ | # Clean the area with rubbing alcohol and a tiny brush. | ||
+ | # Cut two stands of high flexible copper wire to length. | ||
+ | # Solder each of the strands to the vertically aligned pads. | ||
+ | # Resolder C54 to its' original position. | ||
+ | # Ensure no shorting has take place while soldering. | ||
+ | |||
{| | {| | ||
|- | |- | ||
− | ||[[Image:LSMINI-Serialport-c54.jpg|200px]] | + | ||[[Image:LSMINI-Serialport-c54.jpg|200px|thumb|Locate C54 on the upper (processor) side of the PCB.]] |
− | ||[[Image:LSMINI-Serialport-c54bridged. | + | ||[[Image:LSMINI-Serialport-c54unbridged.png|200px|thumb|Carefully remove C54 (we need it later) from it's pads.]] |
+ | ||[[Image:LSMINI-Serialport-c54bridged.png|200px|thumb|Using two strands of high flexible copper wire, solder each of the two vertically aligned traces.]] | ||
|} | |} | ||
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|- | |- | ||
|| | || | ||
− | [[Image: | + | [[Image:LSMINI-Serialport-after.jpg|thumb|Wire colors referenced in table]] |
+ | || | ||
{| style="background:Gainsboro;border-collapse:collapse;border:solid 1px black" | {| style="background:Gainsboro;border-collapse:collapse;border:solid 1px black" | ||
|+ | |+ | ||
Line 55: | Line 72: | ||
| style="border:solid 1px white" |'''Pin ''' | | style="border:solid 1px white" |'''Pin ''' | ||
| style="border:solid 1px white" |'''Signal''' | | style="border:solid 1px white" |'''Signal''' | ||
+ | | style="border:solid 1px white" |'''Wire Color''' | ||
|- | |- | ||
| style="border:solid 1px white"|1 | | style="border:solid 1px white"|1 | ||
− | | style="border:solid 1px white"|Transmit ( | + | | style="border:solid 1px white"|Transmit (TxD) |
+ | | style="border:solid 1px white"|Green | ||
|- | |- | ||
| style="border:solid 1px white"|2 | | style="border:solid 1px white"|2 | ||
− | | style="border:solid 1px white"|Receive ( | + | | style="border:solid 1px white"|Receive (RxD) |
+ | | style="border:solid 1px white"|White | ||
|- | |- | ||
| style="border:solid 1px white"|3 | | style="border:solid 1px white"|3 | ||
− | | style="border:solid 1px white"|Power | + | | style="border:solid 1px white"|Power 3.3V (Vcc) |
+ | | style="border:solid 1px white"|NC | ||
|- | |- | ||
| style="border:solid 1px white"|4 | | style="border:solid 1px white"|4 | ||
| style="border:solid 1px white"|Ground (GND) | | style="border:solid 1px white"|Ground (GND) | ||
+ | | style="border:solid 1px white"|Red | ||
|} | |} | ||
|} | |} |
Latest revision as of 06:24, 10 September 2008
Contents
Background
Apparently there are two traces that have been interrupted which would allow serial port access.
These traces have been interrupted UNDER a SMD capacitor at position C54. Junker[1] (see Yamasita's article/reference) discovered the way first[2]. Apparantly the pinheaders from the SCON-KIT/ PRO can be fit into the case quite easily as well[3].
Laitr Keiows and Johnbock duplicated his efforts[4]
Method
First take it apart:
Then you will need to find some way to resurrect the traces that are interrupted under C54.
C54
We need to fix these wires which go under C54:
Method 1: reconstruct the traces (on the backside)
This method requires absolutely no soldering.
- Lay a layer of a scotch tape between holes, just not to cover them.
- Use a strand of high flexible low oxygen copper wire.
- Thread it through both holes.
- Fix it with a scotch tape on the back side.
- Cut remainders on the front side, leaving about 2 mm.
- Repeat from step 2 with the second thread.
- Be sure not to shorten anything else.
Method 2: Bridge the traces (on the frontside)
This method requires a steady hand and good soldering skills.
Use two strands of high flexible low oxygen copper wire.
- Locate and carefully remove C54 from its pads.
- Clean the area with rubbing alcohol and a tiny brush.
- Cut two stands of high flexible copper wire to length.
- Solder each of the strands to the vertically aligned pads.
- Resolder C54 to its' original position.
- Ensure no shorting has take place while soldering.
Pinout of Port
|
Use a Level Shifter
The serial port signals from the processor are only 3.3V. For proper RS-232 12V signaling, an RS-232 level shifter needs to be added. These are very common in PDA serial cables also, but can be purchased
Build your own LVTTL/RS232 or LVTTL/USB interface
- LVTTL/RS232 - Building a Custom Serial Interface
- LVTTL/USB - Use a Nokia Serial Cable on an ARM9 Linkstation
- LVTTL/USB - Use a cheap phone sync cable with the serial port
Buy your own TTL Level Shifter
- LVTTL/RS232 - MAX232 based from Futurelec - MINIRS2323V
- LVTTL/USB - FTDI chip based cable - TTL-232R-3V3
Usage considerations for the TTL-232R-3V3
|
A working/tested pinout/wire-color scheme is:
|
- Solder the 4-pin header to the board. Make sure you don't have shorts.
- You will need to switch wires on the TTL-232R-3V3 cable. Use a sharp object to lift the plastic tabs and carefully pull the wires out. Rearrange them according to the table above (black, empty, orange, yellow, empty, empty) and slide those wires back in. Tape the other wires to make sure they don't short anything.
- When plugging in the cable, make sure black aligns with GND, yellow with TXD, and orange with RXD.
- Connect the USB cable to your computer, start a terminal program with the right settings.
- Turn on the device, you should see output from the bootloader in couple seconds.
Serial Port Output
LS Mini: Serial Port Output - Boot-Log