Howto add serial port to WL500gx

[Josephus]

The Asus wl500g deluxe has uart pinout onboard, so 2 serial ports can be added to the unit.
The only difference between wl500g and wl500gx that the deluxe does not require a UART chip, so a simple RS232 transceiver will do the trick.

Here are my experiences adding a single serial port to the router
The parts you need:
- 1 MAX3232 IC (SO-IC)
- 5 1uF capacitors
- cables, connectors

I attached the PCB layout I made, and a few pictures that might help.
There are 2 jumpers on the pcb, which switches between the Tx-Rx, so it doesn't matter what kind of serial cable you actually use.
Good juper configurations:
._ ._ and _. _.
Don't mix them! Next time i'm going to use a switch instead

You need to connect the router's 3.3v, GND, UART_TX0, UART_RX0 pins to the left side of the pcb, set the jumpers, and connect a DB9 connector to the right side.

Note: Actually i was able to add the serial port without actually removing the warranty sticker. I left the screw with the sticker untouched, and stretched the unit just enough to get the connector on the pins.

Important: Don't try this, unless you know what you are doing. I take no responsibility for damaging your router

CFE version 1.0.37 for BCM947XX (32bit,SP,LE)
Build Date: ¤*  7¤ë 16 19:48:38 CST 2004 (root@PaNLinux)
Copyright (C) 2000,2001,2002,2003 Broadcom Corporation.

Initializing Arena.
Initializing Devices.
et0: Broadcom BCM47xx 10/100 Mbps Ethernet Controller 1.3.2.0
rndis0: Broadcom USB RNDIS Network Adapter (P-t-P)
CPU type 0x29007: 200MHz
Total memory: 0x1000000 bytes (16MB)

Total memory used by CFE:  0x80300000 - 0x80436CF0 (1273072)
Initialized Data:          0x803311B0 - 0x80333540 (9104)
BSS Area:                  0x80333540 - 0x80334CF0 (6064)
Local Heap:                0x80334CF0 - 0x80434CF0 (1048576)
Stack Area:                0x80434CF0 - 0x80436CF0 (8192)
Text (code) segment:       0x80300000 - 0x803311B0 (201136)
Boot area (physical):      0x00437000 - 0x00477000
Relocation Factor:         I:00000000 - D:00000000

Device eth0:  hwaddr 00-11-D8-XX-XX-XX, ipaddr 192.168.1.1, mask 255.255.255.0
        gateway not set, nameserver not set
Rescue Flag disable.
Reading :: TFTP Server.
Failed.: Timeout occured
Loader:raw Filesys:raw Dev:flash0.os File: Options:(null)
Loading: ...... 1748992 bytes read
Entry at 0x80001000
Closing network.
Starting program at 0x80001000
CPU revision is: 00029007

Primary instruction cache 8kB, physically tagged, 2-way, linesize 16 bytes.

Primary data cache 4kB, 2-way, linesize 16 bytes.

Linux version 2.4.29 (josephus@arrakis) (gcc version 3.3.5) #1 Sun Mar 6 02:01:59 CET 2005

[rwhitby]

I have successfully connected to the serial port on J5.

I've used a small converter board from a usb->serial cable (an old phone data cable), and will mount that board inside the case, with just a USB device port added to the back panel. Pictures later ...

Here is the output from the serial console on boot (running Oleg's firmware).

CFE version 1.0.37 for BCM947XX (32bit,SP,LE)
Build Date: ¤G  3¤ë  1 16:49:41 CST 2005 (root@PaNLinux)
Copyright (C) 2000,2001,2002,2003 Broadcom Corporation.

Initializing Arena.
Initializing Devices.
et0: Broadcom BCM47xx 10/100 Mbps Ethernet Controller 1.3.2.0
rndis0: Broadcom USB RNDIS Network Adapter (P-t-P)
CPU type 0x29007: 200MHz
Total memory: 0x2000000 bytes (32MB)

Total memory used by CFE:  0x80300000 - 0x80436F10 (1273616)
Initialized Data:          0x803313D0 - 0x80333760 (9104)
BSS Area:                  0x80333760 - 0x80334F10 (6064)
Local Heap:                0x80334F10 - 0x80434F10 (1048576)
Stack Area:                0x80434F10 - 0x80436F10 (8192)
Text (code) segment:       0x80300000 - 0x803313D0 (201680)
Boot area (physical):      0x00437000 - 0x00477000
Relocation Factor:         I:00000000 - D:00000000

Device eth0:  hwaddr 00-11-D8-??-??-??, ipaddr 192.168.??.??, mask 255.255.255.0
        gateway not set, nameserver not set
Rescue Flag disable.
Reading :: TFTP Server.
Failed.: Timeout occured
Loader:raw Filesys:raw Dev:flash0.os File: Options:(null)
Loading: .. 3560 bytes read
Entry at 0x80001000
Closing network.
Starting program at 0x80001000
cpu probe
prom init
cpu report
CPU revision is: 00029007
Primary instruction cache 8kb, linesize 16 bytes (2 ways)
Primary data cache 4kb, linesize 16 bytes (2 ways)
Linux version 2.4.20 (root@omnibook) (gcc version 3.2.3 with Broadcom modifications) #62 Mon Mar 14 21:39:22 MSK 2005
Setting the PFC value as 0x15
Determined physical RAM map:
 memory: 02000000 @ 00000000 (usable)
On node 0 totalpages: 8192
zone(0): 8192 pages.
zone(1): 0 pages.
zone(2): 0 pages.
Kernel command line: root=/dev/mtdblock2 noinitrd init=/linuxrc console=ttyS0,115200
CPU: BCM5365 rev 1 at 200 MHz
Calibrating delay loop... 199.47 BogoMIPS
Memory: 30128k/32768k available (1755k kernel code, 2640k reserved, 220k data, 68k init, 0k highmem)
Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
Checking for 'wait' instruction...  unavailable.
POSIX conformance testing by UNIFIX
PCI: Fixing up bus 0
PCI: Fixing up bridge
PCI: Fixing up bus 1
Linux NET4.0 for Linux 2.4
Based upon Swansea University Computer Society NET3.039
Initializing RT netlink socket
Starting kswapd
Journalled Block Device driver loaded
devfs: v1.12c (20020818) Richard Gooch (rgooch@atnf.csiro.au)
devfs: boot_options: 0x1
NTFS driver v1.1.22 [Flags: R/O]
pty: 256 Unix98 ptys configured
Serial driver version 5.05c (2001-07-08) with MANY_PORTS SHARE_IRQ SERIAL_PCI enabled
ttyS00 at 0xb8000300 (irq = 3) is a 16550A
ttyS01 at 0xb8000400 (irq = 0) is a 16550A
loop: loaded (max 8 devices)
PPP generic driver version 2.4.2
PPP Deflate Compression module registered
PPP BSD Compression module registered
MPPE/MPPC encryption/compression module registered
 Amd/Fujitsu Extended Query Table v1.1 at 0x0040
number of CFI chips: 1
Flash device: 0x400000 at 0x1c000000
Physically mapped flash: squashfs filesystem found at block 936
Creating 5 MTD partitions on "Physically mapped flash":
0x00000000-0x00040000 : "pmon"
0x00040000-0x003e0000 : "linux"
0x000ea190-0x003e0000 : "rootfs"
0x003f0000-0x00400000 : "nvram"
0x003e0000-0x003f0000 : "config"
sflash: found no supported devices
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP
IP: routing cache hash table of 512 buckets, 4Kbytes
TCP: Hash tables configured (established 2048 bind 4096)
ip_conntrack version 2.1 (256 buckets, 2048 max) - 344 bytes per conntrack
ip_conntrack_pptp version 1.9 loaded
ip_nat_pptp version 1.5 loaded
ip_tables: (C) 2000-2002 Netfilter core team
ipt_time loading
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
IPv6 v0.8 for NET4.0
IPv6 over IPv4 tunneling driver
NET4: Ethernet Bridge 008 for NET4.0
802.1Q VLAN Support v1.7 Ben Greear <greearb@candelatech.com>
All bugs added by David S. Miller <davem@redhat.com>
FAT: bogus logical sector size 38400
FAT: bogus logical sector size 38400
NTFS: Unable to set blocksize 512.
VFS: Mounted root (squashfs filesystem) readonly.
Mounted devfs on /dev
Freeing unused kernel memory: 68k freed
Algorithmics/MIPS FPU Emulator v1.5
eth0: Broadcom BCM47xx 10/100 Mbps Ethernet Controller 1.3.2.0
robosw_attach_ocp: no Robo device on OCP bus
PCI: Enabling device 01:03.0 (0004 -> 0006)
eth1: Broadcom BCM4320 802.11 Wireless Controller 3.90.7.0
device eth1 entered promiscuous mode
eth0.1: No such device
device eth0 entered promiscuous mode
br0: port 2(eth0) entering learning state
br0: port 1(eth1) entering learning state
br0: port 2(eth0) entering forwarding state
br0: topology change detected, propagating
br0: port 1(eth1) entering forwarding state
br0: topology change detected, propagating
usb.c: registered new driver usbdevfs
usb.c: registered new driver hub
usb-uhci.c: $Revision: 1.275 $ time 20:26:03 Mar  3 2005
usb-uhci.c: High bandwidth mode enabled
PCI: Enabling device 01:02.0 (0000 -> 0001)
usb-uhci.c: USB UHCI at I/O 0x100, IRQ 2
usb-uhci.c: Detected 2 ports
usb.c: new USB bus registered, assigned bus number 1
hub.c: USB hub found
hub.c: 2 ports detected
PCI: Enabling device 01:02.1 (0000 -> 0001)
usb-uhci.c: USB UHCI at I/O 0x120, IRQ 2
usb-uhci.c: Detected 2 ports
usb.c: new USB bus registered, assigned bus number 2
hub.c: USB hub found
hub.c: 2 ports detected
usb-uhci.c: v1.275:USB Universal Host Controller Interface driver
PCI: Enabling device 01:02.2 (0000 -> 0002)
ehci_hcd 01:02.2: PCI device 1106:3104
ehci_hcd 01:02.2: irq 2, pci mem c00af000
usb.c: new USB bus registered, assigned bus number 3
PCI: 01:02.2 PCI cache line size set incorrectly (0 bytes) by BIOS/FW, correcting to 32
ehci_hcd 01:02.2: USB 2.0 enabled, EHCI 1.00, driver 2003-Dec-29/2.4
hub.c: USB hub found
hub.c: 4 ports detected
usb.c: registered new driver usblp
printer.c: v0.13: USB Printer Device Class driver
usb.c: registered new driver audio
audio.c: v1.0.0:USB Audio Class driver
Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
PCI devices found:
    Class 0501: PCI device 14e4:0800 (rev 1).
    Class 0200: PCI device 14e4:4713 (rev 1).
    Class 1000: PCI device 14e4:4718 (rev 1).
    Class 0c03: PCI device 14e4:4715 (rev 1).
    Class 0604: PCI device 14e4:0804 (rev 1).
    Class 0b30: PCI device 14e4:0816 (rev 1).
    Class 0500: PCI device 14e4:080f (rev 1).
    Class 0600: PCI device 14e4:5365 (rev 0).
    Class 0c03: PCI device 1106:3038 (rev 97).
    Class 0c03: PCI device 1106:3038 (rev 97).
    Class 0c03: PCI device 1106:3104 (rev 99).
    Class 0280: PCI device 14e4:4320 (rev 3).
echo for PaN ::: &&&PaN

[palbeda]

Hi,

I was wondering if you manage to send output to your serial port.
There is another thread about adding USB serial ports and all people I heard (including myself) trying to actually use the port found out that the wl500 reboots after sending a few characters to that port. Maybe you run into problems just like us actually using the port. Unfortunately I do not know of any fixes for this problem.

Regards

Peter

[rwhitby]

Originally Posted by rwhitby

I've used a small converter board from a usb->serial cable (an old phone data cable), and will mount that board inside the case, with just a USB device port added to the back panel. Pictures later ...

Operation is confirmed, and here are the promised pictures. I left room between the ethernet ports and the new usb device port just in case I decide to add the extra two USB host ports later ...

-- Rod

[sodb]

It took me a few seconds to understand the config. Related to palbeda's remark, this set-up is the other way around. Where palbeda connected a serial<->USB to the USB port of the Asus, in this set-up you connect the serial of the asus to the USB of e.g. a PC. Therefore, no max232 voltage convertor is needed. On the other hand, for home automation applications, a native serial port on the ASUS is to be prefered.

[rwhitby]

Originally Posted by sodb

It took me a few seconds to understand the config. Related to palbeda's remark, this set-up is the other way around. Where palbeda connected a serial<->USB to the USB port of the Asus, in this set-up you connect the serial of the asus to the USB of e.g. a PC. Therefore, no max232 voltage convertor is needed. On the other hand, for home automation applications, a native serial port on the ASUS is to be prefered.

If you want a non-console serial port on the wl500g (e.g. for home automation), then the easiest way is to just plug in a pl2303-based usb to serial converter cable). I have sent Oleg a patch to enable such usage in his firmware, and I hope it will be included in the next version he releases.

-- Rod

[Oleg]

Originally Posted by rwhitby

If you want a non-console serial port on the wl500g (e.g. for home automation), then the easiest way is to just plug in a pl2303-based usb to serial converter cable). I have sent Oleg a patch to enable such usage in his firmware, and I hope it will be included in the next version he releases.

-- Rod

yes, pl2303 support would be in the next firmware. So it would be possible to connect some cellular phones, which use pl2303 in their data cables.

[sodb]

I have a 500gx running 1.9.2.7-5a. Before opening the case and possible break warranty I wanted to check how the internal serials are controlled.
I see the following:

[admin@wl500gx root]$ more /proc/tty/driver/serial
serinfo:1.0 driver:5.05c revision:2001-07-08
0: uart:16550A port:B8000300 irq:3 baud:115740 tx:630 rx:0 RTS|DTR
1: uart:16550A port:B8000400 irq:0 tx:0 rx:0 CTS|DSR|CD

That shows that two ports are available. Usually (in other Linux systsems) the serials devices have names /dev/ttyS0 and /dev/ttyS1. In de asus I only see /dev/tts/0 and /dev/tts/1.
trying to set baud rate using busybox stty applet results in the following:

[admin@wl500gx harddisk]$ ./busybox stty 9600 < /dev/tts/0
[admin@wl500gx harddisk]$ more /proc/tty/driver/serial
serinfo:1.0 driver:5.05c revision:2001-07-08
0: uart:16550A port:B8000300 irq:3 baud:9615 tx:630 rx:0 RTS|DTR
1: uart:16550A port:B8000400 irq:0 tx:0 rx:0 CTS|DSR|CD

It seems that the baud rate is only approximately set on the device. Probably accurate enough. Echoing some characters shows:

before
0: uart:16550A port:B8000300 irq:3 baud:9615 tx:630 rx:0 RTS|DTR
after echo "1234567890" > /dev/tts/0 it reads:
0: uart:16550A port:B8000300 irq:3 baud:9615 tx:642 rx:0 RTS|DTR

showing that the charaters are being transmitted.

Stty changes can also be made to second port; however, echoing to the second port /dev/tts/1 results in a full hang-up of the system. Need to power cycle.

Does anyone has experimence with sending/receiving messages through both the serials from the shell (thus not as default serial terminal at boot-up as is shown earlier in this thread)?

Another question is about the logical levels of this interface. Is it based on 3.3V or normal TTL 5V signals? In other words, can I connect a normal MAX232 for the signal conversion between RS-232 and the uart ports of the WL500G?

[sodb]

I installed the MAX3232 on serial 0 (/dev/tts/0) and it worked immediately. I used a flat cable with a dual row connector and I was able, as suggested by Josephus, to hook the connector to the internal PCB connector without removing the middle 'guarantee' screw. I even could easely close the box again and lead the flat cable out of the side of the box.
While booting I see the same messages in serial console as shown earlier in this thread. For some experiments I want to disable the console mapped to serial0. I read that console is enable in firmware (1.9.2.7-cr5). Does anyone know how to disable the console or how to kill the proces driving the consoleso that the serial port can be freed for own applications?
I see output appearing in the terminal session when I do an echo "Hello" > /dev/tts/0 . I can even reset the terminal baud rate using busybox stty 9600 < /dev/tts/0 and output characters on this baudrate. However, as soon as I type a character in the serial terminal, the terminal is reset back to the original speed of 115200 baud as shown below

[admin@wl500gx harddisk]$ ./busybox stty 9600 < /dev/tts/0
[admin@wl500gx harddisk]$ ./busybox stty -a < /dev/tts/0
speed 9600 baud; rows 0; columns 0;
intr = <undef>; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-parenb -parodd cs8 hupcl -cstopb cread clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff
-iuclc -ixany -imaxbel
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
-isig -icanon iexten -echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
echoctl echoke

<type a Carriage Return in terminal session>

[admin@wl500gx harddisk]$ ./busybox stty -a < /dev/tts/0
speed 115200 baud; rows 0; columns 0;
intr = <undef>; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-parenb -parodd cs8 hupcl -cstopb cread clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff
-iuclc -ixany -imaxbel
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
-isig -icanon iexten -echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
echoctl echoke

It seems that a process whatches the serial port and resets its baudrate when receiving input. Any suggestions? I tried the second serial port (UART_RX1/TX1) , but as described earlier, the systems hangs as soon as output is sent to this port. Has that anything to to with IRQ 0 used by this port?

[sodb]

I recompiled kernel with the following change in kernel.config

CONFIG_CMDLINE="root=/dev/mtdblock2 noinitrd init=/linuxrc console=null"

Now the console is disabled and is free to use for own purposes. Directly writing and reading to and from device /dev/tts/0 works fine.
Still, accessing second port /dev/tts/1 causes hang-up of asus.

[Oleg]

have you disabled flow control on the tts/1?

[sodb]

Hey, thanks Oleg,

i just typed

 /tmp/harddisk/busybox stty -crtscts   < /dev/tts/1

and now I can input and output to /dev/tts/1. However, after disabling the console I actually did not try the second port anymore. Currently I can not reboot, but later I will check the status.
This is what I see when doing

[admin@wl500gx root]$ more /proc/tty/driver/serial
serinfo:1.0 driver:5.05c revision:2001-07-08
0: uart:16550A port:B8000300 irq:3 baud:9615 tx:7 rx:0
1: uart:16550A port:B8000400 irq:3 baud:115740 tx:49 rx:24 CTS|DSR|CD

I wonder what caused the change from IRQ:0 to IRQ:3 for dev/tts/1? After reboot I will check defaults and compare. From the tx and rx counters one can see if the interface really works.
Currently, I am happy with two simulaneous serial ports on the wl500gx.

[Duke]

Can you check please both ports working well at the same time? If such, maybe the patching of the kernel with disabling IRQ masking at tts/1 when ttys/0 is a console port isn't a bad idea.
I'll try o check 18xx GPL sources located on utilities CD, if Oleg didn't do so yet

[sodb]

On two sessions I started cat /dev/tts/0 and cat /dev/tts/1 respectively. Because I only have a single serial port on my laptop I can only test alternatevely. That works.
Then I did a test where I connected Rx0 to Tx1 and Rx1 to Tx0. Then 4 sessions, 2 as described before, other two with echo commands to the respective ports. On echo from /tts/1 to /tts/0 works. When I issue an echo the other way around, the cat sessions keep scrolling and the echo sessions take a long time to finish. I can CRTL-C all the sessions. I think there is a conflict with the same IRQ3 for both lines. Is there another free IRQ available and could that be used for serial /tts/1?

[Oleg]

Originally Posted by sodb

Is there another free IRQ available and could that be used for serial /tts/1?

No, both uarts use the same irq.