Adding USB to my TL-WR841N (v7.2)

This could be a pretty cheap way to get :
– Wireless & Wired network
– CPU performance
– USB 2.0
– I/Os (? still to be tested)

I found that WR841N for 23 euros…

Hack to add USB was found here : DD-WRT Forum
(Adding the serial connector is not even worth mentioning – too easy)

The USB plug was taken from and old motherboard, the 7805 from an old switch :

I then used the MR3420 opewrt image, added kmod-usb-storage / kmod-fs-vfat / kmod-nls-cp437 & iso.

Mount USB drive :

[ 219.020000] usb 1-1: new high-speed USB device number 3 using ehci-platform
[ 219.180000] scsi1 : usb-storage 1-1:1.0
[ 220.180000] scsi 1:0:0:0: Direct-Access YHS V88 5.00 PQ: 0 ANSI: 2
[ 220.190000] sd 1:0:0:0: [sda] 8108032 512-byte logical blocks: (4.15 GB/3.86 GiB)
[ 220.200000] sd 1:0:0:0: [sda] Write Protect is off
[ 220.200000] sd 1:0:0:0: [sda] Mode Sense: 0b 00 00 08
[ 220.200000] sd 1:0:0:0: [sda] No Caching mode page present
[ 220.210000] sd 1:0:0:0: [sda] Assuming drive cache: write through
[ 220.220000] sd 1:0:0:0: [sda] No Caching mode page present
[ 220.230000] sd 1:0:0:0: [sda] Assuming drive cache: write through
[ 220.230000] sda: sda1
[ 220.240000] sd 1:0:0:0: [sda] No Caching mode page present
[ 220.250000] sd 1:0:0:0: [sda] Assuming drive cache: write through
[ 220.250000] sd 1:0:0:0: [sda] Attached SCSI removable disk
[ 221.950000] FAT-fs (sda1): codepage cp437 not found
[ 224.880000] FAT-fs (sda1): codepage cp437 not found
[ 257.230000] FAT-fs (sda1): IO charset iso8859-1 not found
root@OpenWrt:/mnt/disk/mp3# df
Filesystem 1K-blocks Used Available Use% Mounted on
rootfs 1408 1168 240 83% /
/dev/root 1536 1536 0 100% /rom
tmpfs 14592 1848 12744 13% /tmp
tmpfs 512 0 512 0% /dev
/dev/mtdblock3 1408 1168 240 83% /overlay
overlayfs:/overlay 1408 1168 240 83% /
/dev/sda1 4043380 895652 3147728 22% /mnt/disk

And of course, tested madplay performances…


root@OpenWrt:/mnt/disk/mp3# ls
PeterGabriel-Live-DontGiveUp.mp3
root@OpenWrt:/mnt/disk/mp3# time madplay -o null:null PeterGabriel-Live-DontGiveUp.mp3
MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
11541 frames decoded (0:05:01.4), -0.3 dB peak amplitude, 0 clipped samples
real 0m 20.37s
user 0m 20.32s
sys 0m 0.05s
root@OpenWrt:/mnt/disk/mp3# time madplay -v -o raw:output.raw PeterGabriel-Live-DontGiveUp.mp3
MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
00:05:01 Layer III, 128 kbps, 44100 Hz, stereo, no CRC
11541 frames decoded (0:05:01.4), -0.3 dB peak amplitude, 0 clipped samples
real 0m 53.79s
user 0m 31.25s
sys 0m 2.29s
root@OpenWrt:/mnt/disk/mp3# ls -lrt
-rwxr-xr-x 1 root root 4811971 Jul 16 20:39 PeterGabriel-Live-DontGiveUp.mp3
-rwxr-xr-x 1 root root 53180928 Jul 18 11:19 output.raw
root@OpenWrt:/mnt/disk/mp3#