Remote controller reverse engineered

Do you remember the DVD player I’m using? It’s salvaged from junk basically, and was repaired by replacing the whole power supply with a ATX p/s. The most annoyed problem of this machine is it’s lack of remote controller. That’s vital because you can’t do fast forwarding, rewarding, changing subtitle, etc. without remote.

I tried that sort of N in 1 remote controller, but without success. Apparently this ‘Universal’ brand dvd use some kind of property protocol.

Luckily, one of my friends has a dvd which is based on similar design (sunplus). The remote controller came with that dvd can be used to control my dvd somehow. Several buttons works but with different functions.

Then I used OmniRemote to record that working button signal, and looked in the database produced by OR. It is found that my dvd actually use NEC protocol with Address code 0×00FF.

Working out exact key code is a pain because you basically need to transmit all possible key codes manually to check out the corresponding function. I use my Sony Clie handheld with Clie RMC to check the code. RMCEnhancer is very useful to produce customized IR code library.

Two nights, problem resolved.

Bargin!!

Yesterday & today:

$4 for a set of PlayStation (working)

$2 for a HP ScanJet 3300C (working)

$5 for two 10/100M network switch (untested)

A free USB camera (untested)

now I’m looking for bargin DV camcorder and LCD display, even faulty.

What a pity!

I missed the long expecting Recreational Vehicle expo yesterday. I was thinking Apr. 14 would be next saturday.

There’s another pity today. Tried my best to purchase a matress pad from IKEA (one hour driving from my home) , I found I purchased a wrong size. Although I always thought my bed is queen size, actually it’s a double-size one!!! My fault is, after living in this apartment for one year, I didn’t actually measure the size of my bed to make sure what size it is. It’s a big lession, somebody must take the responsibility. I have to replace it sometime next week. A two hours’ waste of time and fuel:(

MIDI workstation Day 2

Finally, all connections are beautifully setup. Now the D-9 MIDI port looks like original design:) Inside the box, I have to directly solder the three signals on the sound card board.

To get the best possible MIDI quality with the available hardwares, the original ESS1868 ISA card is replaced by a Creative PCI64 (actually an Ensoniq EM1370 card). Since all three PCI slots are all possessed (sound card, display card, dvd decoder card), a vintage Intel EtherExpress 16 ISA network card is currently installed. Unfortunately, this card is neither PnP nor supported by Win2K. I’m testing the Win98 driver now.

Although I have an extra 1.6G harddisk could be fitted to this computer, I decided to do that later together with replacing ATX power supply. The hardware modification is temporerly frozen from now:) Software deployment will start from tomorrow.

Software todo:

- install original wavetable support for Creative card.

- find some piano teaching software and install.

- install cakewalk or other composer software.

- tune arcade game emulator

- make network card working under W2K

- play with OS/2 live cd

- play with DSL live cd

Later hardware todo:

- check Dxr2 TV out support for GUI display

- ATX power supply upgrade

- install second 1.6G harddisk with second OS

BTW: Surprisingly, among those popular old sound cards, Yamaha 724 is one of the best MIDI quality. The disadvantage of Ensoniq EM1370 is they didn’t open their wavetable format even the card actually support dynamic wavetable loading. That means it’s impossible to delivery new instruments by third party. What a pity! Maybe software synthesizer can resolve this problem, but I’m not sure if this K6-3D 450 machine is capable to do that.

MIDI workstation Day 1

Tonight, finally, I began to connect my Casio keyboard to the computer freshly refurbished yesterday.

The circuit is quite simple since I only need MIDI out to computer, actually the most important part is an optical coupler.  A TLP521 4pin one was salvaged from an broken fax board. This time, instead directly soldering everything together immediately, I used a prototyping board and some temporary wires to test the concept and components firstly. It works beautifully with the soundcard’s hardware synthesizer.

One big issue is, I hope to connect the joystick while I connect midi keyboard. Therefore, I am going to install another 9 pin D-sub socket on the computer shell and soldering all isolation circuit inside. That means, hopefully my computer will have a new MIDI port. The bad thing is there is no internal connector on the soundcard for MIDI port. So I have to directly solder wires from sound card.

I also found a new Creative SoundBlaster Pro PCI 64 and will replace the current ESS1868 AudioDrive for better wavetable synthesizer. To empty the PCI slot for this new card, I have to replace my original 100M pci network card with a very old Intel 8120 10M ISA network card.

Refurbished PC

Last two days I just stuck in a new project – to refurbish a vintage PC which I picked from a rubbish bin;)

After two days’ efforts, this only one desktop pc in my unit features:

-  AMD K6-II 450MHz CPU (I think it’s possible to overclock it)

- 192M SDRAM (all SDRAMs I can source at this moment)

- Creative PC-DVD Encore suite (now I can play full-screen smooth DVD no problem:)

-  USB 1.1

- Camera for video chatting

- Dual game controller (one is a vintage game pad connected to the vintage ‘game port’, another is a modified XBOX controller connected to USB)

- Internet connectivity

- Tracking ball as mouse

I’m currently running Win2K prof on this machine, and it’s smooth enough. It’s quite comfortable to surf internet with firefox 1.5. Since it’s the only computer in my unit which has two joysticks at once, it’s definitely a target platform for game emulators.  But actually the original purpose of restoring this machine is for MIDI composing.

Therefore, the next project is the pc-midi interface cable.

If I can source another ATX power supply, I will also replace the existing AT power supply for extra APM functions.

Away from radiation

the RF radiation from wifi router is always a risk. Yestoday, I managed to reduce the Tx power of my FON from 63mW to 3mW. It’s a huge reduction, but the wireless is still working fine within my apartment.

I really should do it earlier.

Digital Photo Frame

Remember that $30 laptop?

Finally, I mean after one and half month struggling, finally I got it working.

It is perhaps the longest project I did since I moved to Sydney. Almost everyday during this one and half month.

The biggest issue is the laptop itself. The cardbus support is not well compatible with my 802.11G wifi card. Initially, I tried to connect to my existing WPA encrypted wifi router. But it’s very unstable. Both cards I have, one Ralink 2500 and one Antheros 5212, crashed system immediately after driver loaded in windows. Thought maybe the support for wifi is not good in Win95OSR2 (loaded when laptop coming), I tried windows 98 and 98SE, same. Actually, before the full win98se, I installed 98lite. That’s a mistake cause it took me double time to confirm win98 did not work either.

Before giving up, I tried to install linux. Since I need a really small and fast one, The Damn Small Linux was installed, with the only boot option of floppy driver (I’m lucky to have that driver:) But latter I found DSL is not a good choice either because too many system modules and tools were missing and hard to config.

After many days and many hours experiments, finally I found the combination of Atheros card and open (no encryption) wifi link is the most stable configuration, and the madwifi driver under linux is much more stable than the OEM driver under windows. So, I simply set up another virtual open wifi link on my FON router especially for this photo frame.

everything looks fine now except sometimes the card still stop to work due to a hardware resetting error. Fortunately, it can be fixed by restart the card. A script is added to system for checking the connectivity and restart wifi card.

The wifi related issue cost me around one month. The remain part is relatively straightforward. Initially, I decided to display the photos from Flickr, but I never got the Flickr::API working due to the heavily cutted perl in dsl. Then I setup another web server with a running script which randomly copy a photo to a fixed place. The script on the client side (the frame) simply download this photo and display in regular time.

So far, it’s runing well, but there were still some practical issues: LCD will shutdown after 30 mins, the system fan and hard disk were too noisy, and shutdown/switch on was annoying too. I found a lovely tool called ‘toshset’, which can be used to switch off the fan, slow down cpu (prevent over hot), shutdown hard disk, and even setup a auto power-on based on RTC time. The suspend-to-RAM feature also works well in this old laptop. The shutdown & switch on time became much quicker by using it. The scheduled shutdown can be implemented by a tool called ‘apmsleep’.

I spent much time on the RTC auto power-on feature too. There are two issues: the ‘date’ command in linux will not automatically set the RTC. therefore, after reboot your date will be lost again. I tried to use ntpdate to syncronize with a time server, but unfortunately it did not support proxy. You need to use ‘hwclock’ to set the RTC properly. Another issue in this particular laptop is the RTC battery and sub-battery are totally dead. Those batteries are some weired model which are actually a combination of several button-sized Ni-H 30 mAh batteries. I managed to pick three working ‘button’s from the sub-battery and used as RTC battery, and it works!!

Too make a system work, even a really simple system, and easy to use is really tough. you have to overcome every possible obstocle and carefully consider every detail. What I think I did well is the overall process:

1. resolve key tech problems

2. create prototype for pilot running (always require some dirty hacks:)

3. develop production system

4. add new features

My next tasks are adding more features on this digital photo frame, such as clock, weather, tv guide, calendar, and even POS.

The $30 laptop

This is not a new UN project for developing countries.

Four weeks ago, inspired by the chumby project, I would also like to build a wifi-enabled appliance with some easy-to-use functions built-in, such as alarm clock, photo frame, scheduler, weather forecast, TV guide, etc. The best idea to do this I guess is to build the system based on a cheap laptop. Although I have an Amity VP in hand, but the 16bit wifi card was missing. Actually, the extra wifi card I have is cardbus compatible.

Luckily, I found an VERY old laptop – toshiba tecra 500cdt – from one friend, and purchased it for $30. It comes with windows 95. everything looks fine. BUT, the nightmare started from I trying to fit the cardbus 802.11g card in. The system simply crashed every time I installed driver. I spent all nights during several weeks to replace the os and try to make it working. no luck. even tried linux.

sometimes I just think that the cost of time I spent in such kind of projects has been far more expensive than the cost I saved compared to a pre-build product. so what? you can’t get the happiness that you build it by yourself anyway.

Project now suspended.

The blogs

Actually, I started many blogs in different stages before. what I repeated is just throw an old one and then start a new one, move from one system to another, or from one host to another. That’s a big mistake, since the most important thing is to keep writing but not switching.

For now, I hope I can merge all blogs together and maitain the only blog.