Looking for the perfect car MP3 player/FM transmitter

I have bought quite a number of car MP3 player/FM transmitters from DealExtreme and other similar websites.

A car MP3 player/FM transmitter is a device that takes a SDHC memory card or a USB memory stick and plugs into the car cigarette lighter socket. It plays the MP3 files stored on the memory card/stick and transmits that as FM signal to be picked up and played by the car stereo.

It is a nifty and convenient device because not all car stereo can play MP3 files, or be able to accept a memory card or stick. Also such a device is very portable. You can simply plug it into any vehicle eg. a company car and it will play all your favorite music.

Other alternatives exist eg. bluetooth, but they are simply not as straightforward and universal as this solution. After all, you'd be hard-pressed to find a car without a cigarette lighter plug.

The perfect car MP3 player/FM transmitter should have the following characteristics/features:

1. Emits strong FM signal
2. Remembers last FM frequency used
3. Remembers last MP3 file played
4. Remembers position of last MP3 file played
5. Supports Unicode font on LCD display
6. Body of memory card should not stick out when plugged in

1 and 3 are pretty much essential for the device to be useful. Unfortunately I have had to throw at least .a few devices away right upon arrival because they were lacking one or both of these features.

2 and 4 are good-to-have features (some may even consider them essential). 2 can be overcome by setting the car stereo to the default frequency, but sometimes you need to change the default frequency on the device because of interference, and having to do that during every cold start gets old after a while.

4 should be quite easy to do (just a little extra memory to store the last play position), but surprisingly I have not seen any device that has this feature! Either there is some unknown technical barrier to implementing this feature, or Chinese manufacturers are .too stingy to spend a few more cents to do so.

5 is a nice-to-have, since none of my Mandarin songs have their ID3 displayed correctly. On the other hand, this is understandable because it will probably add a lot to the production cost to embed a Unicode font into such a tiny device.

6 is simply a design issue. Half of the devices have it right, others have the memory card sticking out so badly I wonder what the designers were thinking.

I have yet to find my perfect car MP3 player/FM transmitter. I have bought at least a dozen such devices now, and none of them have all of 1,2,3 implemented, not to mention the others. The local Chinese OEM devices sold in Oz stores are not .much better.

Anyway, if you know of the perfect car MP3 player/FM transmitter, please leave me a comment. I am willing to pay a premium for such a device, but I am tired of buying one device after another and being disappointed over and over again...

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Roomba navigation algorithm

I have been a long time user of the Roomba vacuum robot, starting from version 1 till now. It has made a big difference to my life, and I enthusiastically recommend it to all my friends.

One thing that stands Roomba apart from other vacuum robot is its navigation algorithm. There is no high-level mapping involved. Instead it uses localized decision making, much like how insects forage for food:

Our robot computes its algorithm 67 times every second, constantly stitching together information about its environment and recomputing its path. When it starts you’ll notice a spiral pattern, it’ll spiral out over a larger and larger area until it hits an object. When it finds an object, it will follow along the edge of that object for a period of time, and then it will start cris-crossing, trying to figure out the largest distance it can go without hitting another object, and that’s helping it figure out how large the space is, but if it goes for too long a period of time without hitting a wall, it’s going to start spiraling again, because it figures it’s in a wide open space, and it’s constantly calculating and figuring that out. It’s similar with the dirt sensors underneath, when one of those sensors gets tripped it changes its behaviors to cover that area. It will then go off in search of another dirty area in a straight path. The way that these different patterns pile on to each other as they go, we know that that is the most effective way to cover a room. The patterns that we chose and how the algorithm was originally developed was based off of behavior-based algorithms born out of MIT studying animals and how they go about searching areas for food. When you look at how ants and bees go out and they search areas, these kinds of coverage and figuring all of that out comes from that research. It’s not exact, obviously, I’m not saying we’re honeybees, but it’s that understanding of how to search out an area in nature that is the basis behind how our adaptive technology is developed.

The algorithm is actually quite effective and robust in the real world. For a short while, I used to house two cats in a room, and you can imagine how dusty that was. Roomba never failed to clean up the room for me after I left it to its devices. It was squeaky clean after each session, and all I had to do after that was to give the wooden floor a quick mop.

Don't take my word for it. Check out this video providing a time-lapsed coverage test of various vacuum robots, including The Roomba 5 series.

However, I never fail to notice, both online and off, how Roomba's navigation algorithm invokes all kinds of negative feeling in users. Comments typically are of the types:

... It is just going in random directions
... Personally I will not vacuum like that
... Why does it go over the same area twice?
... It is not very efficient, it takes too long 

I have seen people just standing there and supervising/criticizing their robot's every move! This is crazy! Do you stand there and supervise your washing machine? I mean, you just dump your clothes in, set a wash cycle, and come back in 45 mins or whatever. What's so difficult about that? Instead you have people just hanging around and second guessing every move the robot makes. Absurd!

I can understand maybe a robot vacuum cleaner is something new to a lot of people, it hasn't become quite as mundane as a washing machine. Or maybe a localized or bottom up algorithm is just harder to understand/accept compared to a top-down algorithm. Rodney Brooks, the co-founder of iRobot, the company that makes Roomba, is a pioneer in the field of bottom-up robotics. He famously created robotic insects that do not have a central "brain", but instead make localized decisions based on the feedback from various sensors (much like the Roomba). In the physical world, that approach turns out to be extremely robust and resilient.

AFAIK iRobot has never organized any campaign to dispel such negativity. I guess maybe it is just too difficult and technical to make people understand that a bottom-up approach is superior to a top-down (mapping) approach. I hope I can make a small difference by blogging about this here. Roomba's navigation algorithm in the real world is robust. You can move furniture around while the robot is running and not have to worry that it won't come back again. You can let it bump into your foot if you are doing stuff in the same room while it is running, but you can be assured that will not have a large impact on what it is doing.

You don't want a robot to vacuum like you do. Otherwise, cars will have legs, and washing machines will have arms. Just clear the room, set the robot down, let it run, grab a cuppa and come back an hour later. The room will be clean. Trust me.

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Yield comparison on toner cartridges/refills

Following my initial encounter with the starter toner cartridge on the Brother Hl-2132 laser printer, I have been experimenting with different toner cartridges/refills and noting the cost/yield with each method.

I bought an OEM high yield toner cartridge for $32 (excludes shipping) that claims a yield of 2600 pages. That only gave me 870 pages of actual output at about 30% coverage. The toner is also a little too light for my liking.

Then I bought a toner refill set for $47. All-in-all, I got about 600g worth of toner, even an accessory kit to convert the starter cartridge to high-yield cartridge (which I have not tried yet, but it looks easy enough). After viewing a few YouTube tutorials about the process, I set about putting 100g of toner into the empty toner cartridge.

It was surprisingly easy, much easier than filling up ink cartridges. The cap on the OEM cartridge was a snap to pop off and replace, and to my surprise, the cartridge worked flawlessly after I refilled the toner. The printout was very dark and nice, much nicer than the original toner that came with the cartridge!

And even better, the 100g of toner lasted a whopping 1200+ pages! Two subsequent refills gave me roughly the same yield at the same 30% coverage. Dividing the original cost of $47 by 5 refills (conservatively), it's like getting a new toner cartridge for $9 each time!

Update:

I discovered that for about $50, I am able to buy 1kg worth of toner over eBay, shipped from US. This is double the amount of toner for about the same price. So now I am getting a brand new high yield toner cartridge for $5 every time. It's crazy cheap! I am extremely happy with the result.

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Brother HL-2132 - Lousy Yield on the Starter Toner Cartridge and How to Work Around it

I bought a Brother HL-2132 mono laser printer from Offceworks recently. Like almost all printers these days, it came with a "starter" toner cartridge that promises 700 pages of print. Well, guess what? The "Replace toner" LED came on after printing only 199 pages! How do I know? More on that later.

A quick search found a number of proposed solutions on the Web, ranging from taping the optical window to resetting the flag gear on the toner cartridge. Well, the starter cartridge I got came with neither of these mechanisms. Seems like Brother has read all these solutions and decided to lock down their starter cartridges even further!

What finally worked for me was to factory reset the printer. This can be done by the following steps:

1. Open the front cover and remove the toner cartridge. Leave the front cover open!

2. Turn the printer off.

3. Press and hold the "Go" button while turning the printer on. All LEDs will light up. Release the "Go" button.

4. Now press the "Go" button twice and pause for a second.

5. Press the "Go" button a further 5 times.

6. If you have done all the above steps correctly, the computer connecting to the printer will detect a new device, try to install a device driver for it and fails, then displays an error window saying that it is unable to install a driver for the printer in "maintenance mode".

7. Now turn off the printer.

8. Re-insert the starter toner cartridge and close the front cover.

9. Turn on the printer.

After the brief startup churn, the printer was ready for printing again, with the toner level restored to 100%!

To check the toner level, right-click on the printer icon and select "Print Preferences":

Then click on the "Support" button on the bottom-left:

 Finally, click "Print Settings":

The printer will print out a single sheet of information detailing interesting tidbits such as the number of pages you have printed, the % of toner left, and the % of drum life left. That was how I got to know that the starter toner cartridge "ran out" at exactly 199 pages!

Update: I managed to get to 329 pages before the print started fading. So that's only about 100 pages more from the starter toner. To be fair, my average coverage per page is probably about 30% rather than the 5% frequently used in industrial figures, so your mileage may vary.

Further update: Yield comparison on toner cartridges/refills

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Speed comparison of USB 2.0 vs USB 3.0 portable hard drive

Here are the CrystalDiskMark numbers of a USB 2.0 portable drive (Samsung G2 Portable 640GB):

and a USB 3.0 portable drive (Seagate Expansion 750GB):

So although the theoretical bandwidth of the USB 3.0 interface is much higher compared to USB 2.0 (48MB/s vs 480MB/s), it is limited by the throughput of the mechanical hard drive. So at best you are looking at a 2x throughput improvement when moving to USB 3.0 for mechanical disks.

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Performance of SATA-to-SATA HDD caddy

The CrystalDiskMark figures for the Cosair CSSD-F80GBP2 running in the slightly reengineered HDD caddy purchased from DealExtreme is as follows:

Not top-of-the-line, but very good for running virtual machines without being bogged down by the mechanical HDD.

Compared that to the Seagate ST9500420ASG, which is a 7200rpm unit that is probably pushing the performance limits of consumer-grade mechanical HDDs:

The 4K read/write performance of the SSD gives it the extra edge when running multiple VMs on the same machine.

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Thinkpad Edge E530 won't wake up from sleep

I recently purchased a Thinkpad Edge E530 laptop from Lenovo. I think it is great value. I ordered it with the default 2GB RAM and bumped it up to a nice pair of Kingston HyperX 4GB DDR3 RAM, bringing the total up to 8GB. The whole thing costs me only about S$600.

But there was only one problem with the laptop. It wouldn't wake up from sleep or hibernate properly. I have to force power off the machine and boot it up again after sleep. I tried everything. Updating the BIOS. Updating the drivers. Nothing worked. It was frustrating.

After a tedious round of elimination testing, the culprit was finally tracked down to a HDD caddy that I purchased from DealExtreme. This is one of those gadgets that lets you install another harddisk into your space-scarce laptop by using the slot reserved for the optical drive. I use it to add a 120GB SSD drive into the laptop and use it to run certain I/O intensive applications (eg. virtual machines).

As luck would have it, I chanced upon a discussion in NotebookReview.com that talks about this issue on another laptop (but also involves a HDD caddy). I am not particularly knowledgeable about the hardware details, but apparently one of the pins (diagnostic SATA pin) is wrongly connected to ground and needs to be disconnected.

I am not very good with the soldering iron, and anyway the pads are spaced too closely together for my meager soldering skill. So armed with a small tweezer and a sewing needle, I set about trying to destroy the pin in question. Thankfully the pin itself is rather thin, so it didn't take long. A couple of minutes later, I had a clean break.

I put everything back together and powered on the laptop. Taking in a deep breath, I click on "Sleep". Hurray! The red LED on the laptop started to pulse, which indicates it is sleeping. Pressing the power button brought the laptop back to life, just as it was intended to. I couldn't be happier! Thanks to the wonderful folks who shared this piece of knowledge!

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How to build your own laptop

Ever wanted to build your own laptop?  What about mod'ing your existing laptop?  These are the kinds of questions that keep me up at night (among others.)  I did a little checking this morning, and with minimal effort I found some really fascinating stuff.  I probably have some advantage based on the fact that I've done my share of maintenance on various laptops, but I think that almost anyone could reasonably do this...

So, what do you need?  I'll do a run-down on the "major components", but I'm really only going to spend much time on the ones that are more difficult to find.

Core components:

1. Base-kit -- this is, by-far, the hardest piece to find in all of this, and certainly the most critical.  These will typically include the mother board, power-supply, battery, display, keyboard and pointer, as well as all the chassis plastics. This is going to predicate most of your selections below.
2. Video card -- incidentally, nVidia and Radeon both make some fairly glorious mobile graphics processors.  As such, these are pretty-easy to find on-line.
3. Hard disk -- your disk space.  Duh!
4. cd/dvd/bluray drive -- one beauty of building your own is that you don't even have to if you're hard-core, you may not even need such a thing (or you may want to use an external drive), but these are not difficult to find either.
5. Wireless card -- sometimes these are integrated into the mother board, but a lot of times its a module you have to add.  These are fairly trivial to find on-line.
6. CPU -- the base-kit is going to predicate which CPU form-factor you can support, but these are easy enough to find on-line.
7. Memory -- the base-kit, again, is going to predicate type and quantity.

So, lets talk about the base-kit, because there's a lot of variation with these.  While there are some really crap chassis out there, I don't think that's a governing feature; for the most part, your base-kit is getting you two big things: the motherboard and the display.

The display is fairly straight-forward: you want to get the highest resolution display you can, in the size you want.  Unfortunately you need a magic decoder-ring to understand the display-names and how they relate to features and resolution.  There is a Wikipedia page that decodes these code-names and translates them to features.  Since this is bundled in the base-kit, I'd settle on a lesser display if I got a mother board with all the features I wanted.

The motherboard is the pre-eminent component that governs all other aspects of your build.  I'll go so far as to say that the number-one requirement for any mother board is that it support an independent video card... this ensures that you'll not get a crap graphics solution.  Everything else, for the most part, is a balancing act.  You want to get a mother board that support your CPU of choice, as well as the amount of memory you want/need.  After that, all other features come in to play, such as its expansion slots, card-slots, etc.  For my money, the big-three are maximum CPU support, quantity of memory, and support for an independent video card. 

There are some big players in the base-kit market, most notably MSI.  There are some others that provide good info too, such as Directron, but I didn't look at any of the primary suppliers from China, India or Taiwan, so I know there are a LOT more out there. 

Simply put, I think you'll find its not too difficult to scrounge-up the parts, so why not build your own laptop?  I'll tell you why: warranty.  While the majority of your components will come with a 90-day or 1-year warranty, you won't get any sort of extended or 3-year warranty, and as someone who's had four laptops in the last three years, I can tell you that an extended warranty is a good idea if you do a lot of mobile computing -- for me, I've gone through so many laptops because I carry it with me all the time and routinely work at between two and four sites each day -- including putting my laptop in my backpack, putting it in my car, etc... my laptops get a LOT of wear and tear, probably more than the average user.

Anywho, hopefully this is some help.

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