Samsung Galaxy S5 SM-G900T - fix "Set Warranty Bit : recovery"

November 26th, 2016 No comments

After a failed firmware upgrade, our SM-G900T refused to boot.  Its screen read:

Set Warranty Bit : recovery

Attempting to boot to download mode by pressing and holding Volume Down, Home, and Power caused the phone to reboot, but return to this screen.

The fix was to remove the battery, then press Volume Down, Home, and Power, and insert the battery while these three keys were pressed.  It took some effort to do all at the same time, but was possible.

The device then booted to download mode and we were able to use Odin to reinstall the stock firmware which we obtained from

Tests of Asterisk Proxying Audio

October 28th, 2016 Comments off

Yesterday, we wrote an article about how to remove Asterisk from the media path if NAT was involved.  Today's article focuses on why you would want to do such a thing.  The answer depends on the specifications of your project.  If your project requires Asterisk to listen for DTMF, record the call, transcode between codecs, or any other feature that involves audio processing, Asterisk will need to proxy the audio.  If that doesn't apply, here are some reasons why you might not want Asterisk to handle the audio:


Asterisk directmedia and NAT

October 27th, 2016 No comments

Recently we were vehemently told it is impossible to remove Asterisk from the media path if there is NAT involved.  Naturally, we had to find out if that was wrong.  It is absolutely possible, and here are a few ways to do it.  These observations are based on experiments with Asterisk 11.

In order for audio to travel directly to the phone, bypassing Asterisk, one of two things must happen:


We conducted 15 tests on LED bulbs and dimmers

October 13th, 2016 No comments

We conducted tests on our top five dimmable LED bulbs, two of the most popular LED dimmers, and one ridiculously hard to find electronic low voltage dimmer.

Lutron 153PLeviton 6674Leviton 6615
(ELV; requires neutral)
Philips 9.5W Warm GlowBarely perceptible buzz.  Very minor flicker between 30% and 60%Barely perceptible buzz.  Slight "whine" could be heard in a quiet room.  Very minor flicker at 30% only.  Dims up to full brightness somewhat slowly.
This is a good combination, if you can't find an ELV dimmer or you don't have a neutral.
Silent.  No flicker.
Best choice!
Feit Enhance 9.5WModerate buzz.  Very minor flicker below 33%.Moderate buzz at 33% only.  Barely perceptible buzz otherwise.  Flicker.Barely perceptible buzz.  No flicker.  ~1/2 second delay to turn on while dimmed.
Good choice, but Philips Warm Glow bulbs are cheaper and perform better.
Sunbeam/L'Image 9.9W (High CRI)Moderate buzz.  Very minor flicker between 25-50%.Moderate buzz.  Very minor flicker between 25-50%.Silent.  No flicker.  ~1 second delay to turn on while dimmed.
Good choice, if you don't mind the startup delay.
Noma 3000K 8.5WModerate buzz.  Very minor flicker below 33%.Barely perceptible buzz.  Flicker below 50%.Silent.  Very minor flicker below 33%.
Cree 4Flow 10WModerate buzz.  Flicker.Moderate buzz.  Flicker at 66% and below 33%.Silent.  Very minor flicker below 33%.

As you can see, our Lutron 153P did not perform well with any of our bulbs.  We don't usually return products to a store after damaging the packaging, but there was no other way to open it, and the dimmer didn't perform worth crap.  So, back it went.

The Leviton 6674 universal CFL/LED dimmer really only performed well with our Philips Warm Glow bulb.  It looks great.  The sound is mildly annoying in a quiet room, but if you don't have a neutral at your switch box and can't use an electronic low voltage dimmer, this is the best combination we have found.

The Leviton 6615 trailing-edge electronic low voltage dimmer performed extremely well with our Philips Warm Glow bulb, and very well with our Feit Enhance and Sunbeam bulbs.  Unfortunately this dimmer is no longer available at both Rona and Canadian Tire and we've had no success finding replacements.  If you know where to get them in Canada at a reasonable price, please let us know in the comments below.  Note: electronic low voltage is not the same as magnetic low voltage.

2016 A19 LED bulb power consumption tests

August 6th, 2016 No comments

We've always been curious if LED bulbs' power consumption is as advertised.  The answer is generally yes, with one exception that we've found so far.  Read on to see the results of our tests, and a video of our testing method.


T8 LED vs A19 LED - a lumen-for-lumen cost comparison

July 30th, 2016 No comments

If you're installing lights in a garage, storage room, or other place where the look of the physical fixture is unimportant and you just want good quality light, read on.  Today we decided to compare the cost of operating two T8 LED tubes with the cost of operating enough A19 bulbs to provide the same brightness.

5.5 Luminus A19 bulbs, total 4400 lumens (Costco)$12.38
Basic light fixtures ($1.99 box + $1.79 lampholder, Lowe's)$20.79
Initial cost$33.17
1.5 replacements$18.56
5.5*8W for 50,000 hours at $0.11/kWh$242.00
Usage cost$260.56
2 Luminus T8 LED tubes, total 4400 lumens (Costco)$26.99
Basic troffer (includes ballast, Home Depot)$54.98
Initial cost$81.97
36W for 50,000 hours at $0.11/kWh$198.00
Usage cost$198.00
Upfront savings of using inexpensive A19 bulbs$48.81
Long-term (50,000 hours) savings of using T8 tubes$13.76


We expect the cost of a 4-tube fixture to be less than double the cost of a 2-bulb fixture.  However, we were not able to find power consumption figures for this configuration.

This comparison assumes the cost of new components.  If low cost is more important than asthetics, it should be trivial to find an old T12 fixture for cheap, remove its ballast, and replace with an electronic T8 one, for less than the cost of a new troffer and ballast.

This does not consider the cost of labour to replace the A19 bulbs 1.5 times.

T8 LED and Fluorescent Cost Comparison

July 24th, 2016 No comments

Trying to decide whether to retrofit your T12 fixtures with fluorescent or LED?  Perhaps this cost comparison will help.

T8 Ballast (Westburne)$14.46
2 Philips T8 fluorescent tubes (Westburne)$6.00
Initial cost$20.46
1 set of replacement tubes$6.00
54W for 50,000 hours at $0.11/kWh$297.00
Usage cost$303.00
T8 Ballast (Westburne)$14.46
2 Luminus T8 LED tubes (Costco)$26.99
Initial cost$41.45
36W for 50,000 hours at $0.11/kWh$198.00
Usage cost$198.00
Upfront savings of using inexpensive fluorescent tubes$20.99
Long-term (50,000 hours) savings of using LED tubes$84.01

Using these numbers we can calculate the breakeven point to be approximately 7571 hours - significantly below the 50,000 hour rated lifepsan of the bulbs and ballasts.  In other words, after slightly over 15% of the components' rated lifespan, you will save money.

This does not consider the cost of labour to replace the fluorescent tubes one time.

Some guy did some great tests of 2-bulb 4' tube light power consumption

July 24th, 2016 No comments

Comparison of Philips InstantFit T8 LED and Philips T8 Fluorescent:

T12 Fluorescent:

T12 Fluorescent (2 bulbs) - 90W
T8 Fluorescent (2 bulbs) - 54W
T8 LED (2 bulbs) - 32W

Mango's 2016 A19/800lm LED Bulb Roundup

July 23rd, 2016 No comments

We decided to compare the top bulbs from the top manufacturers.  We chose candidates by looking at results from internet polls, and comparing them with bulbs easy to find at national retailers.  Our LED Bulb Reviews are elsewhere on the blog.  Here is a summary of our tests, ranked in our order of preference.  All the bulbs we tested are A19 shape, around 800 lumens, and either 2700K or 3000K.

Philips 9.5W Warm Glow
As usual, Philips' latest light bulb is in first place for our favourite.  This is a pretty great bulb that dimmed silently with a trailing-edge (ELV) dimmer or very quietly with a leading edge dimmer.  Not only did it dim smoothly with no flicker, its colour temperature dropped just like an incandescent bulb.  Barely-detectable EMI.  This bulb used to be expensive but a recent price drop makes this bulb just pennies more expensive over 10,000 hours than the Sunbeam/L'Image bulb in third place below.

Luminus 3000K 9.5W non-dimmable
This bulb's purchase price of just $2.25 (in a pack of 8 at Costco) makes it the lowest of all the bulbs on our list.  It's not dimmable, but at this price, who cares?  Its minimum operating temperature is -40C and it's suitable for damp locations, so it would make an excellent outdoor bulb.  The bulbs are instant-on and completely silent.  Light produced looks the same as the Noma bulb below.

Sunbeam/L'Image 9.9W (High CRI)
We've only seen Sunbeam-branded bulbs for sale at Costco.  This bulb's dimmer compatibility list has a short 11 models on it, but it did dim well with our trailing-edge (ELV) dimmer, even though our dimmer was not on the list.  This is one of two bulbs on our list (the above Luminus is the other) with a minimum operating temperature of -40C.  The bulb's price of $5.10 is very low for a 25,000 hour, 9.9W dimmable bulb.  Indistinguishable from incandescent.  Very low EMI.  Overall an excellent bulb if you don't mind that it's not instant-on.

Noma 810 Lumens 3000K 8.5W 25000 hr bulb
This is an excellent 3000K bulb and is the least expensive bulb over 10,000 hours that we have tested.  It looks very different from 2700K so don't expect to mix them in the same room.  Perfect for people who don't like the yellow look of soft white but also don't like the blue look of daylight bulbs.  Very low EMI.

Feit 2700K 9.5W Enhance (High CRI)
We find it difficult to visually tell the difference between 80 and 92 CRI, but our test equipment could.  It is suitable for use in fully enclosed fixtures. This excellent bulb was disappointing only in its greater-than-average electromagnetic interference.

Philips 8.5W
This bulb is only rated for an oddly specific 10,950 hours instead of 25,000+ like much of the rest of the bulbs we tested.  However, this is offset by its lower power consumption and lower purchase price.  The bulb appears slightly more red than incandescent bulbs so doesn't match perfectly, but is still pleasing to look at.  This bulb produces a barely perceptible buzz, but is imperceptible from more than a foot away.  Also has a slight flicker upon turning on, but then is flicker-free.

Cree 4Flow 11W
The is the first Cree bulb we've owned that actually looks good enough to not be relegated to our outside fixtures where we don't have to look at it often.  The electromagnetic interference it generates is still higher than its competition.  One advantage to this bulb is that it may be used in fully enclosed fixtures.  This bulb flickered when we attempted to dim it with a Leviton 6674 dimmer, despite the dimmer being on the bulb's compatibility list.  It dimmed well with our trailing-edge (ELV) dimmer.  The latest version of this bulb offers 10W power consumption (down from 11W) but its relatively high purchase price still makes it the most expensive bulb over 10,000 hours that we tested.

Philips SlimStyle 10.5W
This is the first LED bulb that we ever tested that produced good quality light for a relatively low price.  We still think it produces good quality light, and are not replacing our existing SlimStyle bulbs, but its 10.5W power consumption, poor performance with dimmers, and unusual shape, will prevent us from buying more, now that better bulbs are on the market. Coupon Code

June 5th, 2016 No comments

This is a blatant attempt to generate referral coupons for me.  If you use the following code, you and I will both receive $10 off our next order of $40 or more.



Cree makes light bulb that doesn't suck as much, green tech blogger nonplussed

December 25th, 2015 No comments

If nothing else convinces you that Mango is open-minded, this will.  It's an actual positive review for a Cree light bulb.  Well, it's not exactly a positive review, but it's not a vehemently negative review either.  Still astonishing.  We'll wait while you pick yourself up off the floor.  Then, we'll continue.

The first thing you'll notice is that Cree's new 4Flow bulb sports an interesting heat dissipation design: ventilation holes in the top and bottom of the bulb.  But, forget that.  The light produced by this bulb looks actually good.  For once, a Cree bulb won't be relegated to our outdoor fixtures where we don't have to see it much, or simply not used at all.

Light quality: Very good.  We could not tell the difference between this and an incandescent bulb.

Light quality when dimmed: Very good.  The bulb dimmed smoothly with both our Leviton 6615 (trailing edge) and MACL-153M (leading edge) dimmers.

Buzz/hum: None detectable.

Buzz/hum when dimmed: Very low.  It is unlikely the bulb would be heard in a quiet room.

RF interference: Like Cree's other bulbs, this bulb produced a mild amount of electromagnetic interference.  However, when we moved our radio several feet away, the radio worked properly.

Notes: The bulb's packaging does not prohibit its use in fully enclosed fixtures.

Price: $10.97 at Home Depot Canada.  This bulb's relatively high purchase price makes it the most expensive bulb over 10,000 hours that we have tested.

Best Buy Customer Service

December 21st, 2015 No comments

We almost never shop at Best Buy, until they have a deal that's too good to pass up.  Then we remember why we almost never shop at Best Buy, and the cycle starts over.  Most recently on Black Friday, they had a TV for 40% off that fit the exact specifications of a TV we needed for a project, so we bought it.  After many tries over half a day, we were able to check out.  Astonishingly, the TV was shipped as scheduled and arrived without incident.

Then we tried to obtain a receipt for the order, as required for our audit purposes.


Philips 9.5W Warm Glow LED Review - if you want a dimmable LED with no buzz and no flicker, read this

October 26th, 2015 No comments

Recently we worked on a project requiring dimmable LED light.  Not only did the lights need to be dimmable, but the project also had the following requirements: the bulbs and dimmer must be silent, there must be no visible flicker, and electromagnetic interference must be kept to an absolute minimum.  We tested nine bulbs from five manufacturers, on both leading and trailing edge dimmers, and the combination of Philips' 9.5W Warm Glow LED with a Leviton 6615 (trailing edge) dimmer was THE ONLY combination that satisfied all the requirements.

Light quality: Very good.  We could not tell the difference between this and an incandescent bulb.

Light quality when dimmed: Excellent.  The bulb dimmed very smoothly with no flicker using both our leading and trailing edge dimmers.  Not only that, its colour temperature changed slightly just as incandescent bulbs do.

Buzz/hum: None detectable.

Buzz/hum when dimmed, Lutron MACL-153M (leading edge) dimmer: Barely perceptible.  It is unlikely you would hear the buzz in a quiet room.

Buzz/hum when dimmed, Leviton 6615 (trailing edge) dimmer: Completely silent.

RF interference: It was difficult to detect electromagnetic interference, even with a meter.

Price: $11.98 at Home Depot Canada.

Maximum Image Size - WordPress Plugin

September 24th, 2015 No comments

Sometimes, it's not necessary to keep copies of full resolution images on your web server.  But, when you solicit images from many sources, you may not be able to rely on users to size images to your specifications.  Here's a very simple plugin that removes the full resolution image and replaces it with an image resized to your preference.

The plugin makes no changes to your database and is written with just 17 lines of code.


1) Download the plugin: Maximum Image Size
2) From with in the WordPress Admin Panel, Navigate to Plugins >> Add New >> Upload Plugin.  Upload the file you just downloaded in step 1).
3) Activate the plugin.


This plugin has no configuration.  It works based on the Large image size, a configuration option which already exists in the WordPress core.  You may configure this by navigating to Settings >> Media.

Tip: If you do not wish to retain a Medium image, set both Max Width and Max Height to 0.

I have a new hobby, and it's making ice cream

July 28th, 2015 No comments

...because that seems like a reasonable thing for a 30-year-old man to do for his hobby.

Mangosteen bought a Cuisinart ice cream maker off Kijiji some time ago, but I only tried it for the first time this week.  The verdict: heaven in a dessert cup.  I made up the recipe by myself and the result is without question the finest ice cream I've ever tasted.  It even scoops just like hard ice cream from a store.

Keep reading for the recipe used to make the ice cream shown in the picture above.


Review: 2015 Philips 60W Replacement LED

June 11th, 2015 No comments

On a recent trip to the United States, we made a special trip to Home Depot to pick up some of Philips' new 60W Replacement LED bulbs.  These bulbs don't have a special brand name like the SlimStyle does, and Philips has several 60W Replacement LEDs.  The ones we bought were the ones just released this spring, at the time on sale (USA only) for an astonishing $4.97 for a pack of two.

This bulb is incredibly affordable.  We've calculated that at its current sale price and with our use, we'll only need to use it for five weeks before it becomes cheaper than an incandescent bulb.  While we've no complaints about new technology being affordable, we hope that Philips will maintain its reputation for quality, and that cheap bulbs that last for a decade or more will be profitable.

Here's our review of the 2015 Philips 60W Replacement LED.

Light quality: Good.  We could tell the difference between this and an incandescent bulb, however, the light produced by this bulb was still pleasing.

Light quality when dimmed: Not supported.

Buzz/hum: Barely perceptible.  It is unlikely you would hear the buzz in a quiet room.

Buzz/hum when dimmed: Not supported.

RF interference: No problems detected with equipment on frequencies from 500 Mhz - 2.4Ghz.

Price: $9.97 for a pack of two at Home Depot in Canada.  Note: The per-bulb cost in some bulk packs of this product is higher than small packs.  Shop carefully.

Other notes:
- The bulb's low cost comes from its estimated 10,950 hour life and lack of support for dimmers.
- The bulbs are manufactured in China.

DIY Windshield Stone Chip Repair

March 27th, 2015 No comments

Did you know that DIYing a windshield stone chip repair is cheap and relatively easy, with results just as good as or better than the professionals?  Why spend $50 or more when you can do it yourself for 1/5 of the price?

If you can read and follow instructions, (and if you can't - look for Permatex's YouTube channel) you can repair a stone chip in your windshield - both to improve the appearance, and prevent the chip from turning into a crack.  The kit we use is the Permatex Bullseye Windshield Repair Kit.  Not only do the results look great, our oldest repair is over a year old and shows no signs of cracking.  Take a look:

On the left is the chip before repair.  In the middle is the repaired chip.  On the right is a professionally-repaired chip for comparison.  As you can see, the repair that we did reduced the appearance of the chip by two thirds or more.  With smaller chips, the repair is completely invisible.

While the product's performance is excellent, our only complaint is that there is just 0.025 fl. oz of resin included in each kit.  The included tools are all reusable (clean while still wet with acetone or rubbing alcohol) and thick and wide double-sided tape is easy to find.  If anyone knows where to buy more resin, let us know.

Convert audio files to ulaw for use with a VoIP PBX

January 21st, 2015 2 comments

Converting high quality audio files to ulaw is easy, but making them sound good takes some effort.  Keep reading for the technique we use.


Vegan perfect flat-top Pumpkin Pie

January 2nd, 2015 No comments

For years we've wanted to know how to make a pumpkin pie with a perfectly flat top.  One answer: have a kid who doesn't eat eggs or milk.

Blend 8 oz (227 g) soft tofu in a blender until very smooth, adding up to 15 oz (425 g) canned pumpkin if necessary so that the blender works properly.  Transfer to a mixing bowl along with any remaining canned pumpkin, 1/3 cup fructose, 1/3 cup maple sugar, 1 teaspoon cinnamon, 3/4 teaspoon ground ginger, 1/2 teaspoon salt, and 1/4 teaspoon ground cloves.  Use a stand or hand mixer to mix very well.  Add 2 tablespoons corn starch and mix one final time.  Pour into unbaked pie shell and bake at 350F for 45 minutes.  Cool to room temperature, then chill for at least two hours.

Variation: instead of the fructose and maple sugar, use 2/3 cup white and/or brown cane sugar.  We found the flavour of beet sugar strong enough to overpower the taste of the pumpkin.

Wired remote control for a BenQ SP831 Projector

October 31st, 2014 No comments

Recently we needed to control a digital projector outside of the IR range of its remote.  The projector and remote were both capable of connecting via a cable, but no documentation was provided on how to do so.  This is what we discovered in testing:

- The plug required is 2.5mm TRS (stereo).  TS did not work.
- Though TRS is required, only two conductors (RS) are used.
- The jack on the remote is recessed far enough that the housing of most 2.5mm plugs we tried prevented them from being plugged in.  We eventually found a mobile phone headset cable that fit.  Its hairlike wires required soldering with painstaking precision.

Due to using pre-installed and unused cable, our finished product was as follows:

Custom-built 2.5mm TRS to RCA adapter -> 50' of RCA cable -> RCA to XLR adapter -> 200' of XLR cable -> custom-built XLR to 2.5mm TRS adapter.

This project would have been significantly simpler if the remote (a) did not have a recessed jack and (b) accepted a TS cable (which would be compatible with TRS).  Since only two conductors are used, it's pointless to design a jack that demands a three-conductor plug.

Update: We discovered that the remote inexplicably stops working if it is plugged in for an indeterminate amount of time.  So, we unplug the remote when it is not in use.

Dairy-free Lemon Tapioca Pudding

October 20th, 2014 No comments

This excellent recipe is just as phenomenal as the original.

2 400 mL cans coconut milk
⅓-½ cup sugar
¼ cup quick cooking (Minute brand or similar) tapioca
1 large egg
Finely-grated rind of ½ lemon
Juice of one lemon

Combine all ingredients in a saucepan.  Beat very well, and then allow to stand for 15 minutes.  Bring to a boil over medium heat, stirring every minute or two to prevent the pudding from sticking to the bottom of the pan.  Allow to cool for 30 minutes.  Beat well before serving warm or cold.

Review: Philips SlimStyle LED Bulb

October 19th, 2014 No comments

Canada has already phased out 75- and 100-watt incandescent bulbs, with 40- and 60-watt to follow at the end of the year.  But according to a public opinion poll published on the Toronto Sun's website, 86% of respondents stated they still used incandescent light bulbs.  If this were a political blog, we would explore the topic of why the government is making a product that is used by 86% of voters difficult to buy, instead of encouraging industry to make the alternatives significantly better.  But it isn't, so we won't.

Instead, we'll talk about the new Philips SlimStyle LED bulb.  This bulb was released just this year - none too soon for those who don't care for CFLs, and who have found the performance of every other LED bulb on the market mediocre.

Light quality: Very good.  We could not tell the difference between this and an incandescent bulb.  However, the bulb looked odd in some fixtures when turned to certain angles.

Light quality when dimmed: Noticeable flicker, even though both of the dimmers we used were on the bulb's compatibility list.

Buzz/hum: None observed.

Buzz/hum when dimmed: Moderate.  The bulb could be heard in a quiet room.

RF interference: It was difficult to detect electromagnetic interference, even with a meter.

Price: $6.97 at Home Depot Canada.

More commentary follows.


Lenny, the bot that tricks telemarketers

September 15th, 2014 18 comments

Not all telemarketers are evil.  It's the 99% give the 1% a bad name.

The 99% are the telemarketers who don't respect the Do Not Call List.  Or they purchase a copy of it, and market specifically to it.  Perhaps they're exempt from respecting the DNCL, and they call people who are listed just because they can.  They run credit card or vacation scams.  They spoof their Caller ID so you think it's your neighbour calling you.  They call at 9PM and wake your kids up.

For those telemarketers, there is Lenny.  Lenny is a hilarious set of very convincing recordings designed to fool telemarketers into thinking they've called a real person.  Have a listen:

Want to talk to Lenny, or transfer/conference a telemarketer in with him?  If you use VoIP and can call a SIP URI, he can be reached at  Or you can call him at 1-347-514-7296.  (Prank calls to this number are not allowed.  Lenny is for incoming, telemarketing calls only - not for annoying innocent people.)

For plenty more recordings, visit Lenny's YouTube channel.

Download music from via the Brightcove player

September 15th, 2014 1 comment

This is our procedure for downloading music in MP3 format from CBC's Brightcove player.


Can't work with large files via WebDAV or cPanel Web Disk?  Here's the fix.

September 10th, 2014 No comments

cPanel's Web Disk uses the WebDAV protocol to allow you to manipulate files on your hosting account via Windows Explorer, just as if it were a drive letter.  The best part is that support for this is already built in to Windows.  You needn't even install any software.

By default, Windows prevents you from working with files greater than 50MB, and for longer than 30 minutes, but that can be fixed with a simple registry change.  You can make the change with Registry Editor, or copy the text below, save it as a file with the extension .reg, and run it.
Windows Registry Editor Version 5.00