Category Archives: Electronics

HTC Windows Phone 8X is a mess on T-Mobile

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I purchased the HTC HD7 shortly after it came out so I develop for a phone in a language I knew. Out the gate, the WP7 phone had Bluetooth issues, but these were largely fixed with the Mango update. So despite the big crack in the screen, I was happy with my Windows 7 Phone.

Two years later, and contract renewal time arrives – along with the release of the Windows Phone 8 platform. Time to upgrade! WP8 should be at least as good as WP7, right?

… Wrong.

At present T-Mobile has two Windows Phone 8 options – the HTC 8X, and the Nokia Lumia 810. The lumia wins hands-down in most categories – it includes navigation, has expandable storage, has a replaceable battery. But it is ugly, clunky, has a low resolution screen, and poor battery life.

So if you want a “nice” phone you are left with the HTC 8X – which is good enough for Gwen Stefani, so it should be pretty good, right?
Right?

Wrong. It is plagued by bugs and software ommisions, and HTC is dragging their feet to fix.

1. There is no turn-by-turn navigation.
Microsoft removed the turn-by-turn directions / navigation feature from bing maps, with the idea that nokia would pick up the slack. Despite reading that Nokia opened up Nokia Drive to all WP8 devices, this phone doesn’t have it. There is no navigation. There are no turn-by-turn directions. You can get directions in a list, but they are not suited to use while driving. I have been thrown back into the pre-GPS days, and it isn’t pleasant…
2. Internet Sharing is buggy
This may be T-Mobile specific, but for the first week after activating the phone, Internet Sharing didn’t work, claiming I had to “upsell” to a $15/month extra tethering plan. Not true – the $35/month 5-gig plan I have includes tethering. This phone likes to err on the side of “no soup for you,” and for whatever reason assumes you are not authorized to share your internet half the time. Real annoying, and a real step backwards = the HD7 never rejected me, even using a grandfathered 2-gig plan.
3. Bluetooth is a travesty of bugs and incompatibility.
It seem that HTC has real problems with Bluetooth on Windows phones. This thing cannot maintain a reliable handsfree connection for more than maybe 15 minutes before the sound cuts out. Everything appears to still be connected and working, but there is no sound. You’ll be talking, an all of a sudden – silence. You must disable the Bluetooth to resume your conversation.
The A2DP (music) profile doesn’t do this, but the phone locks up entirely for a good minute after the music connection is established. I don’t know what it’s doing, but after connecting for music in my car, there is silence for a minute, and the phone will not respond to input (although the windows button still causes haptic feedback). When it does finally unlock, it responds to all your keypresses in one batch, which is pretty annoying in is self (for example, if you held down the home button trying to wake it up and pressed the power button, when it does wake up you will be prompted for a voice command as well as a “slide down to turn off”) The Bluetooth is practically unusable in this state.
3a. While the Bluetooth technically “can” support serial and PAN, this is not supported by the OS as must be implemented on an app-by-app basis. Meaning no Toyota Entune (without significant effort my Toyota), no Bluetooth tethering. This is ridiculous. All developers shouldn’t have to implement portions of the Bluetooth stack, it should be is a shared library… oh wait, Windows phone apps cannot include or use shared libraries.
4. Custom Roms may be impossible (This applies to Windows RT as well). Microsoft was wise to require the use of a standardized boot method – the phones use a UEFI bootloader. That is awesome. What is not awesome: Microsoft requires SecureBoot be used to require roms be signed by Microsoft or the manufacturer, and does not provide the user the ability to import trusted keys. Windows phones (and rt devices) could have been the future of mobile computing – the ability to dual boot as easily as a PC – but greed and paranoia ruined it for everybody. Now we must hope that some hacker find an exploit to SecureBoot that will allow malicious software… in addition to the freedom to run what you want. Really stupid move from Microsoft.

Some of these issues can be resolved by HTC with firmware updates – and likely will in time. Others will require Microsoft to get off the pedestal of greed – and who knows when or if this will happen.

Till then, I may be stuck sharing my internet with an android device to accomplish what I need. Or I could jailbreak an iPhone to get what I need. How long till I tire of waiting… who knows.

On using a light bulb as a current limiter (and crude current meter)

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If you search on Google for “light bulb current limiter” you should come across several articles, newsgroup and forum posts about the details of building one. (i.e. )

Essentially, you connect a incandescent light bulb in series with an outlet, so you can safely test a device that might be prone to blow a breaker, or draw so much current as to release magic smoke.

One common feature of many of these articles is the idea that the light bulb will “blow” if the device draws too much current. This is totally and completely false.

When a 60-watt light bulb is connected directly to mains, it will draw approximately 60-watts of power, or 500 milliamps at 120-volts. That is the maximum amount of power that it will permit to flow, and it will burn at full brightness.

When you connect a device in series with the light bulb, it is effectively acting as a resistor to the current through the light bulb. With a 60-watt bulb, a device that used 250-milliamps wired in series would cause the bulb to burn at about 50% brightness (although light bulb brightness as a function of current is non-linear so this is not entired true, this is just an example…)
Now let’s imagine a worst case scenario – what could be wrong with an electrical appliance that would cause it to draw the maximum amount of current? Why shorting the power cord of course.

If you short the power cord of a device attached in series with a light bulb, the circuit is 100% IDENTICAL to plugging the light bulb directly into the wall. Nothing blows up, nothing catches fire – the bulb limits the circuit to 60-watts.

So if you are testing an electrical device using a lightbulb current limiter, please be aware: the bulb will not stop the power if too much is used. It is up to you to know how much power your device should be using, selecting a light bulb of the correct wattage to prevent it from going above (or much above) this, and turning off the power if the bulb is burning at full brightness when it should not be.

Cordless Power Tools

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Cordless power tools have the ability to be incredibly useful. Having a drill and a saw with no cord that you can take were you please and use as you please… especially in our house of few electrical outlets, these tools are amazing.

I was hasitant to invest in battery operated tools at first, however, for experience had shown me that the batteries liked to fail. My father’s cordless tools didn’t last more than a year or two before the batteries were shot. And those batteries often cost upwards of $60 to replace. It’s just obscene! They seem to be built to fail, then cost far more than the sum of their obsolete, NiCad parts. What’s the deal?

First things first, most people have a little better luck than my father. Often the batteries can last for about 2 years of occasional use before they stop holding a charge. Interestingly enough, most people don’t leave the batteries in the charger 24×7. Therein lies my father’s mistake.

For some odd reason, these cordless power tools usually come with the simplest charger possible: A wall transformer that connects directly to the battery terminals, constantly charging while the battery is connected. Sometimes there is a little indicator light to let you know it is charging.

Let it be known that these chargers will destroy batteries.

The true killer of these batteries is overcharging. To understand this, lets take a look inside the battery.
While a battery discharges, a chemical reaction occurs involving metals, oxides and ions. The reaction is always happening slowly within the cell, but it goes much faster when current is allowed to flow across the cell. Once the metals are depleted (or are getting close to being depleted), the battey stops working and the reaction is reversed. By applying a voltage to the cell, the metals begin returning to their original status. This can only continue so long as there are chemicals in their discharged state. Once the cell is fully charged, if the electricity continues to be applied, something bad starts happening. The metals are in water containing electrolyte. If you have ever seen what happens when you run electricity through water, you know where this is headed. Electrolysis begins happening to the water – breaking it down into Hydrogen and oxygen and creating large amounts of heat. Now the battery has gas bubbles – steam, hydrogen and oxygen. All modern batteries are designed to deal with this and have gas vents; however this process is what destroys the battery. A battery that is never charged to the point of elecrolysis will last a much longer time.

Since we have no way of knowing the state of the battery’s charge, we cannot know precicely when to get that battery off the charger when using the supplied charger. So what is a reasonable person to do? Some high-end manufacturers (bosch, delta) sell quick chargers that ensure battery safety. But if you’re like me, you have a craftsman, or coleman, or Black & Decker tool and there is no intelligent charger. And for that matter, the quick chargers run near $100.

There is hope. for less than $20, you can purchase the components necessary to turn your current charger into an intelligent charger that charges fast, stops when the battery is fully charged, then “trickle” charges the battery to safely maintain a full charge. (Trickle charging essentially applies current to the battery at the same rate it loses power when sitting. Thus there is no electrolysis, no overcharging.)

Would you like to know how? Stay tuned.