I’ve become fond of — maybe addicted to — ES File Explorer on my Android phones. It allows me to quickly manage folders, files, drive space, etc. I wrote a gushing article about it in early 2014. However, the latest version (v 4.5) is a mess. Apparently the company changed ownership last year, and we now see the new owners’ values. It’s an old story in computer software: the original developer carefully perfects his baby ’til he sells it, then the new (often clueless) owner tries to cash in and ruins the product.
I’ve stored earlier versions of ES File Explorer apk files that you may download and install:
Version 18.104.22.168 is a rock solid release of ES File Explorer from early 2015. It’s my favorite version. Its older user interface requires fewer keystrokes than the newer user interface.
If you’d like, you can try the newer version 4.05. It has a new user interface, but hasn’t yet devolved to the awful state of version 4.5.
To install either of these apks, you’ll need to go to your device’s Settings / Security screen and temporarily allow installation of applications from unknown sources.
(Originally published December 9, 2015) Last week, without warning, my Samsung SGH-T399 Galaxy Light phone from T-mobile began to download and update its system software to version T399UVUAOH2. Stagefright Detector now reports that my phone is no longer vulnerable to the Stagefright virus.
My phone’s About screen reports that its Android operating system remains at version 4.2.2 (Jelly Bean), but its kernel is now dated August 25, 2015 (Korean standard time).
Tip: If your Android phone is vulnerable to the Stagefright virus, you can reduce (but not eliminate) its vulnerability by, within the Messaging app, turning off the Auto retrieve setting. The Stagefright virus arrives within an SMS (short message service) multimedia message, so if your phone is vulnerable, you do not want to download these messages.
Update, February 27, 2016: T-Mobile again updated my T-399 phone. It still reports Android version 4.2.2, but now reports baseband version T399UVUAPA1 and is dated January 4th, 2016, 20:32, Korean Standard Time. According to T-Mobile’s note that accompanied the update, it improves voice over LTE (VoLTE) and unspecified security features.
Are you confused by the FBI vs Apple dispute regarding Syed Farook’s iPhone? I am.
In an excellent article published today, Cnet neatly summarized the delicate position in which Apple finds itself, following the issuance of a court order that compels Apple to help authorities unlock the iPhone 5c that was used by Islamic terrorist and mass murderer Syed Farook.
The nugget that surprises me is that the FBI appears to be preparing a brute force attack on this iPhone’s 256-bit AES encryption. This is a daunting task. To brute-force attack encrypted data that’s encrypted with AES-256, you need to try each of 2256 or 116,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000 possibilities. That’s more than the number of atoms in the universe.
If Farook chose a strong passphrase, it could require thousands of years for most computers to decrypt his data. It appears that the FBI has serious horsepower to throw at this task.
Last week, my Samsung Galaxy Light SGH-T399 phone with Android 4.2.2 stopped responding to orientation changes. When I rotated the phone from vertical (“portrait”) to horizontal (“landscape”), the display no longer rotated accordingly. In vain I clicked on the Screen rotation button.
I feared that I’d physically broken the orientation sensor when I dropped the phone the previous day. I loaded a rotation app, but found that it was a pain to use. Eventually I discovered (thanks, Google) that by typing an odd sequence of keys, I could peek beneath the operating system and directly examine the data streams from the sensors. When I did this, the phone’s screen rotation function returned.
Run the phone app, which displays the dial screen.
In sequence, press the *#0*# buttons on the dial screen.
A hardware test screen with 14 buttons should appear.
Tap the Sensor button
You’ll see the numeric outputs of the Accelerometer, Proximity, and Magnetic sensors
Press the IMAGE TEST and Graph buttons for the Accelerometer. The displays should respond to movement of the phone.
I just realized that I’ve not described how I listen to podcasts, recorded audio, and live radio broadcasts on my phone.
My first streaming audio experience was in 2000 with the Windows-based MP3 player program called Winamp. Its Shoutcast network of streaming sites is built upon the traditional broadcast model: content on each channel is delivered in a continuous stream. A listener may not demand or replay any content. There are (or were) thousands of Shoutcast channels. I still occasionally listen to Shoutcast streams on my phone using Winamp for Android (which may no longer be available). I wrote an article or two about Winamp’s latter day rough sledding.
Content on demand
I began listening to both live and pre-recorded audio with an older version of TuneIn. Its creator sold TuneIn to a company that has ruined it with too many ads and unnecessary “features”. I’ve stored an early version for Android. This older version is much better than the new version that’s available in the Android Play Store. If you have an Android device, feel free to download and install my version.
When Tunein began to degrade, I turned to Podcast Addict on my Android phone. It’s very flexible, and its many options can intimidate a first-time user. Have patience. Its power is worth climbing the learning curve. I now use Podcast Addict for most of my phone-based audio listening.
Tip: If one of these programs responds slowly, go to Android Settings, More, Application management. Select the sluggish program. Press the Force stop button. Press the Clear Cache button. Restart the program.
When you want to read an article but don’t have time to sit down and read every word, have your phone’s @Voice Aloud Reader text-to-voice app read the article aloud to you.
First, display the article on your phone (probably in a web browser). Press the Share button or icon, and choose the @Voice Aloud Reader. Allow a few seconds for the @Voice Aloud Reader app to start, load the article’s text, and begin reading.
On my Android 4.2.2 phone, the female voice is remarkably clear. It tends toward a monotone, and occasionally messes up (especially abbreviations), but is quite listenable. Within the @Voice Aloud Reader app, you can pause, rewind, etc., the reader.
Just plug in your earbuds, start up the @Voice Aloud Reader, and go!
Obviously, when your phone’s GPS receiver is on, your location within 30 feet or so is usually available.
There’s another way that remotes, your cellular service provider, 9-1-1 call centers [also known as Public Safety Answering Points (PSAPs)], and law enforcement can determine your phone’s location, even when your GPS is off, or even if your plain-Jane flip-phone has no GPS receiver. It’s called Uplink-Time Difference of Arrival U-TDOA). Here’s a brief simplified video description. Each cell tower has an antenna array with three or four 90 or 120 degree (when viewed from above) antenna sectors. Each tower knows, by comparing your phone’s received signal strength in each sector, which sector your phone is in. By measuring the propagation time for a “ping” to travel between the tower, your phone, and back again, it also knows the range to your phone. In a populated area your phone is likely to be talking with more than one tower, so all that’s needed is to know the bearing and range to your phone relative to two or more towers, and your location can be estimated within maybe a 100 foot radius. (You will be at the intersection of the two or more arcs.)
Even with only one tower talking to your phone, it knows that you are located somewhere along that 90 or 120 degree arc within the sector with the strongest signal. U-TDOA is used in Enhanced 9-1-1 Phase II systems so that first responders may be dispatched to wherever your cell phone is located when you place a 911 call for emergency assistance.
The only way to stop this is to remove the battery from your phone. (Oops. Sorry, iPhone users.) Switching it off won’t stop the communication. Switching it to Airplane Mode will prolly stop it, but there are no guarantees.
I drowned my three month old Samsung SGH-T399 Galaxy Light phone. It slipped into my bath water as I was using it in the tub. I quickly rescued it, yanked out its battery, SIM card, and SD card, and tucked it into a nice dry bed of uncooked white rice for the night. In the morning it started normally, but its display flickered and failed after warming up.
I purchased a replacement SGH-T399 phone and installed my favorite apps on it. My Google Mail contacts were restored, but the remaining contacts were not restored. By moving quickly, I was able to go to the Contacts app on the old phone and export them to a contacts.vcf file. Then I used a USB cable to make the old phone a slave to a Windows 7 PC host. I copied the contacts.vcf file to the host PC’s store. (The contacts.vcf file is located in the phone’s /storage/emulated/0/ folder.)
Then I removed the old phone from the USB cable, and replaced it with the new phone. Next I copied the contacts.vcf file from the PC’s store to the /storage/emulated/0/ folder on the new phone, ran its Contacts app, and imported contacts.vcf. Done!
My new phone now has the contacts from my old phone. Both phones run Android 4.2.2.
I discovered a method of freeing storage space on my Samsung SGH-T399 Android phone. Podcasts had stopped streaming, probably because the phone had run out of free storage space for caching. How could I create free storage space? I learned that the hidden /mnt/sdcard/.face folder had grown to 2.65 gigabytes and contained 67,000 files(!). I gambled that the facial recognition files contained there were nonessential.
I deleted the /mnt/sdcard/.face folder, then created a new empty /mnt/sdcard/.face folder. Suddenly the phone had 2.65 GB of free storage. Yesssss!
I used a terrific Android app, ES File Explorer, to discover this bloated folder, delete it, and create a new empty one. Its SD Card Analyst tool displays folders sorted in descending order by size. The .face folder was at the top of the list.
Note that the folder named sdcard isn’t actually the physical sdcard. For some reason, Samsung’s Android file system calls this phone’s internal storage folder /mnt/sdcard. The physical sdcard is named /mnt/extSdCard.
About a year ago, I wrote an article about my attempts to locate T-mobile’s nearby cell sites. I’m still having difficulty. I’ve tried several Android apps that measure signal field strength, with varying success. I’ve had the best results with OpenSignal 2.0 (available free from the Android Play Store). This YouTube video is a good introduction to the app.
OpenSignal seems to do a good job of measuring signal strength and data transmission speed. However, its estimates of cell sites’ locations aren’t at all accurate. I think that it relies upon its own database of cell sites’ geographical coordinates — and these data are inaccurate. It’s frustrating, because everything else about OpenSignal works nicely.
Most of OpenSignal’s many features work well. It has the polished feel of a good commercial app. I gather that OpenSignal regularly updates their cell sites location database, so there’s hope. In the meantime, I give it four out of five stars.
My trusty Samsung SGH-T679 phone stopped accepting touch input last Friday. I replaced it with a Samsung Galaxy Light 4G LTE SGH-T399 for T-Mobile phone. Like the T-679, it’s small and lightweight, but it’s much more powerful. T-Mobile is discounting them for $99, unsubsidized. At this low price, I didn’t expect such a great phone.
The phone’s performance is amazing. Apparently it has a quad-core CPU with separate GPU, 1 gigabyte of RAM, and 8 gigabytes of storage. It includes a slot for an SD card. The phone is fast and smooth. Its operating system is Android 4.2.2, which includes many refinements. Its email client — in fact, everything — allows more tweaking than my old SGH-T679 did.
The radios include LTE (true 4G), 802.11n WiFi, Bluetooth 4.0, and NFC (near field communication). Ookla SpeedTest reported 14 Mbps download speed while connected via LTE with a signal strength of about -100 dBm. I’ve seen download speeds of 29 Mbps via LTE with stronger signals.
While listening to a podcast on my Samsung mobile phone via the Tunein app, a pop-up announced, “Charging paused. Battery temperature too low or too high.” The pop-up remained on screen until I unplugged the charger. The battery had only about a 6% charge, so as soon as I unplugged the charger, another pop-up warned that the battery needed to be charged. Catch 22. Room temperature was probably about 77 degrees Fahrenheit.
I grabbed a cold pack from the freezer and rested the phone on its icy carcass. The over-temperature warnings ceased while I simultaneously listened to the podcast and charged the phone’s battery.
Decades ago, I helped develop military radio communication hardware. The products needed to pass environmental tests for vibration, shock, high and low ambient temperatures, and humidity — while under continuous full-load conditions. We invested many hours in heat management.
My mobile phone is clearly incapable of passing such tests. It’s intended for intermittent use — what’s known as low duty cycle usage. I’d guess that my phone can handle about a 10 to 15 percent duty cycle at full output.
This is probably as good as we can expect from consumer-grade products. We just need to have frigid cold packs ready if we want more.
My phone: Samsung SGH-T679. T-Mobile Insight II 4G.
Occasionally my Samsung Insight II phone (SGH-T679 running Android Gingerbread 2.3.6) quits communicating via IP with Internet hosts. Often, a wireless connection to a T-Mobile tower exists but there’s just no IP communication. Also, occasionally my phone insists that it can only establish a (low speed, perhaps 50 kbps) EDGE wireless connection to the tower; it refuses to connect at higher speeds (such as UMTS, HSDPA, or LTE).
A simple fix — short of shutting down and restarting the phone or system troubleshooting — is to temporarily place the phone in Airplane Mode (which shuts down its wireless radio transceivers) and then turn off its Airplane Mode (which starts its wireless radio transceivers). Your phone should connect to the cell site with the strongest signal — which may be different than the site that it was connected to before. Nine times out of ten this works for me.
While watching a Youtube video clip about the recovery of a stolen bicycle, I learned about Burner, a smartphone app that allows a smartphone user to temporarily mask his or her phone number with an alias phone number. It’s available for iPhones, but not yet for Android phones. (originally published on 31 December 2012. 9 July 2014: Burner is now available for Android phones, as well as IOS.)
Theft recovery seems like a perfect use for telephone anonymity. The victim, who’s a Portland, Oregon resident, responded to a Seattle Craigslist for sale ad for what seemed to be his stolen bike. He used Burner to make his phone calls appear to originate in Seattle.
Are you ever late for appointments? When traveling to rendezvous with someone, you may now use Glympse.com to keep your friend or business contact apprised of your geographical progress. Portable apps for IOS, Android, and Windows Phone smartphones are available.
Your friend / business contact (and no one else) will be able to track you from any Internet-connected web browser as you approach your rendezvous point. You can also periodically securely share your location via email, SMS text messaging, Facebook, or Twitter.
Occasionally, for no apparent reason, my Android phone refuses to accept a battery charge. (originally published 15 February 2014)
Here’s the only way I’ve found to fix this problem on my Samsung Insight II SGH-T679 with Android 2.3.6 Gingerbread phone:
Turn off phone
Remove SIM card
Remove SD card
Wait at least 3 minutes. (I’ve had to wait as long as 60 minutes.)
Replace SD card
Replace SIM card
Turn on phone
Plug in charger
This reset procedure works for me. It may or may not work for you. (8 Oct 2014) It also works for my new SGH-T399 phone.
7 August 2014 This may or may not be a coincidence, but I’ve found that since abandoning third-party battery chargers and returning to a Samsung manufactured charger, my phone’s battery behaves better, without loss of charging function.
I’ve also stopped buying third-party batteries. They’ve been short-lived. I found what seems to be a genuine Samsung battery on Amazon. The combination of genuine Samsung battery and Samsung battery charger seems to provide both longer battery discharge times and better charging behavior.
I’ve not needed to resort to the charging system reset procedure since installing the genuine Samsung battery and using the genuine Samsung charger.
Colin Berkshire just published an excellent article about the fat profits that are enjoyed by U.S. cellular phone service providers. His cost estimates seem reasonable, yet they amount to only two percent of revenue. He asks,
So where does all of the money go?
The only answer I can come up with as I pour through their financials is that the cell phone business is so poorly managed that there may as well not be any management. Large bureaucracy, corporate palace headquarters buildings, lots and lots and lots of executives, and a broken business model are what you are really paying for.
Because Verizon and AT&T are essentially an oligopoly (often matching each others’ prices and structures nearly perfectly) there is little competition, no need for efficiency, and no need to build lots of pesky towers.
My Android phone was running out of free storage space. I discovered that the phone’s /mnt/sdcard/Android/data/com.cooliris.media folder was consuming about 500 Megabytes(!). Apparently this folder contains the cache for Gallery3D, an app that I never use, and thumbnail images and indexes for Gallery.
Shortly after startup, either Gallery or Gallery3D appends indexes in the folder until the drive is nearly full. The phone slows to a crawl while this indexing runs in the background. I haven’t found a way to stop this behavior on my unrooted Android Gingerbread phone, so periodically I must liberate storage space.
I use Task Manager’s Storage option to check available storage space. If there’s almost no storage space available, I use ES File Explorer to delete the /mnt/sdcard/Android/data/com.cooliris.media folder. Don’t worry, the folder will soon be recreated.
What’s in a name?
Note that Samsung names its RAM drive device sdcard. It’s not actually an sdcard — it’s just a RAM drive. In my phone, the actual sdcard device is named external_sd. It’s confusing, but we must live with it.
The CTIA (Cellular Telecommunications Industry Association) announced in November that it had integrated its stolen cellphone database with similar international databases. A recent Verge article describes the importance of the overseas stolen cellphone market and the controversy that surrounds a built-in “kill switch” for smartphones.
The CTIA insists that its new improved cellphone blacklist will make “kill switches” unnecessary. We’ll see what happens to the market value of stolen phones.
The FCC has published the Android app’s open source code on its Github site. They’ve promised an iPhone version. It’s being developed by Samknows.com.
According to the app’s FAQ, “the application will run continuously in the background, periodically performing measurements.” I’m not enthused about having this app running continuously. I’ll probably uninstall it after each measurement run.
A feature of this app that I like is that it collects and reports “cell tower ID” and “cell tower location code” — data that may help my quest to pinpoint the physical location of T-Mobile’s nearest cell site. It also reports received signal strength in dBm.
The speed test data are collected from your mobile device and aggregated by the FCC. Let’s hope that they use the data to hold the carriers’ feet to the fire.
One reported problem is that the app, when testing over a WiFi connection, thinks that it’s connected via LTE. Also, it may have contributed to problems I had with other apps today.
If you examine the screenshot, you’ll see that although T-Mobile claims that the wireless connection (which was HSDPA when I snapped the screenshot) is “4G”, the download speed is a wimpy 1 Megabit per second. This disproves T-Mobile’s claim that HSDPA+ is “4G”. (The ITU specifies that 4G system mobile phones have a minimum peak download speed of 100 Mbps.) Maybe the FCC or FTC will do their jobs and slap T-Mobile for false advertising.
Adobe Flash continues to be a security nightmare. Adobe stopped supporting Flash on Android devices earlier this year, which uninstalled Flash from all Android devices. Eventually H.264 and HTML 5 will replace Flash. In the meantime, if you absolutely must have Flash on your Android device, here’s how: http://forums.adobe.com/thread/1061194. Caveat Lector.
T-Mobile’s GSM signal inside my house is marginal. My Android phone indicates field strengths from about -100 dBm to -113 dBm. (I *think* that GSM needs a minimum field strength of about -109 dBm.) I have a vague idea where T-Mobile’s nearest cell site is located, but I’m having difficulty pinpointing it.
I’ve found conflicting information from these sources:
Last week I stopped at the nearby T-Mobile store. To my surprise, none of their salespeople knew where the nearest T-Mobile cell site is located . . . nor were they interested. One guy has worked there since 1998, and never thought to learn the nearest cell site location. I’m amazed.
I spoke with a T-Mobile tech support person on the phone, who volunteered an approximate cell site location within a mile of my house. I walked in that residential neighborhood, and my phone indicated a signal strength of about -71 dBm — which would indicate that I was getting warm — but I was unable to visually identify a cellular antenna. There’s no tower, but there is a church nearby, and I’ve read that T-Mobile likes to place cell sites within church steeples. My guess is that this cell site is just a repeater, with no fiber backhaul.
If that’s the nearest cell site to my house, the signal’s path loss to my house is about 30 to 40 dB. That seems reasonable, as I *think* that T-Mobile operates in the 1700 and 1900 MHz bands and there are lots of mature trees in the path to my house.
Can you recommend a method of determining exactly where the nearest T-Mobile cell site to my house is located? Please?
I’ve had my Samsung SGH-T679 Insight II phone for about 13 months. It’s small, as is its battery. Battery runtime has never been great, but recently it’s been terrible. Last week, the phone turned itself off several times, and it refused to recharge today.
Jenson at the T-Mobile store tested my charger and pronounced it healthy. Kristen at the Batteries Plus store took one look at the battery, whose sides were slightly bulging, and pronounced it dead. She told me that a quick test is to place the battery on its flat side on a tabletop and spin it. If it spins easily, it’s bulging. Bulging sides = Dead battery.
I confess that I’ve left my phone on the charger for hours overnight, long after the battery was fully charged. I’ve also recharged it whenever it fell below 80 percent charge. Kristen explained that although the phone is supposed to have current limiting circuitry, it isn’t perfect. It’s much better to unplug the charger once the battery is fully charged, and to allow the battery to discharge to 20 percent or so before recharging it. I’ll follow her recommendations with my new battery.
The Power Matters Alliance (PMA) is a group of companies and government and academic bodies that wish to promote the concept of wireless power delivery to mobile devices. The smartphone is a 21st century invention, but the dream of wireless power transmission is at least a century old. My articles Wireless hype existed a hundred years ago, also and Wardenclyffe site to be acquired for proposed Tesla museum touched on this ancient dream. Tesla and Marconi dreamed of long-distance wireless power transmission. The PMA’s goals are more modest: they want you to place your phone on a hot-plate at Starbuck’s, where it will receive power through the miracle of inductive coupling. (Discovered by Michael Faraday and Joseph Henry c 1831, electromagnetic induction is the principle behind transformers and motors.)
As part of the IEEE Standards Association (IEEE-SA) Industry Connections program, the PMA is fleshing out a suite of standards that provide advanced wireless power – called ‘Power 2.0’
It sounds good, but there’s one pesky law of physics that interferes: The efficiency of inductive coupling is inversely proportional to the distance between the two coils.
Meanwhile, in the world of wired battery chargers . . .
In 2009, all GSM phone manufacturers except Apple agreed on a standard low-voltage DC charger-to-phone interface specification (GSM phones will have a standard battery charger), which was a big step forward.
The PMA has lofty goals:
It is estimated that by 2020 wireless charging could offset the equivalent of 289.4 million metric tons of CO2 and the equivalent of 482 100MW power plants. These savings could amount to a cancellation of the entire embedded energy usage of external power supplies by over 118%, thereby saving the unnecessary disposal of an estimated 4.5 billion transformers and associated toxic components into landfills.
It’s going to be tough to achieve good efficiency. I wish them luck.