Friday, December 27, 2013

Successfully interfaced TI Sensortag to exercise bicycle.

I successfully interfaced a TI Sensortag to an exercise bicycle. I measure the heat generated by the friction brake with the passive IR themometer and the the revolutions by wiring the bicycle's magnetic sensor to one of the button switches on the Sensortag. I successfully received the data using Bluetooth 4.0 communicating with a Nexus 7 (2013). Wiring the switch required the skills of a neuro-surgeon.  Texas instruments should add a solder pad to the back side of the switches to aid in development. 

My RFduino Development Kit Arrived

My RFduino Development Kit arrived after many delays. I will testing it in the next few days.

Friday, December 13, 2013

What to do prior to wrapping up that tablet computer for a holiday gift

If you are going to give tablet computer for the holidays make sure you verify that it works properly before you wrap it.
Here is a test that I would do: go through the setup with the account of the person you are giving it to including connecting to your WiFi network. 
Let it charge.  
Restart the computer and see that it boots properly. 
Put it to sleep by a short click on the power button. 
Let it sit without external power for 24 hours. 
Give it a quick click on the power button. It should come right back to a lock screen. 
A swipe on the lock screen should return you to where you left the computer
If not it has crashed and needs to reboot.  
This happens occasionally, but if it is happening almost daily, return it for a new one. 
If it fails the first test, try once more but with shorter test time, 
if it fails again return it otherwise wrap it. 
That way when it is unwrapped a quick click restores it to an instantly usable computer. 
If it failed at all during testing watch it closely and return it for new one before your return privileges expire.
The question of battery life comes into question. Sitting wrapped up under the tree the computer will automatically be checking email and beeping when the person whose account you set up gets an email. You might want wrap a dummy gift with a quick switch door in order to swap a fully charged and functional computer into the package at the last minute. I took a look at how the Nexus 7 consumes power and one guy says that it will lose 5% per day in the sleep mode. Personally, I would opt for dummy package with a quick swap door.  Nobody likes electronics with a dead battery.

Tuesday, December 10, 2013

What would you say would be a good inexpensive tablet to get?

There are a few things to consider. When they produce cheap tablets they leave out things.  Here are important questions.
1. What version of Android does it run?
Android 4.0 is too old.  Minimum should be 4.1, preferably 4.3 Stay away from the Amazon tablets (my opinion)
2. Does it have Google Play?
If it doesn't, it means the computer couldn't conform to Google's minimum standards.
3) What resolution is the screen?
High definition 720P is 1920 by 720.  the closer you get to that the better. Most cheap tablets don't even come close.
4) How many cores does it have?
Cores refers to the number of processors contained in its processor chip.
 Cheap ones are single core, better ones are "dual core" (two processors)  the best are "quad core" (4 processors) Minimum should be a "dual core" tablet.
5 What other things were left out to make this tablet cheaper?
No bluetooth .  No GPS.  Small battery. 

So those questions will allow you to compare tablets. The reason that I don't like Amazon tablets is that they produced a "fork" of Android in which they modified the operating system so that it is difficult to run anything other than what they want you to.  The Kindle book readers are supposed to be great but I recently worked on a Amazon tablet and I was frustrated by their Operating System. That means older versions of Google's software and then they update it when they feel like it. 

So based on that I bought George a a dual core 7" Nextbook. No bluetooth or GPS. The screen resolution was not great but it was better than the next cheapest one and it had Android 4.1 and Google Play.  Price $79 It was acceptable.

So $79 is $60 away from $139 which is the cost of a 2012 edition of a Nexus 7 running Android 4.4 with 720P HD display, Bluetooth 4.0, GPS and a quad core processor.

$79 is $150 away from 2013 Version of the Nexus 7 which is the best Android 7 inch tablet available. 

So there you have it:
Minimum: Dual core cheap tablet (watch the resolution of the screen) $79
Preferred: 2012 version of a Nexus 7 $139
Best: 2013 version of a Nexus 7 (not refurbished) $229

Make sure you check your return policy.  I had to get three tablets before I got one that worked properly. They had a lot of problems with their first production run.  You don't want get a lemon. I bought mine on Amazon and their return policy was great.  It was disappointing to get the first two lemons but they kept bringing me ones until I got a good one. I was literally handing the UPS driver the old one as he was delivering the new one the next day. (I had bought it with next day shipping)

I hope this helps. 
I will be posting it on DaveThe because your question is an important one.

Walmart has this for $109 online.   It's refurbished (used) but it is a good computer. One of my friends bought one for his son.  It equals the Nexus 7 2012 version and even surpasses it because it allows  additional storage space and HDMI out.

Hisense Refurbished Sero 7 Pro with WiFi 7" Touchscreen Tablet PC Featuring Android 4.2 (Jelly Bean) Operating System, Brown/Black
Model#: M470BSA
7" touchscreen
1.3GHz NVIDIA Tegra 3 Quad-Core processor
8GB of storage memory
Google Android 4.2 (Jelly Bean) OS
Webcams, WiFi and Bluetooth