Thursday, February 7, 2013

Blackberry Z10

Update I switched to using the Q10 because of its excellent keyboard - however blackberry has dropped the ball on this device - the screen's brightness is half that of the Z10 and darker than even the 9800.  I didn't think to check the brightness before I purchased a $900 replacement for my Z10.
I have been a loyal user of RIM/Blackberry devices since the 957 around 2000.  The Z10 is around my 8th blackberry and the first that has left my belt clip.  Previous versions of the blackberry OS up until 6  had performance and crashing problems that usually only occurred under load (like opening more than 5 tabs in the browser.

I have however found a bug in the new QNX blackberry 10 OS that is quick to reproduce.
Open calendar, switch to month view, add an event and try to change the time in the date roller - the application will terminate and send you back to the home screen.  The workaround is to accept the current time and then reenter the item and modify the date.

I am also an owner of an iPhone 4s, an Android 2.2, and Android 4.2 tablet and a playbook, I like the Blackberry Z10 better than all of them.

/michael

Thursday, August 4, 2011

Electronics Distributors and Designers

Here is the list of most of my suppiers, lately I stick with Future.
                Note however that there may be a 40-200% price difference for some things
                Like 74hc283 4-bit adders are 2500 minimum order at digikey but future allowed me to order 25
                Future once had the XMOS processor boards at $65 but they were $100 from digikey
                Digikey lists parallax boards at $50 but they were $25 at parallax.
                Sparkfun seems to have consistent prices.
                               

To lay out breadboards you can experiment with

Future Electronics – montreal – future is the best with no import duties – this is where I got all my raspberry pis and most of my 74hc chips


Active Components – good for breadboards, wiring and power supplies/meters but I don’t buy components there anymore
Active Tech, 1465 Merivale Rd, Ottawa, ON K2E 5N9, Canada


All the following may have shipping and/or import duties from 20-40% + exchange
I have ordered from all of them over the years

Sparkfun NY – all components


EvilMadScience CA – mostly for LED projects and DIY projects –husband and life team
You can order their cat


Parallax CA – parts around robots and their 8-core microcontroller
I have most of their custom controllers and a lot of their propeller boards

XMOS
Makers of the replacement of the transputer board – 32 thread – 4 core microcontrollers

digikey – I might have ordered once from them but Future above covers them off

MountainKingTech – I ordered enclosures and a 100’s lot of angle brackets and bolts for connecting boards together





OctoProp Thread (using Pems chain boot method 1 sec/chip)
http://forums.parallax.com/showthread.php?115925-OctoProp-Demo&p=839672&viewfull=1#post839672
https://sites.google.com/site/parallaxinretailstores/home/altimeter-module-ms5607

Saturday, November 6, 2010

Combinatorial Parallel Logic Unit - Minimal custom Mesh Processor

This device consists of very simple logic processors (a combination 74251 encoder / 74374 D flip-flop memory) in parallel in pure TTL logic connected in a linear array. The hardcoded algorithm is the Wolfram encoded 2-state cellular automaton.




Wednesday, November 3, 2010

LED powered by Silicon Solar Cell in overcast sky

I was amazed that a small solar cell assembly sold by Sparkfun.com was able to lightup a standard red 1.8v LED under only an overcast sky.
Also noteable was the fact that i did not need a series resistor as the inherent resistance of usually 8 ohms combined with the post resistance allowed 5-15 mA to flow no problem.
This was just a proof of concept and not really usefull in itself, but i should be able to power ano embedded controller like the propeller or xmos G4 using only a panel or two.

Tuesday, November 2, 2010

How to use Clamp Meters : Agilent and Sperry

If you are like me, you need to measure electrical current (Amperes/Amps/A) so you can figure out the power used by your electronic circuits (Watts/W - or Volt-Amps/VA) - not to mention the power used by your toaster (a surprising 1 KW).

You need a Clamp Meter! I currently use the Agilent U1211A.



When I first got a Clamp Meter from Fluke Inc., I could not get the thing to work, I put it around every electrical wire I could find - no effect. Only later did I realize/remember that the two AC lines were cancelling each other out - I needed a line splitter.



Therefore, to measure AC and indirectly DC current you plug in the line splitter into your 120V ac outlet and clamp the Clamp Meter around one of the 1x or 10x split lines. Your clamp meter will experience a magnetic field proportional to the current and display the Amps for the 120v line.

You take the Amp reading (say 5.56A) and multiply by the Voltage (usually 120V) and get your Wattage (W = AV) or 657W. Since Physics 102 I remember this as WAV or PIE (as in power = current * electromotive force).

In the photos, I am running 4 PC's, 2 monitors, and XMOS processor and a Parallax Propeller based obrienlabs LED display board.





The amp reading comes in as 5.5A on the Agilent clamp meter and 3.8A on the Sperry clamp meter - why different readings? True RMS - more about this later.



The Agilent U1211A True RMS Clamp Meter is excellent and comes with a calibration certificate - therefore I trust it's reading.

The Agilent meter (formerly part of Hewlett Packard - HP) can measure up to 1MW, it is a little overkill but worth the price. One observation is the fact that for low wattages like 100W it takes about 5-15 sec to stabilize the Amp reading due to the small magnetic field on the clamp.