Windows 8.1 - mired "freedom"

I was at a conference organized by Freescale. I wrote about it earlier here.
What they did not write, it seemed only a small inconvenience with the Freedom board what they give away. I could not breathe into life the OpenSDA debug firmware. Finaly I loaded on my neighbor's the machine. I thought, I screwed up something for sure.
Since then, it turned out that it was not my mistake, but also ran into this issue:
http://mcuoneclipse.com/2013/10/12/frdm-board-bootloader-fails-with-windows-8-1-preview/
So the Win8.1 and OpenSDA not love each other. :-(
For now there is no solution, so the upgrade of my developer machine is a question.

Work

As of today I'm working at a new place.
Here:

The things what the R&D team is doing in the company is a little bit futuristic to me but my duty is only the support of the infrastructure: Windows, Exchange, SQL, CRM, some Linux, etc.

Installing Ubuntu on BeagleBone Black 2.

Last time here I wrote about my adventure with the BBB and Ubuntu.
Now I have a task to create a kiosk like something from the BBB. When I tried to install the desktop environment on the BBB realized, that it won't fit into the 2GB integrated MMC. To go further - If I install the ubuntu image to an 8 gig SD it still create a 2 gig ext4 filesystem. When I tried to expand it I get some strange error. Finally found the solution:

1. Put the SD card into an USB reader and connect it to the BBB
2. Boot the system from the MMC
3. Install the ubuntu image to the SD card as mentioned in the previous article
4. delete the ext4 partition (namely: /dev/sda2) with the cfdisk and recreate it to fill the whole free space on the SD card (in my case it will be a partition little bit smaller than 8GB)
5. Repair the partition:  e2fsck -f /dev/sda2
6. Expand the partition: resize2fs /dev/sda2
7. Shutdown the system
8. When it finished you can put the SD card into the holder on the BBB, boot to ubuntu and do whatever you want

After that I installed the xubuntu-desktop environment but realized that it extremely slow and even hangs after a few mouse clicks.
Today in the morning I reinstalled the whole thing with lubuntu. I had no time to wait the completion of the process. I'll see afternoon if it works correctly or not.

Sample ordering - Next Round

As a month ago I ordered some engineering samples. This time not from TI but from Maxim Integrated. Today arrived kind letter asking me to fill and send back a Statement of Assurance letter for the US Export Control.
This time I'm not as lazy as last time. I just filled and sent back the form almost instantly.
We will see what happening.

Double Multiplex 3.

The PCB fully finished now and I created a test code for MSP430 (it is still bumpy a little bit and ~600Byte). It working quite well but the brightness is not to high. Actually in theory it has 12mA current per segment what I don't want to increase for testing (In theory I can increase it ot 20-25mA. The LEDs are capable to handle 100mA with 1/10 fill factor but the MCU don't). So I've 33ohms current limiting resistors what finally can be decreased to 22ohms: (3V - 2,2V) / (2 * 22) = 18mA.
 

Double Multiplex 2.

The PCB for the testing has been finished. Unfortunately just the empty board, because the weekend InetPub party left no more time to me.

I'm calculating now how big resistors are needed to get enough brightness even though that we have 1/64 time slot for driving one LED.

Double multiplex

My head is full with planed new electronic projects. Most of these contain some - especially LED based - display. Even with my Frequency Counter project caused some headache driving the display. If I want to use the minimum amount of external components than an 8 digit 7-Segment multiplexed display requires 16 I/O pins, what is problematic with a small pin count MCU. In addition, it requires external components because an MCU is not able to supply the current required by a whole digit. The lack of enough I/O pins driven me to use an additional IC (74HC238), 8 transistor and 16 resistance  for the display (the transistors and half of the resistors could be replaced by a darlington array, while we using common cathode displays. For common anode this is not an option because PNP array or common collector NPN does not exists). As I was searching new ideas for one of my new project on the net, accidentally came across an EDN article. This article is about the "double multiplexing". The point is that at any given moment we drive only single LED from the entire LED matrix. This reduces current consumption of the circuit, the number of required external components, and the amount of required I/O pins. The display mentioned above can be driven by nine pieces of resistance and 9 I/O pins. The question we should answer, if we can generate enough current for brightness and fast enough code to avoid flickering.
We'll see.I definitely want to try the stuff, so I designed a test PCB (I hate to put this amount of jumper wire into the breadboard).

 

I'll try to put it together during the weekend and writing the test code is the next.