2014. január 28., kedd

ARM Course 1. - First Impressions

So, I started the course. Within not a full week I finished 5 modules. Until this moment I lost only a half point (just because I was not careful enough).
Unfortunately until now I feel this material is not deep enough to me, but I'm not a C programmer ace. I hope that the later material will be harder, because under a name "Lab" writing a multiplication of two unsigned integer within a conditional block containing and relation of four basic expressions took me less that two minutes and it was producing a 100% in the grading on the first run.
If it goes this way, I'll finish the course in no time, but the learning value is doubtful to me. :-(

2014. január 26., vasárnap

UV Lightbox 13. - Controller

As I planed finished the controller for the lightbox.
The schematic:

The PCB design:

The etched, drilled, tinned PCB:

And the finished board:

I'm almost at the and of this project. What's left:

  • Some woodwork. I need some hole into the base plate, to fix the controller. Create the wooden frame (cut, drill, glue, polish, paint) and the foldable top plate.
  • Some metalwork. I need some aluminum spacer what I have to cut, drill, screw.
  • Repair the contact faults of the display.
  • Cabling, assembling.
  • Finishing the software
  • Documentation, article

2014. január 24., péntek

ARM Books

In connection with the course  I've ordered the books wrote by the teacher on this topic.
These books also arrived on Wednesday:

In the mean time the optional Nokia 5110 display also arrived so the package is complette (I don't count the resistors, leds, etc. because I have them anyway at home)

It has begun

On Wednesday evening the ARM embedded course has begun:

Yesterday evening I completed the first two modules with 100% result.
If somebody interested the first part of the videos are available here:
It seems to be that the rest of the videos will not be accessible through this channel. So lets register, it's free! 

2014. január 23., csütörtök

Frequency counter V2 11. - PCB Design/Manufacturing

Sience a few days the schematics, the PCB design and the "enclosure" design finished.
Here thay are:

I've ordered already but likely I'll run into the Chinese festival season. So it will be shipped after 4th february.
I also ordered the acrylic sheets for the "enclosure", but not from China. There are things what cheaper here in Hungary then there. :-)

2014. január 15., szerda

Frequency Counter V2 10. - Error correction

I started to work on the frequency counter again. Back in December, I found a small hardware design flaw. Specifically, I 'd forgotten that the open collector switch the ULN2803 Darlington array is logically negated. To be precise the problem is not with the ULN2803. It just do it's job, driving the "high current" cathodes of the display. The problem is that the ULN2803 is driven by a Johnson decade counter ( 4017 ). I use the ninth output for reading the jumpers. And here, I did not take into account that this output is not negated. As a result, I soldered the eight diodes with reverse polarity.I handled the problem from the software but didn't wanted to keep that way.First, put together the fix on a breadboard (diodes and a dip switch) and tied to my prototype.After that, I changed the code, which has been working for the first attempt (you may consider it as a miracle).

Finally, with some soldering rework changed the polarity of the diodes.
This prototype (at least the hardware) is complete . Now comes some work on the schematic and the final PCB design.

2014. január 13., hétfő

Office 365 - Microsoft way of handling things

On Friday some of our colleagues from the London office reported that the Outlook is unable to connect to the Office 365.
I checked if something happens with the Office 365 service itself. The Outlook access was definitely not working from the morning. Here is the service report:

I can translate the above report to a simple conversation between the support and the client (note: the conversation not actually happened):

Client: - Not working
Support: - We checked, working
Client: - No, it's not working
Support: - As I told before - IT IS WORKING
Client: - No, no, no. Not working. I'm unable to use it.
Support: - I tell you. Loudly and slowly - I T   I S   W O R K I N G !!!
Client: - I don't believe. I CAN'T WORK !!!
Support: Ooops. It doesn't work. We fix it.

2014. január 9., csütörtök

UV Lightbox 12. - Software

It been a long time since I haven't written anything. This period does not passed without trace. With quite some effort the lightbox software finished.The current status :
  • The counter and the buttons are working
  • The load switching works
  • The piezo buzzer works 
  • The functionality can be configured via USB
  • The settings can be saved to flash memory
This status can count as final, however I have a couple of things what I'm planing to imrove:
  • Improve memory organization (I'm running out of RAM and didn't like it)
  • The serial input buffer code cleanup (currently only fit one byte into. Means the Backspace does not work, it would be nice to convert the input handling completely to interrupt based, because this half interrupt, half status polling not seem to be stable)
  • Expand the configuration capability with the remaining settings such the length of beeps and tones .
This project will be a base of other gadgets therefore I need additional functionality:
  • BSL (bootstrap loader) - because it has serial port / USB anyway, why not to use for firmware upgrade
  • Clock function. It can work as a clock when the counter not running
  • Trigger based control capability
  • Energy optimization for battery based functionality