Justblairs Audio and Electronic's Pages

I have been busying myself recently with some experiments into programming the Arduino prototyping platform. 

I have already created some hardware, a Maxim DS1307 Real Time Clock shield and a Serially Interfaced, 8 digit 7 Segment Display based on a MAX7221 IC.  So far I have created test routines to test my hardware but I wanted to really get my teeth into creating some more practical code. 

And here it is, A more or less functioning LED clock. 

I have included a download of the sketch (Arduino speak for program) that I wrote so that Arduino owners can examine and play with my code, There is a cheesy video blog at the end of the article as well if you want to see the clock in action…

In a lot of your electronics projects you may need a display to provide information to your users.  These days the project builder has a plethora of options to consider when deciding on a display.  The needs of the project will dictate to some degree what technologies suit. 

The first thing to consider is what types of data you wish to display, do you wish graphical, text or will a numeric display suffice?  Next we must think about the look of the display and the readability.   Different technologies (i.e. OLED, LED, LCD, OMED) all have their own visual signatures and limits and benefits.

This project uses 7-Segment common cathode numeric LED (Light Emitting Diode) displays.  The 7 segment display has been around for years and gives projects a cool retro look.  Readability is very good from this technology and displays are available in a multitude of sizes.  So for projects that need to be read at a distance this is a very scale-able option.  Thanks to the Maxim MAX7221 IC (Integrated Circuit) it is also very easy to control these LED displays using a microcontroller such as the AVR processor within an Arduino.

Got an early birthday present today, A commodore LED wrist watch, Circa 1975.

 I don't know why I have wanted one of these for so long, but I am chuffed to bits with it.

My partner Janice bought it for me for the special day, though I have received it a few days early.  She purchased it from flea-bay, and I must say that the seller is to be recommended.  Phil was most helpful when her pay-pal account mysteriously decided to limit payment options to e-cheque for the purchase (happened to me a while back when I replaced a broken credit card).  If you by some miracle stumble upon this blog, Thank you from me.  You went beyond the call of duty to ensure I got my birthday present on time! 

Not only that, the watches he has are New Old Stock, and the emphasis is on New here.  The watch was still in its original box, with plastic cover on the lens.  Phil even had fitted a new battery, and set the date and time.  He supplied extra links for the watch and a replacement plastic face. 

It came with a copy of the instructions which boast.

• 5 functions (hour, minute, month, day and.... wait for it..... seconds)
• Stainless steel bracelet
• Stainless steel back
• Base metal (rare and precious base metal no doubt) case
• Magnifying lens
• Only looses 15s per month

It might not be everyone's bag, but I am in Geek Heaven!  Thanks Janice

Anyone out there fancies a vintage 1975 timepiece, Visit The 70's LED Watch Shop for a splendid retro timepiece.  (This sounds like an ad, promise that I have no affiliation other than customer with this e-bay store)

My birthday is on Tuesday, I have heard a rumour that my other presents may be just as geeky.  Watch this space!