Saturday, 25 February 2012

The Mad Mad World of Microcontrollers

It's been a while since my last blog, and that has been bugging me to the point where I feel I have to "tick the box" and "blog SOMETHING", so here it is.

The last entry was made shortly after I'd "discovered" the Arduino system, and this discovery has let me spiralling off into all sorts of strange directions, all associated with microcontrollers, one way or another.

In the meantime I've bought what I think is a rather good book called "The Quintessential PIC Microcontroller" by Sid Katzen which deals with the subject manner in a way which resonates with the way I approach things.   Recommending books is a dangerous business, rather like recommending restaurants or wines or other things which are extremely subjective in nature, so all I will say is that I think it's rather good and leave it at that.

I've also acquired a few bits and bobs associated with Atmel AVR microcontrollers (an Atmel AVR is at the heart of the Arduino), namely a "TinyUSB" programmer, a few low-end microcontrollers, an LCD panel, and I've just downloaded the AVR Studio IDE package from the Atmel web site.

Buying expensive text books apart (I only have a couple of microcontroller books, honestly!) the best way to "learn microcontroller" is by doing stuff, so that has now become the prime objective.

I should relate the story where my eyes were opened about the desirability of using microcontrollers.  This was when I was participating in a Radio Club project to scratchbuild a 70MHz transceiver (The Eden 9 Project) and had got to the point where working IF strips were emerging from our group of constructors.

The IF strip had been deliberately designed without an AGC system, but with the facility to add AGC later, and a prototype audio-derived AGC system was duly demonstrate.

Now some people are rather "sniffy" about audio-derived AGC - I may or may not have been one such sceptic, I couldn't possibly comment! - but this demonstration was remarkable!   Not only was the performance of the circuit so impressive, but the parts count (and cost) was so low!  

Of course, as I am sure you have worked out already, there was a PIC microcontroller at the heart of this little add-on board, and when one stops to consider how the "all analogue" alternative might have been designed then it doesn't take long to realise that the alternative would be more complex, costly and less flexible.   With a microcontroller prototype, just changing a few numbers inside the embedded program is the way performance is tweaked.  To cap it all the PIC at the heart of this unit retails at around a pound at time. Good value, or what?

All I need now is the time, willpower and inspiration to get down and learn the ropes properly.