As you are no doubt aware, the editor of MCU Designline -- the illustrious Max Maxfield -- is currently on a quest to learn the Arduino. In one of his recent blogs -- It's Crunch Time for Me to Learn the Arduino -- Max said the following:
My most recent fling was playing with a PICAXE controller board based on a Microchip PIC; I programmed it using a form of BASIC. The PICAXE was a lot of fun, but it's too low-level for what I need.
This gave me some cause for concern, as I had coincidentally just ordered a small PICAXE kit as part of a special offer by one of my suppliers. I raised this as a comment in Max's column, wondering if I'd done the right thing. In response, Max went to some lengths to justify his own interest in the Arduino, but he also said: "...for just messing around with your own projects, I think you will love the PICAXE."
Before we proceed further, let me give you a little background. I did a bit of microprocessor programming in the "good old days" -- the 80s and 90s -- mostly on the 8080 and the Z80. My life then shifted more into telecom, where I work to this day. But modern telecom has grown increasingly divorced from the electronics that supports it, and I have felt a strong desire to get back to the electronics side of things. My recent programming has been mainly on things like PABXs and Procomm at work, so I took the bull by the horns and ordered the PICAXE kit.
I have done a lot with BASIC in the past, including the old Sinclair ZX81 and Spectrum, and I also programmed a terminal emulator in Qbasic. The end result is that I got pretty good at BASIC, so I thought the PICAXE would be a good starting point for my foray into microcontrollers. I'd also like to learn C at some stage, but for the moment I wanted something I could get to grips with quickly for a few ideas I wish to "mess around with," as Max puts it.
On top of everything else, Max then asked me if I would write a couple of blogs on my experiences with the PICAXE system. Having Max nipping at your heels for blogs to post is a fine incentive to get going and do something, so I jumped at the chance.
The PICAXE world consists of various Microchip MCUs that have been pre-programmed with a bootstrap loader that enables very easy programming without an expensive programmer. These are coupled with a development environment that lets you write programs in a variation of the BASIC language. The available chips range from the 08M2, which has 8 pins and 6 I/O lines, to the 40X2, which has 40 pins and 33 I/0 lines.
Programming (on PICAXE's own boards) is performed through a 3.5 mm stereo type jack connector like those used on MP3 players. All the chips offer analog-to-digital converters (ADCs), pulse width modulation (PWM), I2C and serial connections, and touch interfaces, as well as standard digital I/O. The larger ones also offer SPI and a couple of other options. This is all pretty tasty to someone whose last hands-on experience was with systems that needed vast arrays of chips to achieve all the above, though I have kept a hands-off eye on microcontroller technology and pretty much knew what to expect.
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