Showing posts from April, 2017

Resistomatic - an Arduino-based autoranging ohm-meter

Sorting resistors is a pain If you've been having fun with electronics for a while you've probably got a box with bits in . I've been playing with electronics for six decades and I have lots of boxes, many of them containing random collections of resistors. Resistors are cheap, but I hate waste, so from time to time I decide to empty some of the boxes and put the resistors away in their proper homes. It ought to be easy, but it's a pain. I was never good at reading colour codes, and the problem has got worse with age. What I want is a simple, quick autoranging ohm-meter that I can use to measure resistor values. So I'm making resistomatic . Resistomatic requirements Most of the resistors I use are 1% or 5% tolerance metal film resistors in the range 220 Ohms to 100K Ohms. Almost all the values  are in the E12 range. (E12 values are multiples of 1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2). I'll be happy if resistomatic can achi

Program the Proto-Pic EDGE using O O MicroPython - part 1

Good programmers are Lazy. According to Larry Wall (a very famous programmer) laziness is a virtue. Lazy programmers come up with labour-saving solutions. If you’d like to save time for yourself and others by writing MicroPython code that’s easy to re-use, read on. The article assumes that you are already familiar with the concepts of Object, Class and Composition, and that you know how to write a class definition in Python. If you’re not familiar with Object-Orientation (O O) in Python  you may find the code hard to follow. I’ve given a very brief introduction to O O later in this article. There are several ways to learn about Python O O. There’s an ‘official’ tutorial here , but I’m not sure a beginner would find it easy to follow. There’s a whole book on the subject from Packt, and it looks good. It represents quite an investment in time and money, but I think it’s worthwhile if you are serious about improving your Python O O skills. I will probably get round to