My Arduino Babies

Preamble

How did I get into Arduino? That is a good question, and one whose answer will entail the discovery of Stack Exchange, Super User, just before Xmas 2014. I think I was just looking for an answer to a Wi-Fi issue that I was having with a Mac. That then led on to me exploring the SE network, and finding SE Raspberry Pi, with with I was already familiar, having heard about it in the British press (i.e. BBC News). Then there was a question asking something along the lines of “What should I get – an Arduino or a Pi?” I had never heard of Arduino and so did a bit of googling, at bit of researching, and then a lot more googling and researching, and realised that this was something that I wanted to get into.

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XBee expensive expenses

Preamble

I got hold of the excellent ebook, Building Wireless Sensor Networks – A Practical Guide to the ZigBee Mesh Networking Protocol, by Robert Faludi, published by O’Reilly. download it here or here. (Useful links: errata and; code).

Building Wireless Sensor Networks Cover
Building Wireless Sensor Networks Cover

I read a good part of it on Valentine’s day 2015 in Viva8, a kicking bar in Chatuchak market (the [in]famous big one in BKK, where you can buy snakes, dog meat, dinosaurs and old sets of false teeth).

I was hooked, they looked great, and the book was full of interesting projects. I soon figured out what was what, and what was required, or rather what I required.

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Choosing which Multimeter to buy

Preamble

I was living in Bangkok, and had resurrected my past interest in electronics, most notably through using Arduinos.  After playing about for a few weeks I realised that I sorely needed a digital multimeter (DMM). I already own one, from my days at University, 27 years ago, a M-776 Precision Gold Autorange Digital Multimeter (with transistor tester and display hold) from Maplin. Cost me £20 at the time, which seemed like a lot of money back then (For a pound you could do the week’s shopping, have a night out on the town, entertain some ladies and still have enough money to get the bus home – not any more, eh?), although I seem to remember it being a top of the mid-range model, so worth it.

Maplin Precision GOLD M-776 DMM
Maplin Precision GOLD M-776 DMM

I have still got the box it came in!

The Box that the Maplin M-776 DMM came in
The Box that the Maplin M-776 DMM came in

Anyway, I digress… so the M-776 was no good to me back in the UK, when I’m in BKK, so I thought that I might as well splash out and get a new one, for two reasons:

  • It is always handy to have two, so that you can simultaneously measure current and voltage, and;
  • The newer models weere bound to have better features than the M-776

Now, which one to buy?

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My first oscilloscope

Preamble

I’ve been looking at http://www.bitscope.com/pi/blog/ for some time now, it was one of the reasons that goaded me into buying a Pi 2 in the first place. It’s a scope, logic analyser and signal generator in one. Not something I’ve determined I even need, so for now I’m holding off, plus a little on the pricey side, £100, and of limited bandwidth (10 MHz).
Ah ha! That is the blasted link that caused all this in the first place. However, it is no good for me, a pathetically narrow bandwidth. As I’ve said, it’s about 10 MHz. I was using 20 MHz ‘scopes in Tech College and University, 30 odd years ago, and at the time I had always hankered after a 50 MHz oscilloscope. So 100 MHz would be exceeding previous aspirations. Ah well, I’ll probably never use it anyway. In Thailand, I bought a 100 quid multimeter that does everything, a UNI-T UT-71D, even heats up Baked Beans for you… yet I’ve only ever done continuity tests with it! A total waste of money, when a $10 DMM would have sufficed.
So anyway, I ended up buying a rudy oscilloscope on eBay this morning, half asleep, for 60 quid!!! I didn’t want it really, but had to go to Wokingham to pick it up. However, I also ended up seeing an old friend, who I hadn’t seen for a long while, so not a totally wasted trip.
“What do I need a silly scope for?”, I hear you say… well, I’ve got heavily into Arduinos. To date, I have 3 x Nanos, 2 x Unos, a Mega, a 3v3 Mini pro and a 3v3 Micro pro (these two all linked to the Pi and Motorola Lapdock), and a Leonardo. I’ve done some stuff, written a library for a dual seven segment display and a graphic equaliser display. Totally pointless waste of two months obsession. Now I am building a spectrum analyser. I found a great oscilloscope actually this morning, but only good for up to 300Hz. I got into the Arduinos via Stack Exchange (SE). Basically, by Xmas I was so bored of Thailand and the girlfriend and drinking excessively that I decided to do something productive and educational, instead of picking fights with the local Yakuza. So, I started answering questions on SE Super User. Then I saw SE Raspberry Pi so joined that, then heard about Arduino, looked into it, opened eBay and went wild. I literally had five packages a day for two months arriving cheap from China. So, now I have a suitcase full of multimeters, Arduinos, shields and modules but no clothes.

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