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Tools and Techniques

A starter digital electronics lab (we do not call them spare rooms or offices.. for science!) need not be overly expensive; you should invest in a few basic tools, and a good soldering iron. ebay and kijiji and local ads are your friend. We almost feel guilty about ordering from China, but when you can get (dubious quality) parts for sometimes 10% the price ..

Tools

Basic tools you will want:

  • Solder station (get yourself a Hakko FX888 or equivalent - something you can depend on) - check Ada, Sparkfun, or ebay for deals; or a cheapo from Radio Shack if you must; you can get by on a cheapo $5 iron, but this is somethign you'll use every day hacking around on stuff so its worth spending a bit of money on. I know I know, $$, but still. Its not a lot of money, and its worth it. Shop around. Check ebay.
  • Variable power supply - you can live without by making purpose-built dedicated little supplies for each project, or buying a little $15 breadboard supply from Spark Fun, but getting a Elenco power supply kit is not overly expensive, a fun little assembly project, and will get you a decent 5V, and variable DC and AC outputs; its nice to have a 'plug in and go' power supply to save you buying voltage regulators on need, and nice to be able to have a couple different voltages on tap without voltage bridges. Fancier power supplies cost a couple or few hundred but have more safety features, more outputs, digital or needle displays..
    • You know, now that I'm good at making my own boards.. I put together a little tiny pcb that spits out 3.3V and 5V reliably; thats all I need. You can get cheapo little kits for $10-$15 to do this, too. I really like having a variable power supply to get those odd voltages, but you can live without it.
  • DMM - digital multimeter; get a decent one, with a decent brand; the knockoffs can actually be _dangerous_ to you! Make sure you've got a 'beeper' for resistance continuity checks; ideally get one with 'auto ranging' to save you having to set the 'range' every test; ideally get one with a backlight.. most modern ones should be doable. You do NOT need a 'bench multimeter' - they have less features, and cost a LOT more, than the handheld units .. simply because people do not buy them anymore.
    • But I really like the form factor of a bench MM, so I picked up a 20 year old one used, and works great ;)
  • Breadboard; you can find the cheapo single-board units at your local electronics shop, or buy them cheap on ebay; $5 a pop, say. You can find higher quality and much stiffer units (stiff is good, so wires don't just pop out or make contact issues.. last thing you need to debug is having 100 wires down, and one is loose!), so I'd suggest getting a 2 or 3 board unit; I've got a 3 board (3 standard breadboards stuck together into a bigger aggregate slab) that I do most of my prototyping on. You'll use it every day, like your soldering iron, to slap little test circuits together. (They're good up to abot 10MHz of signal change, which is pretty good; typically your cpu will be 16-20MHz, but even if its 200MHz.. thats _inside_ the cpu; the actual signalling coming out is usually much less. If I can drive VGA 25MHz pixelclocks on a breadboard, its a pretty solid little piece of experimenting technology. Get some.)
    • Even the little tiny half-single-board ones are handy; now that I'm good at making pcbs I often just go straight-to-pcb and no perfboard or breadboard; but you still need to have a little BB around to put jumpers over to, or to trial a part, etc. ie: The zik80 base pcb has some power pins available, and some various breakout pins like GPIOs; jumper over to a breadboard from a GPIO, add a resistor and LED, and voila.. easy way to toggle on and off some LEDs as outputs. Did the code work right? Turn on a LED! No need for serial logging….
    • I actually found a deal on normal cheapo breadboards, and bought 10 of them; I put them all together into one big aggregate mega-breadboard, for assembling enormous projects like the zikzak double buffered hardware upon. Use a cookie sheet as a foundation for such a crazy thing - it makes a good 'ground plane' if you ground the sheet, soaking up all the stray signal noise!
  • magnifier/lamp - a desk lamp with a flip lid revealing a magnifier, with a ring light around it; really handy for a lot of basic inspection of work, to make sure there are no bad solder joints, or whatever; you need good lighting on your workbench (which may be your computer desk or TV tray :) Also, cool.
  • assortment of pliers, sidecutters, wire strippers .. get some halfway decent of each; fine tip needlenose for picking up or placing stuff, sidecutters for taking the edges off solder joints or a million other thing, wire strippers…. duh.
    • honestly, you need a needlenose, a cutter, a really sharp little sidecutter
  • wire spools; you can get some nice packs online, like Sparkfun will sell you a little box with 5 or 6 different colour spools in it with the right gauge for breadboard; your local shop will likely have an assortment of wire colours in an assortment of gauges - most people prefer AWG22 or similar wire gauge for general day to day work. Wire is metal, and is expensive, sadly (and surprisingly!); get the single core stuff, to start with; the braided wire is good for certain things, and is way cheaper, but no good for digital electronics to start with.
    • Wire is fun to have around, and you always need some; at first I used a lot of it (a lot of perfboards and jumper making) but now I don't use so much, since I'm making PCBs; you could get by with just a big whack of pre-made jumpers, too. Really, you need those too, for your breadboards.
      • For jumpers, I keep a little parts box ful of various sizes and types; male-male for breadboard jumpering; male-female for hooking up some pins to a breadboard; female to female, for header to header jumpers; get all 3 variations, in medium size.
  • USB Microscope - moved from optional to required! These can be cheap to medium-cheap; get a decent one, with a stand; Andonstar is what I have, and cost me like $40 or something on ebay; its _Really_ handy, especially for surface mount work (tiny pins in high density); its great to plug it into your PC and see a big 20“ zoomed in view of your solder work, so you can make sure its a solid connection without bridges; when soldering a 64pin, 100pin, or 144pin or more piece.. you need that. Need.

Some nice to have tools:

  • Oscilliscope - You really should have one - something that can do 50MHz or more ideally - and with 2 or more inputs; I'd say this is a requirement but they get expensive fast. Still, you can find digital units cheapo on occasion, or a beat up old analog unit that is beautiful…. but may be out of calibration from being 30+ years old. The Rigol DS1052E is popular since many of them are moddable from listed 50MHz to 100MHz for free, and is generally a pretty good workhorse.
  • Logic analyser - an o-scope is amazing, and get that before a LA; an o-scope measures voltage over time (and can be made to do amperage too, using an amp-probe); a logic analyser is similar, but only measures the digital result of that voltage .. a 0 or 1; for example if a 5V line is showing say 2.4V or higher, thats a '1'; less is 0; an o-scope shows the actual voltage, but an LA shows the 0 or 1. The difference is most LAs can take many signals (such as 8 or 10, or more) at once, where an o-scope can usualyl only do 1 or 2 (or more for huge $$); many LAs can dump the data to a computer for analysis as well – interpret the 0 and 1s of a given set of lines as serial or i2c, and see what the messages actually are. So while an o-scope will help you create and debug a protocol system, it is not so good at decoding one; but a logic analyser will decode the voltage stream as data and even show you whats in it. Awesome. But totally optional
  • Hot air rework station

IC and Passives Inventory

Theres some basic parts you'll want to acquire .. things you will often need, and want in your parts box. Also, get a parts box or wall hanging kit of drawers.

Rule #1: don't throw things out at home anymore - not without taking them apart first. With a soldering iron, or maybe a heat gun (a heavy duty hairdrier from an electronics shop), or other tools, you can pull or desolder or melt pieces of damned near anything; with a heatgun and pliers, you can pretty much melt 50% of the parts and connectors off a PC motherboard, and I bet you've been through a few of those over the years. Heck, you can drop into a garage sale or computer shop and pick up old video cards or old mobo's dirt cheap, and melt off all kinds of goodies. But more to point, since thats a little hard core.. you break your exercise machine? I bet theres some sensors, or an LCD display panel, or some buttons, or some voltage regulators, something in there, that you can clip off, or desoler with a few minutes work.. valuable parts, to save you money, and its fun to do; you'll learn some physical design and get handy while you're at it. I'm a software guy by trade, so getting into the real world, pulling everything apart, is great. Also, it teaches the kids some valuable lessons – things are not disposable.. they're repairable!

I tend to suggest getting a few of each thing, too; you don't pick one up line driver/buffer chip, you bu a 2-pack, or get 3-4; you may kill one, but more than likely you'll need 2 in a project; what if you kill one, and still need 2? have 3 on tap :P Most of the basic parts are cheap, and you can get them online for pennies. I mean, a lot of basic ICs will run 20c, or can be gotten as free samples. Skip lunch out one day, and buy a pack of 40 ICs instead. Good times.

  • Microcontrollers of your choice
    • Atmel Atmega's are popular 8bit devices, especially with the Arduino movement using them
    • Microchip PICs have always been very popular, with a wide assortment of features
    • ST Micro STM8 are in the same arena as the Atmel and Microchip offerings; the STM32 line is a very high end micro that rather leaves the Atmel and Microchips in the dust; 32bit chips are generally much more involved to set up and use, while the atmega and PICs are a piece of cake (on Linux too!)
  • Voltage regulators - nab yourself some 7805s for example, so you can feed in a 9V power brick and adapt it to a steady 5V you can feed your mcus
  • Crystals - you'll want to be in the havit of swinging by a local shop once in awhile and picking up some bits here or there; ebay is your friend! Nab a slow crystal (khz) for redtoring ICs you muffed the timers on and flashed them, and an 8MHz crystal, a 16MHz crystal, a 20MHz crystal (common for atmegas and PICs, for instance.)
  • Capacitor assortment - you can buy start kits that come with 20 or 30 different ratings of caps, in a handy little box; or raid ebay where you can get reidculous packages of a 100 different ratings in a nice little kit.
  • Capacitors for your microcontroller .. I tend to keep some 22pF for the crystal on an atmega, for example, and some mono caps for the 'decoupling' of power (across the + and GND on a micro, or every digital chip really)
  • Resistor assortment - again, ebay is your friend; you can get a little assortment from your lcoal shop or Vellemen or the like, but you can get a pack of 5000 asst from ebay, cheaper.
  • Resistors.. big pile of 10K or 30K for pullup/pulldowns! (setting a 'default value' to a pin, that can be changed when something happens)
  • Maybe a 555 timer
  • Some transitors like the 2222 or an assortment

Techniques

  • Drag soldering - using your solder iron to solder a surface mount many-pinned part (SOIC, SOIJ, QFP, etc)
  • Heat-gun for part recovery
  • Hot air rework station for soldering or part recovery
/home/skeezix/public_html/zikzak.ca/zikzak.ca/dokuwiki/__data/pages/tools.txt · Last modified: 2017/11/11 02:58 (external edit)