How To Avoid Using Globals For Information Passing
If you’ve run into the classic noob C programmer’s problem of “Why won’t my function update my variable?” then you might have resorted to using a global variable instead of passing the variable into...
View ArticlePointers As Function Parameters
Suppose you’re writing a function to double a given number. You might naively assume that this would be a reasonable solution: If you run it you’ll find number remains unchanged. This is, you might be...
View ArticleWhy Does My Function Not Update My Variable?
C passes parameters by value – it makes local copy variables of parameters passed into functions. Passing in a pointer means you get a copy of the pointer but that copy is still pointing to the...
View ArticleAvoid Passing Large Chunks Of Data
Because of C’s pass by value semantics, passing data into functions using parameters requires pushing and popping that data onto and off the stack, byte by byte. Using return values to pass data out of...
View ArticleWhy Should I Not Use Pointers?
So if pointers are so great, why not only use pointers? For two reasons, both of which are consequences of the fact that pointers are a method of indirection. Indirection is, at heart, adding a step to...
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Baby’s First Scope
Much as I’d love to have a proper oscilloscope I’m wise enough to know that spending a couple of hundred quid on a cheapo version is probably a bad idea. This is a tool that warrants some significant...
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Pre-assembled Test LEDs
Here’s a nice little idea I saw somewhere a while ago and have just got round to making. It’s just an LED in series with a 470Ω resistor connected to a pair of 0.1″ pitch posts. Whenever you need to...
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Hacking Lego Motors
Lego Technic Power Function motors are nice and easy to hack for robotics projects – in large part because they come with a built in gearbox so you get nice amounts of torque at low speeds right out of...
View ArticleScience Communication Master-class
Remember when mainstream media channels used to act dumb and/or condescending round science? Stephen Colbert is among a growing cadre of broadcasters who gets it right. Here’s the best layman’s...
View ArticleBuild A Computer From Scratch (Kinda Sorta)
I’m currently part way through a fantastic course on hardware design. It’s called Nand2Tetris and walks through building a simulated computer from the very simplest components (individual transistors)...
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