matt's blog

Free, quality, wire

No, I'm not offering you free wire. Just telling you a good source for free wire.

With the whole world going HDMI these days, there are plenty of obsolete SCART cables around. You probably have some in your attic or garage, mouldering away in a box.

Strip them down. That's right - remove the connectors and the outer rubber casing, and bingo - you have a great selection of wire. Lots of different colour wires, usually in the 22-28 AWG range, and usually pretty high quality as well. And on top of that there's normally a good few lengths of shielded cable too! Bargain!

Filtering WiFi Noise

I recently needed to connect an ESP8266 board up to an audio control and processing board I was working on. And as you can guess the noise was horrendous. Kind of like when you leave your mobile phone near a radio and someone calls you. Pop, pop, crackle, pop pop...

So, some filtering was in order. In the end I came up with this circuit:

Filter

The values can probably be refined somewhat, but I just used components I had lying around.

Serial test sketch

This is a little sketch that I find useful for testing the serial communication on an Arduino-like board. It not only sends data of its own accord (millis() every second), but also echoes back what it receives. That way it will test both transmission and reception, so if one is failing you can easily see.

Arrays? Pointers? What the C?

Arrays and pointers are always a problem for newcommers to C and C++ programmers. Especially if they have come from higher level, more "dumbed down" languages like Java or Basic.

You may think that an array is an array, right? And an array in one language works the same as an array in another language, cus they're, like, arrays, aren't they? Well, you couldn't be more wrong. Certainly when it comes to arrays in C and C++, anyway.

I guess you're probably used to working with arrays like this (pseudocode):

Expected } at end of input error

A common problem, and one that can cause a new programmer to pull their hair out.

However, it's a problem that always has a simple solution, and with the right tricks it's also easy to find where the problem lies.

Let's take the following little code snippet, which throws up this exact error:

1×10³²⁴ things to do with a chipKIT™ Lenny and a QuickIO. No. 2: Virtual Mouse.

Number two in my series of what to do with a Lenny and a QuickIO.

How about a mouse? Yeah, a mouse. Honest :)

Well, maybe not an actual mouse, but maybe make it control the mouse pointer in an "almost" usable way...?

The two potentiometers on the QuickIO could control the mouse position, and the buttons can be the mouse buttons for clicking, etc. That should work.

1x10³²⁴ things to do with a chipKIT™ Lenny and a QuickIO. No. 1: Autoclicker.

This is the first part of a new series entitled "1x10³²⁴ things to do with a chipKIT™ Lenny and a QuickIO". In it, I'm going to be exploring some of the cool things you could do in just a matter of seconds using the two boards combined.

This first one is an Autoclicker.

Configuring Yùn WiFi

It's not always obvious how to configure the WiFi on the Arduino Yùn properly, since most of the good settings are hidden away in the "advanced" interface. So I'll do what I can to expose them to you.

First off, when messing with the WiFi, you really want to be connected to the Yùn using an Ethernet cable (you most probably had one provided with your WiFi router when you got it - it's buried at the bottom of a drawer somewhere).

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