Mini Project: Monoprice 3D Printer Modification for Flexible Filament

About a year ago I decided to purchase a 3D printer. I didn’t need anything too fancy, and I didn’t want anything too big. I settled on a Monoprice MP Select Mini 3D Printer V2 which is a small desktop printer for about $200.

I’ve been very impressed with it’s reliability – it has only needed to be tuned once since I set it up, and since then it very rarely fails a print using PLA. But for an upcoming project I want to print in a flexible material, so I ordered some TPU filament from Sainsmart.

Continue reading “Mini Project: Monoprice 3D Printer Modification for Flexible Filament”

Mini Project: Single Pixel

I have an interest in capacitive touch at the moment – I have no particular project in mind but I wanted to see the current state of cap-touch solutions so that I could use it in a future project.

To test it out I made a board with a single touch pixel. I can use this board in other projects as a drop in touch solution. I decided to go with Microchip’s (formerly Atmel’s) qTouch library with their Peripheral Touch Controller (PTC).

Continue reading “Mini Project: Single Pixel”

Mini Project: Guitar Amplifier (old!)

Playing guitar and electronics have been two of my favourite things for a long time now. When I was about 14, I combined these two for the first time and built a pretty simply 32W amplifier. While the design is super simple, it actually has a really nice clean tone and does not distort the sound at all. It’s capable of diving an 8 ohm or 4 ohm load. Today I decided to give it a bit of a clean and check if it still worked.

Continue reading “Mini Project: Guitar Amplifier (old!)”

Mini Project: Reverse Engineering the Samsung Galaxy S2 Touch Screen Interface

This is my last year at university studying for my Masters degree, hence the lack of posts this year – I’ve been pretty busy. My final project involves working with touch screens to improve the signal quality through hardware based processing and the more data I can get, the better. My hope was to intercept the touch screen on a mobile phone to see if I could get to the raw data. I knew that it probably wouldn’t work out that way because most of processing would probably be done by the touch screen controller (TSC) but I thought I’d have a go anyway – a challenge is always fun.

Continue reading “Mini Project: Reverse Engineering the Samsung Galaxy S2 Touch Screen Interface”

WordPress.com Stats Scraper

Something that has been annoying me for a while is that there is no way to download your WordPress.com stats from the website!

So I wrote a script in python to allow you to download all of your stats into a spreadsheet. Here is the guide.

Basically, you need to provide the script with an example XML Http Request (XHR) where the website is pulling stats data from the WordPress.com server. From this XHR, the script then reconstructs a new XHR to get all of the data.

Mini Project: 555 Timer Servo Control

While I wait for parts to arrive for another project, I have decided to fill the time by building a few common circuits that I have never really investigated, even though I know the theory.

One thing that I have never really investigated is the 555 timer chip, despite being a very common “jelly-bean” part. The circuit I built allows a you to control the position of a servo motor by turning a potentiometer – ie, a 50% turn of the potentiometer would result in (approximately) a 50% turn on the servo.

Continue reading “Mini Project: 555 Timer Servo Control”

Mini project: Headphone Music Controls

It’s been a long time since I posted my last update. MIT is keeping me busy – with quizzes every week for the last 5 weeks, as well as the usual helping of classes, problem sets, group projects, labs and reading.

For spring break I flew back to London to visit friends and family, so most of my free time was dedicated to catching up with people back home. But I did find some time to work on a mini project.

The idea was to build a small device that would plug into a phone’s 3.5mm headphone jack and allow me to control music by pressing buttons on the device (play/pause, volume up/down, next/previous track). I actually came up with this idea with a friend at a hackathon in early 2015, but didn’t act on it until now.

This idea isn’t really new either – it’s pretty common for this to be integrated into off-the-shelf headphones. But my headphones don’t have this, and I like my headphones.

With a little research I was able to uncover the Android specification for devices like these.

headset-circuit2

A colourful example of an implementation for Android. Source.

Continue reading “Mini project: Headphone Music Controls”