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).

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HP2VGA: Project Write Up

Introduction

This project started about two and half years ago when I took an FPGA class at MIT and the professor happened to give me an HP1662AS logic analyser that MIT were throwing out. Despite the fact that I lived in the UK and this thing is massive and weighs 20kg I took it anyway. I thought it would be a cool project to replace the cathode ray tube with a larger, LCD display. I thought I would get this done before I left the US three months later… Little did I know it was going to take me another two years (although not of continuous work). Now I am nearly done, and just in time to ship it back to the US when I move back for work.

The HP1662AS on the desk where it was left for me in MIT

Videos: I forgot which way I soldered the chip!

I was soldering a QFN-25 in flip-chip configuration and forgot which way round I soldered it… Here’s how I figured it out.

HP2VGA: PCB Design with a BGA

This PCB represents two firsts for me – first 4 layer board and first BGA package. The former isn’t really a big deal and is really just necessary because of the latter. Due to my memory requirements, I was forced to use the Lattice iCE40HX8k which has more RAM than the smaller variant, iCE40HX4k, and also only comes in BGA packages.

HP2VGA: I’ve Been Making Progress

I haven’t posted in a long time. For one thing, work has been busy. Also I have been making progress here and there in a number of ways, none of which directly merit an article. My solution is to briefly sum up all of my progress here.

Oscilloscope Mod: Decoding My First Frame

It’s been a long time since I last updated about this project, but I have been working slowly in the background. The current plan is to use a TVP7002 from Texas Instruments which is a triple 10-bit video digitiser. It is a little bit over-kill for my needs – it is able to handle three RGB video signals and I only need one monochrome video signal – but nonetheless it is an interesting chip and will achieve what I need.

Multispectral Imaging with Raspberry Pi

Last weekend I went to a meetup which was a bit like a hackathon. The title was ‘Multispectral Imaging with Raspberry Pi’. In a lot of ways I am not a fan of the Raspberry Pi – I feel that it was hyped as a great way to get kids into programming, but in reality most kids have access to full Windows PCs which they will be more familiar with and also have much more user friendly programming IDEs, tutorials etc. What interested me was the multispectral imaging, so I went along not sure what to expect.

They introduced the concept of the Normalised Difference Vegetation Index (NDVI). This is a value indicates the health of plant life and calculate by measuring the light reflected by a plant. It is defined as: