Project: MicroLit – Intro and Software

Background

I used Python all the time but I’m normally a bit skeptical about microPython for similar reasons as I am skeptical about Arduino – both of them seem too much like doing hardware from a software approach. Nonetheless it seemed like a reasonable tool for the job in this case.

For my new room I invested in a pair of nice wifi speakers and I want visuals to match so I decided to build an LED controller. Of course, I can buy off the shelf LED controllers, but I want to program my own light patterns and also it’s more interesting to build my own.

I still haven’t got round to shipping all of my equipment from the UK – until this week I didn’t have a multi-meter and I still don’t have my oscilloscope, so I’ll put off talking about hardware for a bit.

I decided to use a BBC microBit which is most easily programmed in microPython. It seems suitable for the job because my lighting is something that I might want to tinker with from time to time, and Python (and so presumably microPython) is quick and easy to iterate. I could build my own microcontroller circuit and program it in C, but really what new would I learn?

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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).

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.