And the version number ticks ever upwards…

The Mitochondrion, Mark 4.1, reached the spinnable stage, but had some irritating flaws. Hence I’m taking that learning into the Mark 4.2, using almost the same hardware and design as the 4.1, but with a new main board. Here I’m testing out the design. You’re looking at an Arduino Nano, 128 kB external memory chip, a combined compass/gyro/accelerometer motion sensor board and the upright bit is a Bluetooth module, all mostly behaving themselves so far.

Oh, and a level shifter, coz one of the things I learnt from the Mark 4.1 was that the motion sensor runs 3.3 Volts internally and has a voltage regulator so you can power it from a 5 Volt supply. However, it also has pull-ups on the I2C communication lines, pulling those up to 3.3 V. If you’re running the rest of the I2C network at 5V, everything all gets very unhappy very quickly.

Progress so far: motion sensing and external memory working just fine and my phone can see the Bluetooth module. Yup, one of the aims for the Mark 4.2 is to control the Mitochondrion from my phone. And for it to act as a thermometer, and possibly portable clock, coz everyone at festivals needs to be reminded that they are up past their bed-time.

Next steps are either getting the audio circuit design tested in hardware, getting the Bluetooth to work from laptop and phone through the software-serial port, refactoring all the software from an OO perspective, or shifting all the floating point maths into fixed point for a dramatic speed up. Coz you know me, I want to make pretty lights turn on and off and clearly the way to do that is not to buy some pretty lights and an on/off switch, but instead to start by writing my own code to perform basic mathmatics, coz other people’s addition and subtractions functions just aren’t good enough.

Hmm… oh, and more skirting boards. Only another 27 metres to go, for which I will be starting with pieces of wood that look nothing like skirting boards.

In other news, I stood under Patrick Herd’s Light with no sense of proportion with Darryl from Firepixie, who is wearing Phoenix Rising pants and comes from the Bay area, hence the excessive interwebnicity:

And we risked the life of The Secret Ruler of the Internet.