Monthly Archives: September 2015

My First Raspberry Pi HAT

I’m a bit late in reporting on this, because much of the work happened over the Labour Day weekend, waiting in ferry lineups and such.  I spent too much time poring over datasheets, double- and triple-checking my design, and while I’m still not sure that it’ll work, I’m going ahead with the first revision of my first Raspberry Pi HAT.

My first HAT is intended to be a part of the Office Robot.  But I can see some other potential uses for it, so I tried to make the design a little more flexible.

Designed Features:

  • Mono microphone input
  • 3.7W stereo speaker output
  • SPI peripheral connector, with an interrupt and reset line
  • I2C peripheral connector, with shared interrupt and reset lines
  • 5V power input
  • Power control button

I am confident that the level-shifted peripheral connectors will work properly, as I’ve prototyped both on a breadboard.  It’s the audio stuff I’ve never played with before, that I’m nervous about.  But even if those bits don’t work properly, the HAT will still be a lot cleaner than the breadboard covered in jumper wires.

I’ve got my fingers crossed, but if I have to build Version 2, I’m okay with that, too.

 

Apartment living, and hobbies

It turns out, living in an apartment and trying to manufacture things, can be a bit of a challenge.  I’ve spent the last two days tiptoeing around a plastic painter’s dropsheet, upon which are pieces of trackbed for the Office Train.

I’ve been holding off on doing any further work on the train, since I’m told that a desk shuffle is imminent.  But then I remembered that I made all the pieces so that they’d match the length of the modular cubicle walls.  And as long as I install the flex track, cut to match, the trackbed pieces can be easily moved and adjusted!

But more importantly, I’ll finally get this pile of wood out of my cramped living quarters!