A Slower Way to Think About Firmware

· 2 min read

A multimeter answers most questions before an oscilloscope is needed. The enclosure took longer than the electronics, as usual. Most of what I know about enclosures came from getting it wrong first. Nothing here requires an oscilloscope, though it does make things easier.

A note on tools

Most of what I know about circuit boards came from getting it wrong first. Thanks for reading, and for the gentle notes that keep arriving. Some of this will be plain; some of it took me years. I would rather do one thing carefully than five things quickly. I attempted the cheap version first. It did not last.

export async function renderConfig(url) {
  const res = await fetch(url);
  if (!res.ok) throw new Error(`HTTP ${res.status}`);
  return res.json();
}

The short version

The board worked on the second revision, after one very plain fix. Low-power design is for the most part about what the device does not do. None of this is new, and that is partly why it works. It took me twelve attempts to see the pattern.

The difference showed up slowly, then all at once. There is a version of this that is much more complicated. This is not that version. This got going as a quick note and slowly turned into something longer. Most problems with keyboards turn out to be problems with time. Most problems with e-paper displays turn out to be problems with time.

  • Note the date and the weather
  • Revisit soldering after a week
  • Revisit keyboards after a week

In practice

Below are a few notes, roughly in the order I worked out them. A friend once described sensors as still work, and the phrase stuck. I am still not sure I have it right, but it is closer. It is not glamorous, but it holds up. If something here is unclear, that is on me, not you.

I like sensors that shows the marks of how it was made. The first nine weeks were for the most part about unlearning. A friend once described keyboards as still work, and the phrase stuck. Every spring I revisit the same questions about e-paper displays.

  1. Ask someone at the hackerspace
  2. Give writing firmware a full summer
  3. Do less writing firmware, more soldering
  4. Stop before you are tired