1. The other detail added to : phoning via SIP and a “Call Me” button. On desktop devices you’ll see it on my homepage in the Elsewhere section. Clicking it on a WebRTC-enabled browser will start an audio call with me if I’m logged into a SIP client.

Next: using a Tropo app as a middleman for providing voicemail transcription and local numbers, improving/providing mobile UI.

2. # Notes vs Articles, again

After deliberating a little about how to “do” a composite homepage feed, whether or not I should forget about having “notes”, “music” and “articles” and just merge them all, coupled with the fact that I already use notes for replies, I have reached a simple conclusion, of which this post is the first demonstration.

/notes/ and what used to be “Notes” is now my de-facto dump for short-medium length chronological posts of all types. This covers notes, replies, checkins, short articles (basically named notes with more structure) and so on. Posts with a name live at /notes/DDD-name, those without names live at /notes/DDDSSS.

/articles/ retains all content which lived there in the past. Going forward it might become more of a wiki, or a place for very long things like Data Export.

/music/ will retain all it’s content, and be where I post standard musical notation tunes. Audio recordings of those tunes will be posted as audio posts with a link to the relevant tune.

Hopefully these changes, along with improved templating (post-type-specific DOM templates here I come) will make finding, posting and reading posts on a much more pleasant experience.

3. # Voltage Dividers

Working through some example circuit simulations I finally gained an intuitive understanding of the voltage divider equation — it’s just a ratio, but I had never figured this out before.

Given this circuit, where the voltage source is rated at 1V:

The voltage at A is equal to 1V·(R2 / R1 + R2), which is 1·(1/1+1) = 1·(1/2) = 0.5.

Why? Because R1 + R2 represents the total resistance of the path, and as such the total voltage drop. Dividing R2 by the total produces a fraction representing the voltage drop over R2. Multiplying the input voltage by this fraction leaves us with the voltage dropped over just the R2 portion of the circuit, which must be VA because there are no other branches in the circuit.

Put another way, the equation finds the ratio of resistance (and so voltage drop) R2:R1 and then feeds the input voltage through this. Here’s a more abstract visual representation of what’s going on:

4. “Fail Fast” is the trendy alliterative buzzword version of “have small feedback loops”, just less accurate and more prone to undesirable misinterpretations.

5. Emil Björklund: #PHP folks: when fetching from an API, would it be wise to use function_exists to check for cURL, and else fall back to file_get_contents()?

@thatEmil that should work fine — one thing to bear in mind is that by default they both treat redirects differently. IIRC, cURL doesn’t follow redirects by default whereas file_get_contents will.

6. Having a go at making Sumendi’s leche frita (fried milk). Just put the mix in the fridge, pretty sure the consistency is perfect, but I’ll find out for sure tomorrow!

7. Sandeep Shetty: @BarnabyWalters Very cool. What's the use-case though? Also is this coming of the doctrine based indexer that you had?

@sandeepshetty thanks! I’ve wanted to plot tag usage over time for a while now to see if there are any interesting patterns. I’m not using doctrine any more, in fact I’m not even using a SQL database for indexing until I really need one — data stored in yaml files, indexed by a csv file in ~210 lines of code — see also waterpigs.co.uk/notes/4TQNY2

When I post a note, adds one to the week counter for each tag, then I have an endpoint which makes that data into an SVG.