But - fuck me! - the documentation is atrocious! Well, that's a lie. There is no documentation. It has the "Chat to us on Discord" anti-pattern that infects so many otherwise great projects.

So I'm left to figure out how to make the Watchy's haptics work.

The example watchfaces have a file called settings.h which contains .vibrateOClock = true. Set that and you'll get a little buzz on the hour, every hour.

But how do you make it buzz when you've hit your step-count goal? Or when the time is 13:37? Or whenever you want?

There's no documentation. And searching the code for "vibrate" or "vibe" or "vibration" yielded nothing. But I accidentally typo'd my search and entered "vib" - and that did the trick.

In config.h there's this line: #define VIB_MOTOR_PIN 13.

So, pin 13 is wired in to the vibration motor. We can add that line to our own config file. But how do we turn the buzzer on and off?

With a bit of help from Discord, it became clear:

pinMode(VIB_MOTOR_PIN, OUTPUT);     // Set vibration motor pin as an output.
digitalWrite(VIB_MOTOR_PIN, true);  // Enable vibration motor
delay(150);                         // Vibe for 150 ms.
digitalWrite(VIB_MOTOR_PIN, false); // Disable vibration motor.
delay(500);                         // Wait half a second
digitalWrite(VIB_MOTOR_PIN, true);  // Enable vibration motor
delay(250);                         // Vibe for quarter of a second
digitalWrite(VIB_MOTOR_PIN, false); // Stop vibrating

That's the same as the HTML5 Vibrate API - you can't control the intensity, but you can program your own vibration patterns.

I just don't understand why hardware vendors are so crap at writing documentation. Don't they like people using their products?