Name: HR Zone Gauge Index
Rating: 5 (1 reviews)
Author: droidgren

A heart rate zone gauge that fills the space it is given — a full ring, a half ring, or a bar — and shows your zone as a decimal index, a heart rate, or a percentage of your maximum.

This project is completely free and built for the community. If you find it useful and want to support continued development, buying me a coffee is a great way to help.
Use this link below to donate: https://ko-fi.com/droidgren

HR Zone Gauge Index shows how hard you are working at a glance, using the heart rate zones you have already configured on your watch.

Instead of only telling you which zone you are in, it shows how far through that zone you are. Zone 3.5 means you are halfway between the bottom and the top of zone 3 — the kind of detail a plain zone number hides.

It fits the layout you use. Out of the box there is nothing to configure; the field looks at the space the activity profile gives it and picks a shape:
• A full-screen field on a round watch draws a 270° ring with the opening at the bottom.

• A half-height field draws a 180° half ring, concentric with the display so it follows the curve of the bezel: an arch in the upper slot, a bowl in the lower one.

• The outer rows of a three- or four-field layout are bounded by the display curve, so the gauge follows it as a shallow arc against the bezel, with the value in the rest of the row.

• A middle row, or a quadrant of a round watch, draws a flat segmented bar with the value beside it.

• On an Edge and the other rectangular devices the field has no way to tell how much of the screen it covers, so it goes by the shape of the space alone: a tall enough field draws the ring, a short one the bar.

Five settings, all in the Garmin Connect app.

• Gauge Design — Auto (default) picks the shape as described above. Gauge asks for the arc wherever one is readable, including places Auto would have drawn the bar; a space too shallow for any arc still gets the bar. Bar keeps the flat bar everywhere, even on a full screen.

• Displayed Value — what the number in the middle shows: Zone index (default), for example 3.5; Heart rate, for example 161; or Percent of max HR, for example 86%.

Gauge Zones — how much of your zone range the gauge covers:
• Current (default): the gauge covers only the zone you are in and rescales every time you change zone. If zone 3 is 150–165 bpm, the gauge runs from 150 to 165 in green; cross into zone 4 and it restarts near empty in orange. Best when you are trying to hold a zone.

• Z1-Z5: all five zones as fixed coloured segments, grey through to the top zone, with a marker showing where you are. The zone you are in is drawn at the full thickness of the band and the rest a little shallower, so it stands out at a glance. On the AMOLED watches the segments use Garmin's own zone colours; the transflective displays use a palette picked for their more limited colour range.
• Z4-Z5: just the top two zones, for interval and threshold work where the lower zones are not interesting.

Color value by Zone — off by default, which draws the number in white or black. Turned on, the number takes the colour of the zone you are in, matching the gauge, and goes back to plain whenever there is no zone to colour it by.

Count values below Zone 1 (Zone 0) as Zone 1 — your zones start partway up the range, so zone 1 might begin at 93 bpm of a 186 max, and anything under that has no Garmin zone at all. On by default, that range counts as zone 1 and the gauge tracks it instead of pinning the marker at the far left, with the index reading 0.1 through 1.9 rather than starting at 1.0. Turned off, it is a neutral grey zone of its own, off the bottom of the scale. Either way the index recorded to your FIT file is the same.

Recorded to your FIT file. The decimal zone index is written as a developer field called HR Zone Index, whichever value you have chosen to display, so you can analyse it in Garmin Connect or any FIT tool afterwards.