- first commit

apps/chargent/ChangeLog

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+0.01: First version

apps/chargent/README.md

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+# Charge Gently
+
+Charging Li-ion batteries to their full capacity has a significant impact on their lifespan. If possible, it is good practice to charge more often, but only to a certain lower capacity.
+
+The first stage of charging Li-ion ends at ~80% capacity when the charge voltage reaches its peak*. When that happens, the watch will buzz twice every 30s to remind you to disconnect the watch.
+
+This app has no UI and no configuration. To disable the app, you have to uninstall it.
+
+Side notes
+- Full capacity is reached after charge current drops to an insignificant level. This is quite some time after charge voltage reached its peak / `E.getBattery()` returns 100.
+- This app starts buzzing some time after `E.getBattery()` returns 100 (~15min on my watch), and at least 5min after the peak to account for noise.
+
+\* according to https://batteryuniversity.com/article/bu-409-charging-lithium-ion assuming similar characteristics and readouts from pin `D30` approximate charge voltage

apps/chargent/boot.js

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+(() => {
+  var id;
+  Bangle.on('charging', (charging) => {
+    if (charging) {
+      if (!id) {
+        var max = 0;
+        var count = 0;
+        id = setInterval(() => {
+          var d30 = analogRead(D30);
+          if (max < d30) {
+            max = d30;
+            count = 0;
+          } else {
+            count++;
+            if (10 <= count) {  // 10 * 30s == 5 min  // TODO ? customizable
+              // TODO ? customizable
+              Bangle.buzz(500);
+              setTimeout(() => Bangle.buzz(500), 1000);
+            }
+          }
+        }, 30*1000);
+      }
+    } else {
+      if (id) {
+        clearInterval(id);
+        id = undefined;
+      }
+    }
+  });
+})();

apps/chargent/metadata.json

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+{ "id": "chargent",
+  "name": "Charge Gently",
+  "version": "0.01",
+  "description": "Reduces battery wear by buzzing when the first charge stage ended.",
+  "icon": "icon.png",
+  "type": "bootloader",
+  "tags": "battery",
+  "supports": ["BANGLEJS"],
+  "readme": "README.md",
+  "storage": [
+    {"name": "chargent.boot.js", "url": "boot.js"}
+  ]
+}