basic reading of battery level (#182)

libs/core/_locales/core-jsdoc-strings.json

@@ -21,6 +21,7 @@
   "brick.Button.pauseUntil": "Waits until the event is raised",
   "brick.Button.pauseUntil|param|ev": "the event to wait for",
   "brick.Button.wasPressed": "See if the button was pressed again since the last time you checked.",
+  "brick.batteryLevel": "Returns the current battery level",
   "brick.buttonDown": "Down button on the EV3 Brick.",
   "brick.buttonEnter": "Enter button on the EV3 Brick.",
   "brick.buttonLeft": "Left button on the EV3 Brick.",

libs/core/_locales/core-strings.json

@@ -28,6 +28,7 @@
   "brick.Button.onEvent|block": "on %button|%event",
   "brick.Button.pauseUntil|block": "pause until %button|%event",
   "brick.Button.wasPressed|block": "%button|was pressed",
+  "brick.batteryLevel|block": "battery level",
   "brick.buttonDown|block": "down",
   "brick.buttonEnter|block": "enter",
   "brick.buttonLeft|block": "left",
@@ -89,6 +90,7 @@
   "{id:group}Buttons": "Buttons",
   "{id:group}Chassis": "Chassis",
   "{id:group}Light": "Light",
+  "{id:group}More": "More",
   "{id:group}Motion": "Motion",
   "{id:group}Screen": "Screen",
   "{id:group}Sensors": "Sensors"

libs/core/battery.ts

@@ -0,0 +1,12 @@
+
+namespace brick {
+    /**
+     * Returns the current battery level
+     */
+    //% blockId=brickBatteryLevel block="battery level"
+    //% group="More"
+    export function batteryLevel(): number {
+        const info = sensors.internal.getBatteryInfo();
+        return info.current;
+    }
+}

libs/core/input.ts

@@ -89,6 +89,14 @@ namespace sensors.internal {
         //serial.writeLine("UART " + port + " / " + mode + " - " + info)
     }
 
+    export function getBatteryInfo(): { temp: number; current: number } {
+        init();
+        return {
+            temp: analogMM.getNumber(NumberFormat.Int16LE, AnalogOff.BatteryTemp),
+            current: analogMM.getNumber(NumberFormat.Int16LE, AnalogOff.BatteryCurrent)
+        }
+    }
+
     function detectDevices() {
         let conns = analogMM.slice(AnalogOff.InConn, DAL.NUM_INPUTS)
         let numChanged = 0

libs/core/pxt.json

@@ -16,6 +16,7 @@
         "png.cpp",
         "screen.cpp",
         "screen.ts",
+        "battery.ts",
         "output.cpp",
         "output.ts",
         "core.ts",