Add drafty human friendly current metrics

core/model/src/main/kotlin/org/meshtastic/core/model/util/UnitConversions.kt

@@ -16,11 +16,13 @@
  */
 package org.meshtastic.core.model.util
 
+import kotlin.math.floor
 import kotlin.math.ln
+import kotlin.math.log10
+import kotlin.math.pow
 import kotlin.math.roundToInt
 
 object UnitConversions {
-
     @Suppress("MagicNumber")
     fun celsiusToFahrenheit(celsius: Float): Float = (celsius * 1.8F) + 32
 
@@ -44,7 +46,7 @@ object UnitConversions {
     }
 
     /**
-     * Calculated the dew point based on the Magnus-Tetens approximation which is a widely used formula for calculating
+     * Calculates the dew point based on the Magnus-Tetens approximation which is a widely used formula for calculating
      * dew point temperature.
      */
     @Suppress("MagicNumber")
@@ -53,4 +55,19 @@ object UnitConversions {
         val alpha = (a * tempCelsius) / (b + tempCelsius) + ln(humidity / 100f)
         return (b * alpha) / (a - alpha)
     }
+
+    /**
+     * Converts numbers from milli to unit. examples:
+     * - 1000 milliamperes will be converted into 1 ampere,
+     * - 100 millimeters to 0.1 meters
+     */
+    @Suppress("MagicNumber")
+    fun convertToBaseUnit(number: Float): Float {
+        if (number <= 0) return 0f
+
+        var exponent = floor(log10(number / 1000.0)).toInt()
+        if (exponent.mod(3) != 0 && exponent in -11..11) exponent = (exponent / 3) * 3
+
+        return number / 10f.pow(exponent)
+    }
 }

core/model/src/test/kotlin/org/meshtastic/core/model/util/UnitConversionsTest.kt

@@ -115,4 +115,11 @@ class UnitConversionsTest {
         val zeroHumidity = UnitConversions.calculateDewPoint(20.0f, 0.0f)
         assertTrue("Expected NaN for 0% humidity", zeroHumidity.isNaN())
     }
+
+    @Test
+    fun `convertToBaseUnit converts correctly`() {
+        mapOf(18200f to 18.2f, -4f to 0.004f, 0f to 0f, -9f to 0f).forEach { (number, expectedvalue) ->
+            assertEquals(expectedvalue, UnitConversions.convertToBaseUnit(number))
+        }
+    }
 }

feature/node/src/main/kotlin/org/meshtastic/feature/node/metrics/EnvironmentMetrics.kt

@@ -65,6 +65,7 @@ import kotlinx.coroutines.launch
 import org.jetbrains.compose.resources.stringResource
 import org.meshtastic.core.model.TelemetryType
 import org.meshtastic.core.model.util.UnitConversions.celsiusToFahrenheit
+import org.meshtastic.core.model.util.UnitConversions.convertToBaseUnit
 import org.meshtastic.core.strings.Res
 import org.meshtastic.core.strings.current
 import org.meshtastic.core.strings.env_metrics_log
@@ -374,9 +375,9 @@ private fun VoltageCurrentDisplay(envMetrics: org.meshtastic.proto.EnvironmentMe
                 )
             }
             if (hasCurrent) {
-                val current = envMetrics.current!!
+                val current = convertToBaseUnit(envMetrics.current!!)
                 Text(
-                    text = "%s %.2f mA".format(stringResource(Res.string.current), current),
+                    text = "%s %.2f A".format(stringResource(Res.string.current), current),
                     color = MaterialTheme.colorScheme.onSurface,
                     fontSize = MaterialTheme.typography.labelLarge.fontSize,
                 )