Minimize contract, add ADC read and send its data to coonsole

contract/ingest/telemetry.schema.json

@@ -1,46 +1,44 @@
 {
   "$schema": "http://json-schema.org/draft-07/schema#",
   "$id": "contract/ingest/telemetry.schema.json",
-  "allOf": [
-    { "$ref": "contract/ingest/common.schema.json" },
-    {
-      "type": "object",
-      "properties": {
-        "payload": {
-          "type": "object",
-          "required": ["measurements"],
-          "additionalProperties": false,
-          "properties": {
-            "measurements": {
-              "type": "array",
-              "minItems": 1,
-              "items": {
-                "type": "object",
-                "required": ["metric", "value"],
-                "additionalProperties": false,
-                "properties": {
-                  "metric": {
-                    "type": "string",
-                    "minLength": 1
-                  },
-                  "value": {
-                    "type": ["number", "string", "boolean"]
-                  },
-                  "unit": {
-                    "type": "string"
-                  },
-                  "source": {
-                    "type": "string"
-                  },
-                  "ts": {
-                    "type": "integer"
-                  }
-                }
-              }
-            }
+  "type": "object",
+  "required": ["m", "s", "u", "v"],
+  "additionalProperties": false,
+  "properties": {
+    "m": {
+      "type": "string",
+      "minLength": 1,
+      "description": "Metric type (e.g. t=temperature, h=humidity)"
+    },
+    "s": {
+      "type": "string",
+      "minLength": 1,
+      "description": "Source identifier (sensor/channel)"
+    },
+    "u": {
+      "type": "string",
+      "minLength": 1,
+      "description": "Unit (e.g. c, pct, v)"
+    },
+    "v": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "array",
+        "minItems": 2,
+        "maxItems": 2,
+        "items": [
+          {
+            "type": "integer",
+            "minimum": 0,
+            "description": "Delta time (seconds) from base ts"
+          },
+          {
+            "type": "number",
+            "description": "Measured value"
           }
-        }
+        ]
       }
     }
-  ]
+  }
 }