refactor: add an LED indication when displaying the battery voltage o…

…n webpage

.vscode/settings.json

@@ -19,6 +19,7 @@
     "valarray": "cpp",
     "associative_base": "cpp",
     "iterator": "cpp",
-    "serstream": "cpp"
+    "serstream": "cpp",
+    "__locale": "cpp"
   }
 }

_code/measure-battery-level/measure-battery-level.ino

@@ -4,10 +4,11 @@
 #include <WiFiClient.h>
 #include <WiFiAP.h>
 
+#define LED 3
 #define BATTERY_ENABLE_PIN 6
 // FIX: Change pin from GPIO5 (ADC2) to GPIO0 (ADC1)
 // Github Issue: https://github.com/hutscape/capsicum/issues/5
-#define BATTERY_MEASURE_PIN 5
+#define BATTERY_MEASURE_PIN 0
 
 const char *ssid = "batt";
 const char *password = "12345678";
@@ -19,6 +20,9 @@ void setup() {
   Serial.println();
   Serial.println("Configuring access point...");
 
+  pinMode(LED, OUTPUT);
+  pinMode(BATTERY_ENABLE_PIN, HIGH);
+
   if (!WiFi.softAP(ssid, password)) {
     log_e("Soft AP creation failed.");
     while (1) {}
@@ -29,6 +33,8 @@ void setup() {
   server.begin();
 
   Serial.println("Server started");
+  Serial.print("Battery Analog level: ");
+  Serial.println(measureBatteryVoltage());
 }
 
 void loop() {
@@ -39,30 +45,39 @@ void loop() {
     String currentLine = "";
     while (client.connected()) {
       if (client.available()) {
+        digitalWrite(LED, HIGH);
+
         client.println("HTTP/1.1 200 OK");
         client.println("Content-type:text/html");
         client.println();
-        client.print("hello world");
+
+        client.print("Battery Analog Level: ");
+        client.println(measureBatteryVoltage());
+
         client.println();
         break;
       }
     }
     client.stop();
     Serial.println("Client Disconnected.");
+    digitalWrite(LED, LOW);
   }
 }
 
 float measureBatteryVoltage() {
-  pinMode(BATTERY_ENABLE_PIN, OUTPUT);
-  digitalWrite(BATTERY_ENABLE_PIN, HIGH);
-
-  delay(100);
+  pinMode(BATTERY_ENABLE_PIN, LOW);
+  delay(1000);
 
-  int rawValue = analogRead(BATTERY_MEASURE_PIN);
+  int sum = 0;
+  for (int i = 0; i < 100; i++) {
+    sum = sum + analogRead(BATTERY_MEASURE_PIN);
+  }
+  float mean = sum/100.0;
+  float adcValue = mean * (1.1 / 4096.0);
+  float batteryVoltage = adcValue * 11.0;
   // TODO: Fix schematic to use 10k instead of 100k
-  float voltage = rawValue * (3.3 / 4095);
 
-  digitalWrite(BATTERY_ENABLE_PIN, LOW);
+  digitalWrite(BATTERY_ENABLE_PIN, HIGH);
 
-  return voltage;
+  return batteryVoltage;
 }