Initial Commit

.gitignore

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+.vscode

README.md

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+# Liebhab Licht
+
+Have you ever been in a long distance relationship and wanted to let your partner know, you're thinking of them? 
+
+Building on an inexpensive night light, this code base allows you to send messages in the form of light pulses via a web UI to your partner.
+
+
+![Web UI](img/web_ui.png)
+
+## Quickstart
+
+## Hardware
+TODO
+
+## Software
+TODO
+
+

esp32/.gitignore

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+arduino_secrets.h
+
+# Created by https://www.toptal.com/developers/gitignore/api/linux,c++
+# Edit at https://www.toptal.com/developers/gitignore?templates=linux,c++
+
+### C++ ###
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app
+
+### Linux ###
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+# End of https://www.toptal.com/developers/gitignore/api/linux,c++

esp32/arduino_secrets_TEMPLATE.h

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+// Secrets File
+// contents will be injected to esp32.ino at build time
+
+// WIFI credentials
+#define WIFI_SSID "<WIFI SSID>"
+#define WIFI_PASSWORD  "<WIFI-PASSWORD>"
+#define ROOT_CA  "<ROOT CERTIFICATE>"
+
+// liebhab.maxfruehauf.com user credentials
+#define AUTH_USERNAME "<USER>"
+#define AUTH_PASSWORD "<PASSWORD>"
+#define API_ENDPOINT "<API_ENDPOINT>"

esp32/esp32.ino

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+#include <WiFi.h>
+#include <HTTPClient.h>
+#include <ArduinoJson.h>
+#include <base64.h>
+
+#include "arduino_secrets.h"
+
+//
+// WiFi params
+//
+const char *ssid = WIFI_SSID;
+const char *password = WIFI_PASSWORD;
+
+//
+// Server params
+//
+const String authUsername = AUTH_USERNAME;
+const String authPassword = AUTH_PASSWORD;
+const char *endpoint = API_ENDPOINT;
+const char *root_ca = ROOT_CA;
+
+//
+// Light Params
+//
+#define SWITCH_PIN 13
+#define ADC_PIN 32
+// if light is currently on
+bool light = true;
+bool light_target = true;
+// power reading params
+#define MW_THRESHOLD 100.0
+
+//
+// Misc Params
+//
+#define WIFI_RETRY_MS 10 * 1000
+#define WAIT_MS 3 * 60 * 1000
+#define ERROR_RETRY_MS 10 * 100
+
+//
+// ArduinoJSON params
+//
+#define ARDUINOJSON_USE_LONG_LONG 0
+#define ARDUINOJSON_USE_DOUBLE 0
+
+// WIFI
+void connect_wifi()
+{
+  WiFi.begin(ssid, password);
+
+  while (WiFi.status() != WL_CONNECTED)
+  {
+    delay(1000);
+    Serial.println("Connecting to WiFi..");
+  }
+  Serial.print("Connected to the WiFi network ");
+  Serial.println(ssid);
+}
+
+/*
+True if the light is consuming more power than the threshold
+*/
+bool is_on()
+{
+  int adc_value = analogRead(ADC_PIN);
+  float mV = ((float)adc_value) / 4095 * 3.3 * 1000;
+  float mW = mV * 5;
+  light = mW > MW_THRESHOLD;
+  return light;
+}
+
+/*
+Pulses SWITCH_PIN once (active low)
+*/
+void pulse()
+{
+  digitalWrite(SWITCH_PIN, LOW);
+  delay(100);
+  digitalWrite(SWITCH_PIN, HIGH);
+}
+
+/*
+Toggles the light, insuring that the desired target state
+is reached by measuring the consumed power.
+*/
+void toggle_light()
+{
+  // update target state
+  light_target = !light_target;
+  Serial.print("Toggling light: ");
+  Serial.print(light);
+  Serial.print(" -> ");
+  Serial.println(light_target);
+
+  while (light != light_target)
+  {
+    pulse();
+    // wait 2s to let light state settle.
+    delay(2000);
+    // measure power consumption
+    is_on();
+
+    Serial.print("try toggle, light_state: ");
+    Serial.println(light);
+  }
+  Serial.print("toggled light state: ");
+  Serial.println(light);
+}
+
+void setup()
+{
+  Serial.begin(115200);
+  pinMode(SWITCH_PIN, OUTPUT);
+
+  connect_wifi();
+
+  // setup light toggle
+  light = true;
+  toggle_light();
+}
+
+void loop()
+{
+  // Check the current connection status
+  if ((WiFi.status() != WL_CONNECTED))
+  {
+    connect_wifi();
+    delay(WIFI_RETRY_MS);
+  }
+
+  // connect to endpoint
+  HTTPClient http;
+  http.begin(endpoint, root_ca);
+
+  String auth = base64::encode(authUsername + ":" + authPassword);
+  http.addHeader("Authorization", "Basic " + auth);
+
+  const int httpCode = http.GET();
+  if (httpCode != HTTP_CODE_OK)
+  {
+    Serial.print("Unexpected return code: ");
+    Serial.println(httpCode);
+    http.end();
+    delay(ERROR_RETRY_MS);
+    return;
+  }
+
+  // read payload
+  String payload = http.getString();
+  // Free HTTP ressources
+  http.end();
+
+  Serial.print("Got messages form server: ");
+  Serial.println(payload);
+
+  if (payload == "[]")
+  {
+    // Serial.println("Array has 0 elements, skipping");
+    delay(ERROR_RETRY_MS);
+    return;
+  }
+
+  // deserialize JSON
+  StaticJsonDocument<384> doc; // size computed with https://arduinojson.org/v6/assistant/
+  DeserializationError error = deserializeJson(doc, payload);
+  if (error)
+  {
+    Serial.print("ERROR: Could not deserialize json: ");
+    Serial.println(error.c_str());
+    delay(ERROR_RETRY_MS);
+    return;
+  }
+
+  JsonObject root_0 = doc[0];
+  bool sent_out = root_0["sent_out"];
+
+  if (!sent_out) {
+    Serial.println("Message sent out not true");
+    delay(ERROR_RETRY_MS);
+  }
+
+  // turn light on and off again
+  Serial.print("Light on for ");
+  Serial.print(WAIT_MS);
+  Serial.println(" ms");
+  toggle_light(); // on
+
+  delay(WAIT_MS);
+
+  toggle_light(); // off
+}