Two weeks ago I made research about available Smart Home Power Sockets. The result was not very positive.
Week ago I discovered talk about ES8266 which seemed to be the right solution.
And what about this week?
I happy to report success. I am able to control the lamp from mobile phone. :-)
This week I bought WeMos D1 Mini WiFi ESP8266 and relay. Together with friend we soldered few pins and wrote some code. The solution was working immediately after we plugged it into a wall.
Here is the result:
Code for Arduino is derrived from esp8266learning.com:
//This example will set up a static IP - in this case 192.168.1.50 #include <ESP8266WiFi.h> const int relayPin = D1; const int chipSelect = D8; const char* ssid = "MYSSID"; const char* password = "SECRET"; WiFiServer server(80); IPAddress ip(192, 168, 1, 50); // where xx is the desired IP Address IPAddress gateway(192, 168, 1, 1); // set gateway to match your network void setup() { Serial.begin(115200); delay(10); pinMode(relayPin, OUTPUT); Serial.print(F("Setting static ip to : ")); Serial.println(ip); // Connect to WiFi network Serial.println(); Serial.println(); Serial.print("Connecting to "); Serial.println(ssid); IPAddress subnet(255, 255, 255, 0); // set subnet mask to match your network WiFi.config(ip, gateway, subnet); WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); } Serial.println(""); Serial.println("WiFi connected"); // Start the server server.begin(); Serial.println("Server started"); // Print the IP address Serial.print("Use this URL : "); Serial.print("http://"); Serial.print(WiFi.localIP()); Serial.println("/"); } void loop() { // Check if a client has connected WiFiClient client = server.available(); if (!client) { return; } // Wait until the client sends some data Serial.println("new client"); while(!client.available()){ delay(1); } // Read the first line of the request String request = client.readStringUntil('\r'); Serial.println(request); client.flush(); // Match the request int value = LOW; if (request.indexOf("/relay=on") != -1) { digitalWrite(relayPin, HIGH); value = HIGH; } if (request.indexOf("/relay=off") != -1){ digitalWrite(relayPin, LOW); value = LOW; } // Return the response client.println("HTTP/1.1 200 OK"); client.println("Content-Type: text/html"); client.println(""); // do not forget this one client.println("<!DOCTYPE HTML>"); client.println("<html>"); client.print("Led pin is now: "); if(value == HIGH) { client.print("On"); } else { client.print("Off"); } client.println("<br><br>"); client.println("<a href=\"/relay=on\">Relay ON</a><br>"); client.println("Click <a href=\"/relay=off\">Relay OFF</a>"); client.println("</html>"); delay(1); Serial.println("Client disconnected"); Serial.println(""); }
That was the easy part. I was able to control relay directly from mobile phone via web browser which was not very convenient. The widget would serve better.
Writing a widget for Android was real challenge. There is very little documentation about it and even Android Studio does not contain template for writing widget. I spent several hours learning how widget works. It is very different from common application.
The very first gotcha that costed me more than a hour was very common problem with builds:
Error:(3) Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.Button.Inverse'.
Yes, it is very clear where is the problem. Or not? :)
It is necessary to fix build.gradle and set proper version of compile dependency. In my case I was targeting API 22, but appcompat was set to 23:
dependencies { compile 'com.android.support:appcompat-v7:22.1.1' }
The real fun begins with the widget code. I cobbled together several chunks of code. Primary source was Obaro’s SimpleAndroidWidget and android-async-http.
Here is the very crude code for Android:
package com.sample.foo.simplewidget; import android.app.PendingIntent; import android.appwidget.AppWidgetManager; import android.appwidget.AppWidgetProvider; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.widget.RemoteViews; import com.loopj.android.http.AsyncHttpClient; import com.loopj.android.http.AsyncHttpResponseHandler; import cz.msebera.android.httpclient.Header; public class SimpleWidgetProvider extends AppWidgetProvider { private void getHttpRequest(String state) { AsyncHttpClient asyncClient = new AsyncHttpClient(); asyncClient.get("http://192.168.1.50/relay=" + state, new AsyncHttpResponseHandler() { @Override public void onStart() { } @Override public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) { } @Override public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) { } }); } @Override public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) { final int count = appWidgetIds.length; for (int i = 0; i < count; i++) { int widgetId = appWidgetIds[i]; String value = "off"; SharedPreferences prefs = context.getSharedPreferences("LampApp", 0); boolean isRelayEnabled = prefs.getBoolean("relayState", false); isRelayEnabled = !isRelayEnabled; SharedPreferences.Editor editor = prefs.edit(); editor.putBoolean("relayState", isRelayEnabled); editor.commit(); if (isRelayEnabled) { value = "on"; } getHttpRequest(value); RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.simple_widget); remoteViews.setTextViewText(R.id.textView, value.toUpperCase()); Intent intent = new Intent(context, SimpleWidgetProvider.class); intent.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE); intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, appWidgetIds); PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT); remoteViews.setOnClickPendingIntent(R.id.actionButton, pendingIntent); appWidgetManager.updateAppWidget(widgetId, remoteViews); } } }
That’s not all. When you want to create widget you need to define also special handling in AndroidManifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.sample.foo.simplewidget"> <uses-permission android:name="android.permission.INTERNET" /> <application android:allowBackup="true" android:label="@string/app_name" android:icon="@mipmap/ic_launcher" android:theme="@style/AppTheme"> <receiver android:name="SimpleWidgetProvider" > <intent-filter> <action android:name="android.appwidget.action.APPWIDGET_UPDATE" /> </intent-filter> <meta-data android:name="android.appwidget.provider" android:resource="@xml/simple_widget_info" /> </receiver> </application> </manifest>
Even that is not enough. You’ll need several small files in res directory including graphics. I won’t describe them here. You can download it from GitHub repo georgik/LampAndroidWidget.
The result?
It works perfectly on Samsung Galaxy S5 Neo, but for some reason I was not able to display this widget on Lenovo K5. If you have any idea why Lenovo K5 has such issue, let me know.
I also discovered a bug in the code of widget. When you have more than one widget it starts turning on and off the relay several times depending on number of widgets ;-)
The solution is ok for the time being. I’m already thinking about using MQTT and Node-Red which was discussed this weekend at OpenAlt conference in Brno by guys from McGayver Bastlíři SH.
hi ,i have one dout
i need print ir reciver value in android app with using of esp8266