Monthly Archives: April 2016

GMap.NET component : Moving Marker

WTH is GMap.NET?

Simply put: it’s an open source .net component that can show online mapping service (such as Google Map, Bing Map, OpenStreetMap) in your .NET app.
Download the binary here:
Extract it. You’ll get the .net 2.0 and .net 4.0 version, since I’m using VS 2015, we’ll use the .net 4.0 version.

What will we do now is about how to move a marker inside the map (for tracking/visualizing object movement, etc). We’ll just move the marker randomly in this tutorial.

  • Create new VB Windows Form project
  • Add GMap.NET component into your project reference
GMap.NET component reference

GMap.NET component reference

  • Add GMap.NET component into your toolbar.
Add GMap.NET component step 1

Add GMap.NET component step 1

Add GMap.NET component step 2

Add GMap.NET component step 2

  • Now drag and drop the GMap.NET control into your Form, I name it myMap
  • We’ll also add another controls: 1 Button (name: btnMove), 1 Timer (name: tmr1), 1 Label (name: lblInfo)
List of components

List of components

I also add new bitmap resource into our project properties. This will be used as our marker symbol.

Resource for marker symbol

Resource for marker symbol

You can see the Form’s full source code at the bottom of this post. I’ll just point out some important parts:

  • Map initialization is on Form1_Load event code (zoom level, initial position, provider used, marker type, etc)
  • When you click on the btnMove, it’ll start generating new random position for our marker. The random change is happened in the timer event (tmr1_Tick)
  • The process to update the map visual is delegated into function update_map(), so it will run in different thread and the form still responsive
  • In this tutorial, we are using BingSatelliteMapProvider, you can use another provider such as GoogleMapProvider or OviSatelliteMapProvider. Just see MapProviders namespace to see all supported providers.

Running the app

Running the app

Here’s the full source code:

Imports GMap.NET
Imports GMap.NET.WindowsForms

Public Class Form1
    Private Delegate Sub UpdateFormDelegate()
    Private UpdateFormDelegate1 As UpdateFormDelegate

    Private copter_lat, copter_lon As Double
    Private WithEvents copter_marker As Markers.GMarkerGoogle
    Private WithEvents copter_layer As GMapOverlay

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        copter_lat = -7.076275
        copter_lon = 110.428952

        myMap.MinZoom = 5
        myMap.MaxZoom = 20
        myMap.Zoom = 17
        myMap.Position = New PointLatLng(-7.076275, 110.428952)
        myMap.MapProvider = MapProviders.BingSatelliteMapProvider.Instance
        myMap.Manager.Mode = AccessMode.ServerAndCache
        copter_layer = New GMapOverlay("copter_layer")
        copter_marker = New Markers.GMarkerGoogle(New PointLatLng(-7.076275, 110.428952), My.Resources.purple_drone)
    End Sub

    Private Sub tmr1_Tick(sender As Object, e As EventArgs) Handles tmr1.Tick
        Dim delta_lat As Double = ((100 * Rnd()) + 20) / 10000000.0
        Dim delta_lon As Double = ((100 * Rnd()) + 20) / 10000000.0
        Dim not_lat As Single = Rnd()
        Dim not_lon As Single = Rnd()

        If not_lat >= 0.5 Then
            copter_lat += delta_lat
            copter_lat -= delta_lat
        End If
        If not_lon >= 0.5 Then
            copter_lon += delta_lon
            copter_lon -= delta_lon
        End If

        UpdateFormDelegate1 = New UpdateFormDelegate(AddressOf update_map)
    End Sub

    Private Sub btnMove_Click(sender As Object, e As EventArgs) Handles btnMove.Click
        If tmr1.Enabled Then
            tmr1.Enabled = False
            MsgBox("Random Move stop")
            tmr1.Enabled = True
            MsgBox("Random Move start")
        End If
    End Sub

    Private Sub myMap_OnMapZoomChanged() Handles myMap.OnMapZoomChanged
        lblInfo.Text = "Info : Lat= " + CStr(copter_lat) + ", Lon= " + CStr(copter_lon) + ", Zoom Level= " + CStr(myMap.Zoom)
    End Sub

    Private Sub update_map()
        copter_marker.Position = New PointLatLng(copter_lat, copter_lon)
        lblInfo.Text = "Info : Lat= " + CStr(copter_lat) + ", Lon= " + CStr(copter_lon) + ", Zoom Level= " + CStr(myMap.Zoom)
    End Sub
End Class

cygwin: failed to build ArduPilot because of isnan / isinf

Upon building SITL on Windows 10 via cygwin following this tutorial: Setting up SITL on Windows, I encountered build error in this step :

cd ~/ardupilot/ArduCopter
make sitl -j4

Something like these (the original error is very long):

/home/achmadz/ardupilot/libraries/AP_Math/quaternion.h: In member function 'bool Quaternion::is_nan() const':
/home/achmadz/ardupilot/libraries/AP_Math/quaternion.h:51:24: error: 'isnan' was not declared in this scope
return isnan(q1) || isnan(q2) || isnan(q3) || isnan(q4);

So, it seems the libraries is trying to use isnan function but can’t find it.
The solution is quite simple (although I’m not sure if it’s the correct way, but hey.. my solution works!): we edit all .cpp and .h files inside ardupilot/libraries/ folder (and subfolders) and replace all isnan and isinf appearance into std::isnan and std::isinf, for example inside ardupilot/libraries/AP_AHRS/AP_AHRS.cpp line #271, replace:

 if (isinf(_cos_roll) || isnan(_cos_roll)) {


 if (std::isinf(_cos_roll) || std::isnan(_cos_roll)) {

to find files that references isnan and isinf, you can use find command (from within ardupilot/libraries/ folder) like this one:

find ./ -type f \( -iname "*.h" -o -iname "*.cpp" \) -exec grep --color=auto -inH 'isnan' {} \;
find all .h and .cpp files that contain "isnan" reference

find all .h and .cpp files that contain “isnan” reference

and for isinf:

find ./ -type f \( -iname "*.h" -o -iname "*.cpp" \) -exec grep --color=auto -inH 'isinf' {} \;

It’ll show you the files that need to be edited. (You might need to install nano to edit the files — just for convenience).

And done! You are good to go to build SITL in Windows!!

SITL running in windows 10 64bit

SITL running in windows 10 64bit

Test 4G LTE Semarang

[gmap title=”Lokasi percobaan” show_heading=”1″ latitude=”-7.0761649″ longitude=”110.4245947″ zoom=”16″ width=”100%” height=”250px” map_type=”ROADMAP”]
Huawei E3372 (M150-2) Black – MegaFon Version

Indosat Ooredoo

Kekuatan sinyal
Sinyal Indosat Ooredoo di lokasi


Dilakukan beberapa kali dan diambil yang terbaik

Dilakukan beberapa kali dan diambil yang terbaik


Kekuatan Sinyal

Sinyal Telkomsel di Lokasi


Dilakukan beberapa kali dan diambil yang terbaik

Dilakukan beberapa kali dan diambil yang terbaik

CEntos 6.7 Migrating from mysql-server/mysql-community-server into latest MariaDB

Ok, first you should install yum-replace plugin if you haven’t already have it.

yum install yum-plugin-replace

Get MariaDB packages repo from MariaDB repos builder here
MariaDB repo builder
You’ll get some repo config text that you can save to /etc/yum.repos.d/MariaDb.repo like these:

# MariaDB 10.1 CentOS repository list - created 2016-04-17 23:39 UTC
name = MariaDB
baseurl =

Do update your repo chache

yum update

If you’re installing mysql-server from CentOS 6.7 default repo, you should do this:

yum replace mysql-libs --replace-with=MariaDB-common

If you’re installing mysql server from webtatic repo (mysql55w-server), you should do this:

yum replace mysql55w-libs --replace-with=MariaDB-common

If you’re installing from MySQL Community repository, do this:

yum replace mysql-community-common --replace-with=MariaDB-common

Just answer with ‘Y’ if the yum replace command show you some conflicts.
Next, just install all MariaDB related packages:

yum install MariaDB-*

Start MariaDB:

/etc/init.d/mysql start

Confirm that you’re using MariaDB:

[root@www ~]# mysql --version
mysql  Ver 15.1 Distrib 10.1.13-MariaDB, for Linux (x86_64) using readline 5.1

Don’t worry, if you have successfully installing MariaDB over MySQL:

  1. your web app that use MySQL will not broken, no need to change anything
  2. your data will stay intact (no data loss)
  3. use MySQL commands as usual (such as: mysql -u root -p)
  4. the MariaDB config is still in /etc/my.cnf

In short, business as usual!

Blogging again?

Well, it seems that auto-post random post to twitter/Fb is working again and I see my old posts.
Not nice and give some burden to post a new one. Maybe I should begin to post something again.