Just Sharing Knowledge on Robotics, Electronics and Programming

Sunday, August 26, 2018

[SOLVED] Xamarin Studio Android SDK Not Found ... Searched Windows Registry

If you use Xamarin Studio For the first time, i suggest you to create a very simple apps that is two click. then test your project. if you face the following error :

SetUp : System.Exception : Android SDK not found. Please install it and if it is still not located, please set the ANDROID_HOME environment variable to point to the directory.
Searched locations:
Windows Registry
(No path) - Not set. [ Source: ANDROID_HOME ]


SetUp : System.Exception : Java Development Kit (JDK) not found. Please make sure that it is installed and if it's still not located, please set the JAVA_HOME environment variable to point to the directory.

Searched locations:Windows Registry
 [ Source: JAVA_HOME ]

then use the following solutions (see the picture),
1. Go to this pc and Right -click then click properties

Friday, August 24, 2018

[SOLUTION] Select Database The N numbers Last or First Rows in Codeigniter

If you want to select the N last rows or N first rows, in codeigniter you can use the following script

$n = 100;
$this->db->order_by("id", "desc"); // N last rows 
$query = $this->db->get('my_table');
$myRow = $query->row();
$n = 100; 
$this->db->order_by("id", "asc"); // N first rows 
$query = $this->db->get('my_table');
$myRow = $query->row(); 

Friday, August 17, 2018

[ Research ] Autonomous Land Vehicle In Progress

We are currently research the Automomous Land Vehicle in Institut Teknologi Sumatera, Indonesia. The Autonomous system is using GPS to obtain location of vehicle and using PID control in steering system and position tracking system.


The progress of research is still 40% complete. we are still researching in control and web based control station.

Tuesday, August 14, 2018

[SOLVED] HMC5883L not working ( i2c adress:0x0D instead of 0x1E )

do you buy HMC5883L but the device not working?
if yes, you should check the i2c adress by using i2c scanner. --link--

if in i2c scanner you found device address is  0x0D then your trouble is wrong library, but if terminal say i2c not found, the problem is on hardware connection.

if address is 0x0D this is different with hmc5883L because this module is using qmc5883L ic. so the library is different with hmc5883L library.

To solve this issue, you can use the following library to work with your compass module.

Download Qmc5883L library