Saturday, August 11, 2018

DIY Programmable Function Generator Using Arduino Uno

It is possible to use Arduino Uno as a function generator to produce low frequency waveform. The advantage of the approach is the possibility of producing customized, complex, time varying waveform. On the down side, it cannot produce waveform with very high frequencies. To get smoother waveform, the PWM output frequency of pin 3 of Arduino Uno is increased to approximately 8 kHz. It is also possible to use DAC to achieve better results.

Figure. The output of Arduino function generator measured with an oscilloscope.

Friday, August 10, 2018

Using MySQL Database with C++ on Various Platforms Including ARM Single Board Computers

In this article, I would like to discuss about using MySQL database with C++. MySQL is an open source database management system from Oracle. It not only has freely available version but it is also robust and works on most platforms. MySQL server can run even on a small 32 bit ARM Single Board Computer (SBC) like Odroid. It has a lot of functionalities, and user interface too. That is why, I like to use MySQL database server as an example to be used with C++.

MySQL server can be used as a traditional relational database or a document store where there is no need to define schema, called NoSQL. In a relational database, all the columns of the tables need to be defined in advance. But in a document store, the schema is flexible where it is represented by JSON objects. In order to utilize the advantages of power of relational model and flexibility of the document store, using X DevAPI in C++ applications is discussed.