This article is about programming C/C++ with Arduino Nano, Arduino Uno, LGT8F328P or other boards with C-capable platforms. A pointer is used to point to a memory address and memory management methods, including memory reservation memory access and deactivating the use of memory to create a method for storing data in a Single Linked List along with an example program used to store a list of temperature and humidity values from the DHT11 module as shown in Figure 1.
Figure 1 Microcontroller with LGT8F328P and DHT11 module
From the article on how to use u8g2 that can render Thai string through the drawUTF8() function of the u8g2 library, the rendering is not correct as shown in Figure 1, therefore, the code of libraries needs additionally adjusted to render correctly as in Figure 2.
Figure 1 drawUTF8() display before adjustmentFigure 2 drawUTF8() after adjustment
The article discusses the use of the LittleFS library and introduces a library developed for use with the esp32 microcontroller, which includes a plugin for the Arduino IDE for uploading files to the microcontroller’s ROM. Make it convenient to load data to store and run. For this reason, if programmers find it difficult to transcode HTML/CSS/JavaScript to be a string manually and switching to uploading files to esp32 and reading the web files directly to use will be something that will require training to use LittleFS as a reliable library.
In the previous article, programming to implement queue-based data structures was introduced. In this article, we introduce programming to manage another type of data structure which has different storage and management methods called BST tree or Binary Search Tree, as shown in Figure 1, which is a structure that can be applied to data collection with attributes in which the data in the left branch is less than itself and the right branch is greater than itself or the opposite, i.e. the left branch has a greater value and the right branch is less. It enables searching for data in cases where the tree is balanced on the left and right in the BST structure, saving half the time or number of search times per round of available data, e.g. 100 data sets in the first round if it is not the information you are looking for will be left with a choice to find from the left or right branches which the selection causes the information of the other side is not considered or cut off approximately half. However, if the Binary Search Tree is out of balance, the search speed is not much different from the sequential search.
In this article, we use Python that works on either a Python 3 or MicroPython interpreter to store the data, adding information ,searching for information as an example of further development.
