[EN] Arduino : ESP8266 GPIO

In this article, we will learn about GPIO (General Purpose I/O) or pin connect to an external device of microcontroller with C++ of Arduino using esp8266 as reference chip. This can be applied to Arduino Uno, Arduino Mega or STM32 as well. Under this article, we describe the duty of the pin,  output and the input signal.

(Figure. 1 GPIO of WeMos D1)

[EN] ESP8266WiFi

This article is a compilation of information related to the ESP8266WiFi class, which performs the WiFi functionality of the ESP8266 microcontroller. This class can be accessed via a WiFi object, which is an object created for accessing the chip’s wireless module and must import a header file named ESP8266WiFi.h

[EN] WiFiServer

After studying the ESP8266WiFi to control the microcontroller connected to a wireless network in an STA and SoftAP form, then learned how to use the WiFiClient to use the esp8266 as a client node. This time, it’s about WiFiServer to make esp8266 act as a service node or Server. The example in this article is to create an internal network system by using 3 esp8266 to act as SoftAP, Server and Client as shown in Figure 1.

[EN] SPI Bus

This article discusses the SPI bus functionality of the Arduino framework for use with the STM32F030F4P6, STM32F103C8, STM32F401, esp8266 and esp32. The operation of this bus requires at least 3 intercommunication cables: SCLK, MISO. and MOSI for transmitting the clock signal between the sender and the receiver. It serves to receive information from the sender. and used for sending information to the recipient.

From the use of 3 signal lines, it is found that data can be transmitted and received simultaneously. This is different from I2C bus communication that uses only one SDA cable to communicate. At the same communication speed, the SPI bus will receive and transmit data without waiting for an idle line, while I2C will have to wait for idle. With this in mind, SPI can send/receive data faster.

In addition, SPI uses a method to select the destination to communicate by instructing the endpoint to know by sending a signal to the SS pin of the terminal. Therefore, when connecting to multiple devices, SPI requires a larger number of pins to operate, while I2C uses device identification to communicate with each other by still using only one SDA cable, which saves more pins.

[EN] I2C Bus/Wire.h

This article describes the methods of Wire.h, a class for communicating with devices over an I2C bus that uses two signal wires called SDA and SCL to transmit data between them. We have quite a number of articles about this type of communication and used as the main bus to develop devices by yourself and run through the bus, for example, articles on using esp8266 to connect to Arduino Uno or using esp8266 with stm32f030f4p6, etc.

[TH] LittleFS Filesystem

บทความกล่าวถึงการใช้ไลบรารี LittleFS และแนะนำไลบรารีที่ถูกพัฒนาเพื่อใช้กับไมโครคอนโทรเลอร์ esp32 ซึ่งมีส่วนเสริม (plugin) ของ Arduino IDE สำหรับอัพโหลดไฟล์ไปเก็บในรอมของไมโครคอนโทรลเลอร์ ทำให้สะดวกต่อการโหลดข้อมูลไปเก็บและเรียกใช้งาน ด้วยเหตุนี้ถ้าผู้เขียนโปรแกรมรู้สึกยุ่งยากกับการแปลงโค้ด HTML/CSS/JavaScript ให้เป็นสตริงด้วยตนเอง และเปลี่ยนมาเป็นอัพโหลดไฟล์ไปเก็บใน esp32 แล้วอ่านไฟล์เว็บมาใช้งานโดยตรงจะเป็นสิ่งที่จะต้องฝึกฝนใช้งานเจ้า LittleFS ไว้เป็นไลบรารีคู่ใจกันเลยทีเดียว


[EN] Arduino : DHT Sensor

This article describes how Adafruit’s DHT Sensor library is compatible with all Arduino-compatible architectures, making it easier to deploy DHT sensors for humidity and temperature readings across multiple platforms. This article has tested with ESP32, ESP8266, Arduino UNO and stm32f103c and found that it can be used without modifying the code in the working part or having to modify the source code to make it compatible with the platform.

(Figure. 1 dht22 and BluePill)

[EN] Arduino : RTC DS1302

From the article programming Python on Micropython to use RTC number DS1302, this time, we change the programming language to C++ for Arduino by using STM32F030F4P6 Cortex-M0, esp8266 and Arduino Mega as a worker instead of ESP32 as shown in Figures 1, 2 and 6 by show the report on the RS232 port to display the date and time as shown in Figure 4.

(Figure. 1 DS1302 experiment with STM32F30F4_6.)