IoT For Makers

" ESP32  is a series of low-cost, low-power  system on a chip   microcontrollers  with integrated  Wi-Fi  and dual-mode  Bluetooth . The ESP32 series employs a  Tensilica   Xtensa LX6  microprocessor in both dual-core and  single-core  variations and includes built-in antenna switches, RF  balun , power amplifier, low-noise receive amplifier, filters, and power-management modules. ESP32 is created and developed by  Espressif Systems , a Shanghai-based Chinese company, and is manufactured by  TSMC  using their 40 nm process. [2]  It is a successor to the  ESP8266  microcontroller. " <from https://en.wikipedia.org/wiki/ESP32 > ESP32 is a Dual Core MCU The predecessor of ESP32, the ESP8266 has a builtin processor. However due to multitasking involved in updating the WiFi stack, most of the applications use a separate micro-controller for data processing, interfacing sensors ...

So far, many Python examples have been created to use the LED matrix. And most of them worked by using ssh remote access or directly connecting a local monitor and keyboard to the Raspberry Pi. However, there is one major drawback to this type of work. There is no scenario management function. Most LED signboards show multiple sentences or images repeatedly in sequence, depending on the conditions. Therefore, we need a tool to properly run the Python files for controlling our LEDs. A suitable tool for this purpose is Node-RED. Node-RED is a flow-based development tool for visual programming developed originally by IBM for wiring together hardware devices, APIs and online services as part of the Internet of Things . [2] Node-RED provides a web browser -based flow editor, which can be used to create JavaScript functions. Elements of applications can be saved or shared for re-use. The runtime is built on Node.js . The flows created in Node-RED are stored using JSON . ...

In a previous post, I showed you how to display a variety of non-English languages ​​on an LED matrix. In this post, I will look at displaying colorful text that has been image-processed on the LED, rather than just displaying simple text. The image processing content introduced in this article is related to the previous post and https://opencvcooking.blogspot.com/2019/12/basic-cooking-2-pil-text.html . Outline Text Outline text is the text extracted from the outline of the font as shown in the following figure. gimp and other image editing tools make it easy to create outline text images. Let's see how to make it using PIL. In the previous OpenCV blog, the results of the processing were output to a computer screen or file, but this time to the LED matrix. <Outline text Example> See the previous post on how to handle fonts in PIL. import argparse import time , os from PIL import Image, ImageDraw, ImageFont from rgbmatrix import RGBMatrix, R...