IoT For Makers

 In a previous article, I decided to make a large-sized LED signboard to promote the cafe (BlueBird) and even talked about the process of making the frame. In this article, we will talk about the connection and power of the LED panel, and the connection of the Raspberry Pi.   LED Pannel The LED panel I use is P2.5 128X64. In the figure below, the hole is an M3 standard hole that can fix the panel, and the depth is 5mm. <P2.5 128 X 64 LED Matrix size> There are 128X64 = 8192 pixels in one panel. Therefore, since a total of 24 panels are used, a total of 196,608(192K) pixels are used. An LED signboard of this size cannot be controlled by a single Raspberry Pi.   First Design I plan to control the LEDs using a total of 3 Raspberry Pis. <Configuration> The following figure shows the connection of the top 9 panels. <Top 9 pannels connection> This configuration worked successfully. However, the refresh rate of the screen was around 120Hz. <Top 9 panel test ...

 Recently I opened a cafe specializing in souffle pancakes. The cafe's name is BlueBird and is located in 시흥(Siheung), South Korea. <Cafe indoor scenery> The souffle is made with egg meringue, sugar, butter and it is very fluffy. <souffle pancakes> Now, the corona virus is all over the world. That's why most people are reluctant to go out and reduce access to cafes. My souffle cafe was also affected by this, so the number of customers decreased a lot compared to when I first opened the cafe. So I decided to make a large size LED Matrix that can be installed in windows to promote the cafe. The LED matrix will be made for indoor use and the location of the installation is a window marked with a box in the following picture. <Outside of the cafe> In fact, I have already made a small LED display at the entrance of the cafe. This small LED display was made using Raspberry Pi 4B and three 64x64 LED panels. In the picture below, the top display i...

A few days ago I received four P2.5 126x64 RGB LED matrix ordered from AliExpress. In this blog, I will connect four LED Matrixes to create a 256X 128-sized display. Preparations are as follows. Materials Raspberry Pi 4 : 1 P2.5 128X64 RGB LED Matrix : 4 Electrodragon RGB LED Matrix HAT :1 Hub74 cable : 4 LED Power cable:2 5V power supply : 1 <P2.5 128X64 4EA RGB LED Matrix> <hub75 cable    LED power cable  5V Power supply> RGB LED Matrix HAT setup The 126X64 size RGB LED Matrix is ​​mostly 1/32 multiplexed. Be sure to check the manual of the LED matrix you use for exact details. If you're in 1/32 multiplexing mode, you'll need to tweak some of the Electrodragon HAT's jumper settings. <Electrodragon HAT jumper settings for 1/32 multiplexing> And I'm going to use 2 Hub74 sockets at the same time. Therefore, I will connect the HUB 74 sockets P1, P2 of Electro Dragon HAT together to the LED matrix. <Electrodragon HAT HUB 74 socket P1, P2 are connected ...

Do you know TetrisClock? TetrisClock is a WiFi clock made of falling tetris blocks. Runs on an ESP32 with an RGB LED Matrix. <TetrisClock on the RGB LED Matrix by Brian Lough> I'm a big fan of RGB LED matrix and I wrote many posts about RGB LED Matrix in my blog . I like to display the TetrisClock screen using OpenCV on the Raspberry Pi to the RGB LED Matrix. However, the TetrisClock shown in the figure above works on the Arduino family of ESP32 MCUs. I also posted an article implementing TetrisClock on ESP32 at https://iot-for-maker.blogspot.com/2020/04/led-9-rgb-led-matrix-drive-with-esp-32.html . But I wanted to implement this beautiful clock in Raspberry Pi, so I googled hard, but couldn't find any good examples. Eventually, I decided to analyze the code written in C language and implement it in Python and OpenCV. In my blog, which mainly introduces OpenCV, I introduced 2 articles to implement Tetris characters. Creating TetrisClock using OpenCV #1 Creating Tet...

" 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 ...