K82 USB CDC Virtual Comm

In this article, we will discuss about using K82 as a USB CDC virtual com device. Setting up environment for K82 development is discussed in previous article at the following link.

http://cool-emerald.blogspot.com/2020/01/getting-started-with-frdm-k82f.html

• SDK VCom Example
• Ring Buffered VCom

Software timers and Ring Buffered UART Com for Kinetis K82 MCU

In this article, I would like discuss about using Kinetis K82 MCU with MCUXpresso IDE. I will use FRDM-K82F development board as a hardware platform. Setting up environment for K82 development is discussed in previous article at the following link.

http://cool-emerald.blogspot.com/2020/01/getting-started-with-frdm-k82f.html

• SDK Example
• Soft Timers
• Com

DrawBot XY Plotter with Arduino GRBL Controller

In this article, I would like to discuss about using DIY XY plotters which are also called draw bots. You can buy them at online stores such as LYCNC store or Global Tech. Factory Store on Aliexpress.

• Overview
• Controller
• Calibration
• Drawing

C++ REST SDK

C++ REST SDK is for cloud based client server communication using C++ API design [1].

• Setting up
• Simple GET Client
• POST Client
• CppREST Server
• GUI Multithreaded Examples

Cross Compiling C++ Programs for Raspberry Pi that Uses Static or Shared Libraries Such as OpenCV and wxWidgets

In this article, cross compiling C++ programs for Raspberry Pi on Ubuntu Linux system is discussed. We use "schroot" to avoid messing the main system and to get clean build environment.

• Setting up
• Using schroot
• Building a Simple Program
• OpenCV
• wxWidgets

Using Orange Pi

Orange Pi is a cheap alternative to Raspberry. They can be bought at their online store Shenzhen Xunlong at Aliexpress. There are many Orange Pi models. For example, Orange Pi One costs only ~USD 10. Another model called Orange Pi PC Plus even has 8 GB eMMC onboard and costs ~USD 25 only.

Figure. Orange Pi One

• Setting Up
• Desktop
• eMMC
• VNC Server
• Linux Headers
• GPIO

Tesseract OCR with C++, OpenCV, and wxWidgets

Tesseract is a free optical character recognition software and it is considered one of the most accurate open-source OCR engines [1].

• Installation on Ubuntu
• Using tesseract command
• Tesseract C++ API with OpenCV
• With wxWidgets

Getting Started with FRDM-K64F

To use FRDM-K64F with the latest MCUXpresso IDE, you need to update the firmware for its debugger. It is similar to FRDM-K82F where the details can be seen at the following post.

http://cool-emerald.blogspot.com/2020/01/getting-started-with-frdm-k82f.html

There are only a few minor difference between FRDM-K64F and FRDM-K82F to get started. Therefore, I will only list some major points here.

Figure. FRDM-K64F board

Original OpenSDA appears as MBED drive. And it is not working with MCUXpresso. To update the firmware for its debugger,

• Disable 'Windows storage services' ( https://os.mbed.com/blog/entry/DAPLink-bootloader-update/)
• Hold reset button and connect the device to a USB port. It should now appear as a drive called BOOTLOADER
• Drag and drop bootloader ‘0244_k20dx_bootloader_update_0x5000.bin’ into the drive.
• Remove and reconnect without holding reset. Board shows as ‘MAINTANCE’.
• Drag and drop Segger jLink OpenSDA for board specific firmware for K64F (‘02_OpenSDA_FRDM-K64F.bin’) which is available at https://www.segger.com/downloads/jlink#JLinkOpenSDABoardSpecificFirmwares
• Remove and reconnect without holding reset button. It now appears as ‘FRDM-K64FJ’
• To use JLink , open cmd and enter
  
  

  > cd "C:\Program Files (x86)\SEGGER\JLink"
  > JLink.exe -speed auto -device 'MK64FN1M0xxx12' -if SWD
  

  
  
  
• At the JLink prompt
  
  

  J-Link> r
  J-Link> erase
  J-Link> q
  

  
  
  
• After that, it should be OK to use MCUXpresso

ADS1115 ADC

ADS1115 is a precision, low power, 16 bit 860 SPS I2C analog to digital converter (ADC). It has internal reference, oscillator, and programmable comparator. ADS1115 modules are readily available at online markets like AliExpress and Adafruit

Figure 1. ADS1115 Adafruit module
( learn.adafruit.com/adafruit-4-channel-adc-breakouts/downloads).

Working with JSON in C++

In this article, using JsonCpp library and wxJson library to work with JSON (JavaScript Object Notation) in C++ is discussed.

• JsonCpp
• wxJson

JsonCpp

A convenient way to use JsonCpp is adding its amalgamated source. At first, get the source from the official repository,

https://github.com/open-source-parsers/jsoncpp,

by entering the following command.

$ git clone https://github.com/open-source-parsers/jsoncpp.git