LPC-Xpresso Board

The LPC812 is an ARM Cortex M0 by NXP Semiconductor which boast of 16K of flash and 4k of Ram at 30 MHz clock rate. This project is actually a breakout board for the NXP LPC812M101JPH20 microcontroller and has on board push buttons for reset and activating the boot loader. Since the project is hosted on Github, it has all the code, necessary libraries and even the Eagle library of different components along with the PCB design available, so that you can start from scratch and get the controller to work by making the circuit all by yourself.


The board has an integrated 500mA 3.3V LDO to supply both the MCU and connected devices from the USB port. The device can be programmed while using the internal bootloader and on your computer a popularly known software called Flash Magic which is easily available to download. More over the development environment for the above mentioned microprocessor is also available to download.

eLua code editor runs on ARM

If you are not familiar with eLua you should take a look at eLuaproject.net. Simply speaking eLua is an embedded program running inside microcontroller which is capable to run code written in Lua language. This is simple programming/scripting language which is fast and lightweight. It doesn’t need any operating system rather it’s a bare-metal software. So it runs fast, takes small amount of RAM.

So this is a nice candidate for embedded projects. Some time ago Karl has shown mbed platform running eLua. It proved it’s efficiency. The only annoying thing in running Lua programs, that in order to edit or create new program, they had to be loaded from PC in to SD and then run.


Eventually he started to look for faster options and decided to write a simple editor which would run in microcontroller itself. He wrote editor in same Lua language which is about 440 lines of code. Editor is capable to perform many basic operations like scroll, delete, insert, copy, cut paste and finally execute the code. Editor runs through terminal screen where programs can be edited and run on the fly.

Open source Programmable Logic Controller

You maybe heard about PLC (Programmable Logic Controllers). They are usually common in industry where automation of processes is needed. PLCs are expensive and probably hardly affordable to hobby level enthusiasts. They normally come with software packages where you can build control processes using building blocks like Lego. Want one? Well nobody told told that you cannot build one.

Take a look at open source PLC project that tries to make these things accessible for everyone. It is based on AT91SAM7S256 microcontroller with 256kB of Flash, 64kB of SRAM and 8kB of EEPROM. PLCs are usually pretty same microcontroller boards with “hardened” I/Os. First of all PLC is designed to be powered from 24V DC (optionally can be configured from 12V). it has 10 digital inputs with LED indicators. 8 outputs are paired with NPN transistors in open-collector configuration capable of sinking 200mA each. And four 10-bit analog inputs rated at 10V. The PLC controller is split in to several boards for better assembly and maintenance. There is a separate CPU board that carries MCU, communication interfaces like RS232, RS485, also RTC and EEPROM. Another is I/O board where you can find optically isolated inputs and outputs, power supply, USB and JTAG. And last one is status board with LEDs that is visible to user. The only difference from industrial PLCs that it doesn’t come with fancy GUI based builder, but rather with open source GCC tools. The PLC we reviewed is relatively small. If you are looking for bigger, there is another almost twice bigger PCL which is build using same idea.

Netduino based automatic weather station

zmashiah always wanted to have a nice weather station that would hang on the wall and display current weather and forecast. So he started a netduino based project with all features he wanted. As you may know netduino arduino shaped powerful board that houses AT91SAM7X512 ARM microcontroller and can be programmed using C#. It already has a 100mbps ethernet and microSD socket.

He attached a graphical display to indicate all data including time, date, current weather info. It connects to Weather underground to pull information. It automatically detects location, daylights savings. Weather forecast includes next 3 days where you can see high and low temperatures, humidity and wind. Iconized display makes it look really professional.