I remember that once in the beginning I said that I don’t want to buy a programmer/debugger hardware for learning a new MCU like the STM32 and also STM32s already come with built-in bootloader to facilitate programming via USART just like Arduino. Still the second is true. Well what about the first? To my own surprise I actually acquired a number of STM32-related stuffs since the time I started playing and exploring them. I actually bought both ST-Link 1 and 2 programmer-debuggers and several STM32 boards from Waveshare Electronics (http://www.wvshare.com). I believe learning new stuffs is more valuable than anything else.
STM32 Programming Tips and Tricks - [Link]
by Francois AUGER & Philippe Fretaud:
Many previous Design Ideas [1, 2] have shown how to use the Charlieplexing technique  to drive as many LEDs as possible with a minimum number of I/O lines. This Design Idea shows how you can drive three LEDs and scan three switches with only three I/O lines instead of six. Using the same principle, it will also be possible to manage four switches and two LEDs, or five LEDs and one switch. It works well with Atmel ATmega microcontrollers including the Arduino, and could be of particular interest for any eight-pin devices, or when you’ve simply run out of I/O.
3 pins, 3 LEDs, 3 buttons - [Link]
App note (PDF) on NXP’s Agile I/O expander, discussing its capabilities and how to use it efficiently.
I2C-bus GPIO devices are widely used and expand a control processor’s pins to 8-, 16- or 24- bits of general-purpose input or output. The characteristic of these I/O needs to be accurately known to efficiently use them in a system. This application note will explore the actual electrical characteristics of Agile I/O GPIO pins.
App note: Low Voltage Agile I/O GPIO Input/Output Characteristics - [Link]
Any microcontroller must have I/O pins for taking inputs and providing outputs. The ATXMega32A4U just like any other micro has 34 programmable I/O pins divided unevenly amongst six IO ports. Most I/O ports are 8 bit wide. XMega I/Os have digital, analog and special purpose functions. Some I/O pins have more than one use. A quick view of the XMega I/O pins reveals the purpose of these pins.
XMega I/O Ports - [Link]
Embedded modules may surprise you by their contribution and an overall costs savings.
As we know „embedded module“ is a quite wide term and it can represent a powerful microcomputer with OS, but it can also be a significantly simpler module with a microcontroller and peripherals, still able to add considerable functionality to a target device.
Typical representatives of useful modules, which add a lot – without big costs are so called quick start modules from company Embedded Artists. Their contribution is in a ready-made „tuned up“ PCB containing for example in case of module LPC4088 QuickStart Board (EA-QSB-016) the microcontroller itself (Cortex- M4), memory, display controller and many interfaces like Ethernet, USB, UART, SPI, CAN, PWM, Analog In/Out, I2C, XBee compatible connector and other.
Especially at low and mid-volume production batches their contribution is mainly in the fact, that it is a really proven solution with a guaranteed operating temperatures range, proper ESD protection and mainly – supported by a wide scale of development tools (free). In case of solving of problems, it´s still possible to contact customer support of company and a lot of hints for successful usage, source codes and libraries can be found directly on the producer´s website.
Try to go easier way - [Link]
OpenHardwareExG, An open source platform for ECG, EEG, EMG, ENG, and EOG signal processing:
The OpenHardwareExG is a platform for ECG, EEG, EMG, ENG, EOG, and evoked potential applications.
The OpenHardwareExG platform was originally developed as part of the eeg-mouse project.
The main goal of the project is to build a device that allows the creation of electrophysiologic signal processing applications. In addition:
Hardware and software that we develop will have a free/open source license. We also prefer to use hardware and software that are free/open source.
We would like to keep the hardware DIY compatible (hand solderable, with parts that are readily available in small quantities, etc.)
For us, this is a hobby and learning project. It’s important to keep it fun, and take the time to learn along the way.
OpenHardwareExG: An open source platform for ECG, EEG, EMG, ENG, and EOG signal processing - [Link]
Microchip Technology Inc has introduced a PIC32 Bluetooth starter kit. The kit includes a board with a PIC32 microcontroller, HCI-based Bluetooth radio, Cree high-output multi-color LED, 3 standard single-color LEDs, an analog 3-axis accelerometer, analog temperature sensor and 5 push buttons for user-defined inputs. In addition the PICkit™ On Board (PKOB) eliminates the need for an external debugger/programmer and supports USB connectivity and GPIOs for rapid development of Bluetooth Serial Port Profile (SPP), USB and general-purpose applications. To support Bluetooth audio the starter kit also includes an interface for a plug-in audio CODEC daughter card set for release at a later stage.
Microchip Bluetooth Starter Kit - [Link]
by Joel Williams @ joelw.id.au:
I bought Avnet’s $49 Spartan 3A development board but it was discontinued not long afterward – right about the time when I decided I needed a few dozen more. I’ve since done some extensive research (thanks, Google!) to find a comparable thrifty thrill.
When choosing a development board, consider what you get with it and what you want to use it for. FPGAs are ideal for use with high speed peripherals, and in general it is much easier to buy a board that contains the part you want, rather than trying to add one on later (and inevitably giving up and upgrading to a more capable board).
Cheap FPGA Development Boards – What to look for - [Link]
by TONY DICOLA @ learn.adafruit.com:
Have you heard about small Linux-based development boards like the Raspberry Pi or Beaglebone Black, but been confused about which one is best for you? This guide will compare the specifications, performance, power usage, and development experience of four popular Linux-based development boards to help you choose which is right for you!
Embedded Linux Board Comparison - [Link]
Ralph Doncaster writes:
Several months ago I noticed the Attiny88. It has several more I/O than the Atmega328, with an extra Port A and PC7. And unlike most of the other Attiny series, it has real SPI instead of USI, so libraries using SPI don’t have to be re-written. At just 86c for qty 1, it is the also the cheapest AVR with 8KB flash. Since QFP-32 parts aren’t easy to work with, I searched for breakout boards and found QFP32 to DIP32 boards that would allow me to use them in a small breadboard.
Breaking out a QFP Attiny88 AVR - [Link]