Tag Archives: USB

Atmega32u4 Breakout Board Tutorial


adafruit.com has published a new tutorial for their Atmega32u4 breakout board. It discuss on how to use it with AVRdude and how to setup and use it with Arduino IDE.

We like the AVR 8-bit family and were excited to see Atmel upgrade the series with a USB core. Having USB built in allows the chip to act like any USB device. For example, we can program the chip to ‘pretend’ it’s a USB joystick, or a keyboard, or a flash drive! Another nice bonus of having USB built in is that instead of having an FTDI chip or cable (like an Arduino), we can emulate the serial port directly in the chip. This costs some Flash space and RAM space but that’s the trade-off.

Atmega32u4 Breakout Board Tutorial – [Link]

DIY Bare Minimum Arduino Mega 2560


MichaelC349 @ instructables.com has designed an Arduino Mega 2560 board with bare minimum components and small size. The resulting board is bootloaded using an Arduino UNO and an external USB to serial adapter is used to program it.

Personally to be used for robotics projects that require ATmega2560’s 256 KB flash and digital/analog pins, where the size, weight, and USB port location of the original design is not ideal.

DIY Bare Minimum Arduino Mega 2560 – [Link]

MIDI to USB Adapter with Teensy


Joonas Pihlajamaa wanted to connect his keyboard to his Macbook and for that reason he build a MIDI to USB interface using Teensy board, an optocoupler and some resistors.

Thankfully, I had a MIDI connector and a high-speed optocoupler at hand, and with these I could implement a MIDI in rather easily. After some investigation with Arduino Uno, it seemed quite simple to receive the serial MIDI bytes and dump them over Arduino serial

MIDI to USB Adapter with Teensy – [Link]

Smart Watch


Matthew Filipek from Cornell Univercity has build a nice smart watch with 1.7 inch touch screen, SD card, Bluetooth module and various apps.

One of the main inspirations for this project was Jared Sanson’s implementation of a DIY smartwatch (REF 0). With several design iterations, he was able to produce a watch in a very small package that can communicate with a PC via USB HID, features an OLED display, and has support for an accelerometer. As my project was to be completed in the span of a mere month, several of the components I got were purchased for their ease of use rather than their compactness.

Smart Watch – [Link]

Isolated USB-to-UART converter


Jacob Beningo shows how to build an isolated USB to UART converter using Sparkfun’s modules.

A simple isolation circuit that costs only a few dollars could have been used to protect the USB port on the computer. Embedded system developers get used to plugging strange hardware and components into their computers on a daily basis and rarely consider the consequences of what their actions might bring.

Isolated USB-to-UART converter – [Link]

Adding a USB power port to a switch for IoT


Jesus Echavarria @ jechavarria.com has tipped us with his latest project. In this project he adds a USB power port to a switch.

Also I need a power supply for the Arduino board, and I think that, better than a external USB AC wall adaptor or power supply, is modify the switch to add it a USB power port that can power the Arduino board. I’ve got at home a TP-Link TL-SF1008D, a simple 8 port 10/100 Mbps switch. So, let’s go to open it and add it the USB port!

Adding a USB power port to a switch for IoT – [Link]

Raspberry Pi Zero 4 Port USB Hub


Peter van der Walt has designed a nice USB Hub for Raspberry Pi Zero computer. Design files are available on github:

In line with my other projects I need to make a USB hub attachment for the Pi Zero.
Seeing as the community figured out that the Raspberry Pi Design team was clever enough to leave us D+ and D- test points at the bottom, I came up with this design above.

Raspberry Pi Zero 4 Port USB Hub – [Link]

NerO – An Energy Efficient Arduino UNO Compatible Design


A reference design for an Arduino UNO compatible board based on the FTDI FT231X USB UART, delivers 5V at a full 1A without overheating.

The UNO R3 is the staple of most Arduino based projects but it’s been around for a number of years and many of the features have been improved for example by Adafruit and Sparkfun who make excellent enhanced UNO compatibles. However, our additional requirements for a full 1A current without excess heat dissipation and FCC/CE conformity led us to consider a new 3rd party UNO compatible reference design that met these requirements hence the inspiration behind NerO

NerO – An Energy Efficient Arduino UNO Compatible Design – [Link]

Microcontrollers with USB interface are common, but…


FTDI.FT-X series USB to serial bridges can be still reasonable option even for today.

Microcontrollers with USB interface are common nowadays. Manufacturers provide source codes for USB device classes like CDC, HID, Mass storage and DFU. . Even in this case, programming USB communications may not be a trivial task. If it is only required to replace RS232 serial interface to USB, is worth considering using of FTDI TF-X series USB to serial bridge.Advantages:

  • Entire USB protocol handled on the chip. No USB specific firmware programming required.
  • Detection of connection to DCP (Dedicated Charging Port) USB port.
  • Lower requirements for microcontroller resources. Communication through UART, I2C or SPI is less resource demanding than implementation of USB CDC device class
  • Drivers for Windows, Mac OS-X, Linux and Android for free.
  • Microcontroller pins are connected to USB connector through USB/serial bridge. ESD or overvoltage spikes on USB bus can damage bridge instead of microcontroller. Replacement of small bridge chip is simpler than replacement of microcontroller.


  • USB/serial bridge chip requires PCB space and increases cost.

The X-chip brochure and X-chips overview. will provide you more information. Majority of FT-X series chips can be found in our standard stock offer

Microcontrollers with USB interface are common, but… – [Link]