Tag Archives: USB

Isolated USB to UART Converter for Arduino Pro Mini

Simple, tiny USB to UART converter with digital isolator working between 2.5V and 5V up to 3Mbaud, with the Arduino Pro mini connector.

It’s a USB to UART converter with a digital isolator at the UART side. It has a micro USB for connecting to the PC and a 6 pin header with the same pin-out of the Arduino Pro mini board.

The chip FT231XQ is used as interface between the USB and the UART protocol, while the Si8642 is used for isolate the board from the PC. This converter is very useful if you are working on some projects and worrying about short circuit with the main power supply. Because the isolator isolates the two sides therefore there is no electrically connection.

Specifications

  • Original FT231XQ: Compatible with almost all the operating systems and capable of variety baud rates from 300 baud up to 3 Mbaud
  • Original Si8642BB-B-IS1: Low-Power Quad-Channel Digital Isolators with isolation rating up to 2.5kV
  • Size of 40 x 17 mm
  • 4.1 mm isolation between the two sides guarantee an electrical isolation up to 1kV
  • Working between 2.5V to 5V.
  • TX and RX LEDs indicators.
  • Micro USB connector.
  • Standard 2.54mm 6 pins female header.
  • Protected by a transparent heat shrink sleeve.

The board is live on kickstarter available for funding and has 24 days to go.

The ezPixel is an Upcoming FPGA based WS2812B Controller Board

FPGAs are field programmable gate arrays which basically means they are reconfigurable hardware chips. FPGAs have found applications in different industries and engineering fields from the defence, telecommunications to automotive and several others but little application in the maker’s world. Mostly, as a result of being largely difficult and high cost as compared to the likes of Arduino, but the introduction of the ezPixel and other similar FPGA boards is making this a possibility.

Prototype modules.

The ezPixel board, by Thomas Burke of MakerLogic, is a small size FPGA based circuit board that can be used to drive up to 32 strings of WS2812Bs, for up to 9,216 LEDs in total, a very first of its kind. These WS2812B programmable color LEDs have been a phenomenon in the maker’s world, being used in various Led Lights and creating of various Light Artworks. These popular LEDs comes in strings that can be cut to any length, and only require a single wire serial data connection to control all the lights in the string individually, and multiple strings can be stacked together to create large two-dimensional displays.

ezPixel description.

Most WS2812B controller boards can be used to control up to hundreds of these LEDs, but not thousands of them. The ezPixel board is a perfect fit for applications that use thousands of these LEDs. The ezPixel board is powered by the Intel MAX FPGA, a single chip small form factor programmable logic device with full-featured FPGA capabilities, and it’s designed to interface with other Micro-controllers or any SPI/UART host device. The ezPixel board serves as bridge between microcontrollers and long WS2812B strings. A user sets the length of each string using simple commands that are sent via the SPI or USB/UART communication link.

The following below are the features of the ezPixel:

  • WS2812B Smart Pixel Controller.
  • Up to 32 Strings can be controlled independently.
  • Up to 9216 LEDs can be controlled.
  • Communication:
    • USB/UART Interface.
    • SPI Interface.
  • Read/Write Pixel Memory.
  • FPGA – Intel MAX10M08 FPGA.
  • Dimension:
    • 1” x 3” (25mm x 76mm).
  • SPI Flash.

The ezPixel can run as a standalone display controller as a result of its serial flash memory chip, and this board is slated for a crowdfunding campaign in early 2018.

USB To 12V Boost Converter

This project provides 12V output from any USB power source, like PC USB port, USB adapter or power banks. LM2577ADJ boost converter IC is the heart of the project. The IC can handle load up to 800mA, it’s advisable to use only 200mA load on output to be on the safe side. The LM2577 are monolithic integrated circuits that provide all of the power and control functions for step-up (boost), fly back, and forward converter switching regulators. The device is available in three different output voltage versions: 12V, 15V, and adjustable. Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Listed in this data sheet are a family of standard inductors and fly back transformers designed to work with these switching regulators. Included on the chip is a 3.0A NPN switch and its associated protection circuitry, consisting of current and thermal limiting, and under voltage lockout. Other features include a 52 kHz fixed-frequency oscillator that requires no external components, a soft start mode to reduce in-rush current during start-up, and current mode control for improved rejection of input voltage and output load transients.

USB To 12V Boost Converter – [Link]

Tomu – An ARM board which fits inside your USB connector

Tomu is a programmable computer that is so small that can fit entirely inside a computer’s USB port. It sticks out just a little bit, enough to allow you to press one of the two buttons on it’sy side. It also have two LED lights, to let you know what I’m up to. The project is coming soon on crowdsupply.com

Specifications

  • 25 MHz ARM Cortex M0+ CPU
  • Two LEDs
  • Two capacitive-touch buttons
  • 8 kilobytes of RAM
  • 64 kilobytes of flash
  • Full and Low Speed USB

Nevma: Gesture Control for the Masses

Nevma is a simple to build, program and utilize device that translates your hand gestures into keyboard and mouse input. Just plug it in your USB port and magically wave through your presentations, documents, pictures, songs and the like. by Dimitris Platis @ instructables.com

Working at Delphi (soon Aptiv) allows me the luxury of being immersed in a high-tech and innovative environment that provides constant inspiration for creating new and exciting gadgets. One day, some colleagues mentioned gesture control being one of the recent trends in automotive. This got me thinking of ways to bring gesture control to the broader audience in an affordable and easy to use package. And thus, Nevma was born.

Nevma: Gesture Control for the Masses – [Link]

Raspberry Pi Zero Docking Hub

Add more connectivity to your Raspberry Pi Zero with this docking hub. Available on kickstarter for 16 USD and has 34 days to go.

The Pi Zero USB Docking Hub is a stackable USB Hub that comes with 5 x USB 2.0 data and charging ports, a micro USB port for power input, an RJ45 port for Ethernet, and a 3.5mm audio input/output jack. Installation would take only seconds. Just snap your Pi Zero onto the top of the docking hub station, the four pogo pins on the hub station will connect to the signal pads on your Pi. There is no soldering required!

Raspberry Pi Zero Docking Hub – [Link]

CH340E, A New Small Serial to USB Chip

WCH, a Chinese integrated circuits manufacturer, has just released a new serial to USB chip called CH340E. Unlike other CH340 chips, it doesn’t require an external crystal and also needs less PCB space and BOM.

CH340 is a 3x3mm tiny chip comes in MSOP10 package and has 10 pins. Although it is smaller than other alternatives, it is a little more expensive than them. But considering other components and PCB size needed, the total cost of the BOM may be lower.

According to Electrodragon, it needs only two external parts to build a full function circuit. They also tested it with up to 150,000 baud rate to flash an ESP8266 chip. Most features and technical specifications are the some for CH340 family including CH340E, so the same drivers will work with it.

CH340E features

  • Full-speed USB device interface, compatible with USB V2.0.
  • Emulation standard serial port used to upgrade the original serial peripherals or add additional serial port via USB.
  • Computer applications under the Windows operating system serial port are fully compatible, without modification.
  • Hardware full duplex serial port, built-in send and receive buffer, support communication baud rate 50bps ~ 2Mbps.
  • Support common MODEM contact signal RTS, DTR, DCD, RI, DSR, CTS.
  • Through the additional level conversion device, providing RS232, RS485, RS422 and other interfaces.
  • Software compatible CH341, CH341 driver can be used directly.
  • Support 5V supply voltage and 3.3V supply voltage or even 3V supply voltage.
  • Built-in clock, no external crystal.
  • Available in SOP-16 and SSOP-20 and MSOP-10 lead – free packages, RoHS compliant.

The chip costs about 42 cents with a minimum order of 5 pieces on Eelectrodragon store. There is also an option to get a small board featuring the CH340E for about $1, and maybe cheaper in the future. Finally, the most powerful feature of this chip is that you can easily add USB connectivity to your own design.


Source: CNX-software

USB powered – PCB TeslaCoil

Daniel Eindhoven build a usb powered Teslacoil able to produce small sparks. The coil of the device is printed on the board!

A new and improved PCB spiral Teslacoil. This Teslacoil has etched windings on a print circuit board. It has a USB interface which also powers the coil. The resonance frequency is about 4MHz. It has a turns ratio of 1:160 with 6mil tracks for the secondary. The total trace length of the secondary is 25m.

USB powered – PCB TeslaCoil – [Link]

Three Ways to Make Arduino Works As A USB/TTL Converter

Even if you have years working with electronics, you will still find some simple hacks that you never thought about before. Personally and to save money, when I was a student with a very limited budget I knew that my Arduino UNO can work as a USB/TTL(serial) converter. I used to remove the Atmega328P from my Arduino UNO R3 board in order to use the board as a converter not as a development board.

Why we need to do some tweaking to Arduino in order to use 0 and 1 pins for direct USB <-> UART conversion? This is because of what’s called fan-out (fan-out of a logic gate output is the number of gate inputs it can drive). In Arduino UNO case, the RX & TX lines (pins 0 and 1) are connected to FT232RL/Atmega8U2 USB to TTL bridge and to the Atmega328P MCU (check the schematic). So using the same pins with an external connections without doing any changes to Arduino UNO board probably won’t work.

Patel Darshil over Hackster.io listed three ways to make Arduino works as a USB/TTL converter:

Hack #1: Set Pin 0&1 Mode to Input Mode

This is done using code:

Pin Mode Set Arduino

But why this solves the problem? Well, GPIO can operate in two modes, input and output. In the input mode the equivalent impedance of the pin is too high; therefore, the Arduino/Atmega328P’s pins will have almost no electrical effect to the converter RX/TX pins.

Hack #2: Keep Atmega in Reset Mode

Just connect the RES pin with GND (the bold red wire in the image bellow)

Arduino Reset
Image Courtesy of Patel Darshil

GPIOs are configured using special registers. For example, Atmega has GPIO port data direction register (DDR) to set the GPIO as an input or an output for each port. The value of this register is cleared during reset. Therefore, the MCU’s GPIOs mode will be input. This means high impedance, subsequently.

Hack #3: Remove The MCU

This is the common way used by most Arduino UNO users, but it’s not applicable when it comes to new versions of Arduino; where, the MCU is SMD and can’t be removed.

WINXI – Arduino ZERO M0 Stick

WINXI – arduino ZERO Pro M0 compatible stick, RGB led, Micro SD, AtSamD21E18. Arduino zero pro compatible board with USB programming suitable for experienced users.

WINXI – Arduino ZERO M0 Stick – [Link]