Tag Archives: USB

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]

4chord MIDI Plays All the Hits

4chord MIDI – the USB MIDI keyboard to play every major hit pop song with four little buttons. by Sven Gregori:

4chord MIDI – the USB MIDI keyboard dedicated to play all the four chord songs, from Adele via Green Day and Red Hot Chilli Peppers to U2 and Weezer. Thanks to MIDI, you can be any instrument – and all of them at once. Yay!

4chord MIDI Plays All the Hits – [Link]

LimeSDR Mini – Software-defined-radio card

An open, full-duplex, USB stick radio for femtocells and more.

The LimeSDR and LimeSDR Mini are members of the same family of software-defined radios. One does not replace the other. Rather, they are complementary.

Simply put, the LimeSDR Mini is a smaller, less expensive version of the original LimeSDR. However, it still packs a punch – at its core, the LimeSDR Mini uses the same LMS7002M radio transceiver as its big sibling. The Mini has two channels instead of four, and, by popular demand, SMA connectors instead of micro U.FL connectors. Check out the comparison table below for more details.

LimeSDR Mini – Software-defined-radio card – [Link]

White Paper: Cut the Cord with Power over Ethernet (PoE)

Providing AC power to each device individually is an extra cost especially for organizations when installing IP cameras, VoIP phones or network access switches and routers in the facilities. To help in this way some modern protocols, like USB and Ethernet, provide the power over the same data cable. However, USB is not designed for networking and long distance network applications. Besides that, the 900 mA at 5V in USB 3.0 is suitable for low-power devices like external hard disks but can’t provide enough power for high-power devices like switches and other network instruments. For these reasons, PoE (Power over Ethernet) can be the best choice.

CAT-5/5e twisted-pair Ethernet cable. Image courtesy of: CableOrganizer

PoE can provide power up to 30W beside data connectivity on any standard CAT-5/5e twisted-pair Ethernet cable, and supports 10Base-T, 100Base-T, 100Base-TX, and 1000Base-T Gigabit Ethernet interfaces.

The LEX Computech 3I390NX Series

As an example of an SCB (Single Computer Board) that provides PoE on its ports is a board called 3I390NX from LEX COMPUTECH which is based on the latest Intel Pentium Processor N4200/ N3350/E3950 Apollo Lake processor family. The Ethernet ports are provided by the Intel Ethernet controller i1211-AT.

3I390NX SCB features are:

  • Intel Apollo Lake N4200/N3350/E3950 CPU/chipset.
  • On Board 4GB DDR3L.
  • Display: HDMI, DP, VGA & eDP.
  • 5 x GbE (4 x PoE) LAN.
  • 2 x Mini PCIe.
  • 6 x USB.
  • HD Audio.
  • 2 x COM (1 x RS232 / 422 / 485 port (external), 1 x RS232 / 422 / 485 port (internal)).
  • Hardware digital Input & Output, 8 x DI / 8 x DO.

To know more about this SCB you can preview the full white paper published on IEEE Spectrum, or download it directly from here.

FT234XD – USB to BASIC UART IC

The FT234XD is a USB to serial UART interface with optimised packaging (3mm x 3mm 12 pin DFN) for smaller PCB designs and the following advanced features. Check datasheet on the link below.
FT234XD – USB to BASIC UART IC – [Link]

PD Buddy Sink – USB Power Delivery for everyone

Clayton G. Hobbs @ hackaday.io published some details of his project, a USB power delivery board. He writes:

USB Power Delivery is a cool standard for getting lots of power—up to 100 W—from a USB Type-C port. Being an open standard for supplying enough power to charge phones, laptops, and just about anything else under the sun, USB PD is poised to greatly reduce the amount of e-waste produced worldwide from obsolete proprietary chargers. Unfortunately, like all USB standards, it’s quite complex, putting it out of reach of the average electronics hobbyist.

PD Buddy Sink – USB Power Delivery for everyone – [Link]

Opendime v2 – Genuine Verified Bitcoin Credit Stick

Opendime announced their USB stick that allows you to spend Bitcoin like a dollar bill:

Opendime is a small USB stick that allows you to spend Bitcoin like a dollar bill. Pass it along multiple times. Connect to any USB to check balance. Unseal anytime to spend online.

Hopefully everyone who needed an Opendime for Christmas has got it under the tree already, because we are now out of stock! But the big news is we’ve redesigned the hardware and improved it. Same price, same concept, but some useful improvements.

Opendime v2 – Now Genuine Verified Bitcoin Credit Stick – [Link]