Brian Dorey made this DIY USB to RS485 adapter, that is available at Github:
We looked for a full-duplex ready-made adapter but all the ones we found are only half duplex devices and as we needed to be able to supply 12 volts via the RJ45 connectors on the slave boards we decided to make our own USB to RS485 full duplex adapter using a USB converter chip from FTDI.
The board uses an FT230X with an RS485 converter chip which outputs to a set of header pins and also an RJ45 socket.
The new adapter board can supply power to the slave devices through the USB port or can be powered from an external supply by removing a power selector jumper. The board also has an on board 120R terminator resistor with selection jumper and LED’s to show serial activity.
USB to RS485 adapter - [Link]
Alan Parekh @ hackedgadgets.com writes:
This video was going to be a repair of this Portable USB Charger but as it turns out there wasn’t anything electrically wrong with it. It didn’t work out of the box but I think that must have been caused by some oxidation on the USB contacts. It seems to work like a champ now. The control chip for the DC/DC converter looks to be this DHMF chip. I have never seen the swoop logo before and can’t seem to find any data on this 5 pin device though. It is probably similar to the LT1302 (PDF) that the Adafruit MintyBoost uses. The efficiency of this circuit doesn’t appear to be as efficient as a proper one built using the LT1302 though since when drawing 500mA from the output it can maintain very close to 5 volts out (2.5 watts) but needs an input of 3 volt at 1.3 amps to do it (3.9 watts). This gives us an efficiency of about 64%, the graph from the datasheet of the LT1302 indicates that it could perform at about 86% under these conditions.
Portable USB Charger Teardown - [Link]
One basic need of a computer scientist is to measure the power that a USB device drains off the PC. This device is plugged between the PC and a USB device and displays the current on an LCD. For currents under 100mA it is displayd in 0.5mA steps and 1mA steps for currents over 99.5mA. It is built with an AVR programmed in assembler.
USB Power Monitor - [Link]
This project started out from a need to build a simple device for monitoring the CAN bus. I choose the NUC140LC1CN 32K Cortex-M0 microprocessor from Nuvoton for major reason – it has both USB and CAN peripherals.
CAN to USB Interface - [Link]
IViny is easy to use and USB based simple low-cost DAQ and measurement device for data acquisition application. It can be used quickly without any low level electronically knowledge.
- 2 channels 0 – 5V and 0 – 3V digital input/output
- 2 channels 0 – 5V 10 bit analog input
- Channel maximum current 20 mA
- ATTiny85 based
- USB supply, no need external supply
- V-USB based communication
- PC user interface
- 150 S/s (it will increase with future next firmware upgrade still under development)
- 50 mm x 33 mm x 17 mm
IViny Compact Data Acquisition Device - [Link]
Charge and protect your devices while blocking data syncing and “juice jacking.” For work, home, travel, everywhere!
If you charge via USB – which all smartphones and tablets do – Umbrella will protect your data. When connected to any USB port, Umbrella allows power to flow to your device so it can charge, but physically disconnects the data connections – eliminating any possible data theft or leak.
Umbrella USB - [Link]
This USB to serial converter project is easy to build, it is simple and inexpensive. It is based on the FT230XS from FTDI Chip.
USB to Serial converter using FTDI FT230X - [Link]
This USB to serial (TTL) converter project is easy to build, it is simple and inexpensive. It is based on the PL2303SA USB to USART bridge from Prolific.
USB to Serial converter using PL2303SA - [Link]
As promised we have built a transceiver USB dongle, for receiving data from various sensors like, smart meters, smoke detectors and temperature/humidity sensors. We’ll provide some code examples on how this trasciever can be used, and software for decoding data from diferent sensors enumerated above.
USB RF 433.92 MHz Transceiver module - [Link]
7-42VDC Input 5V 2A USB Output Power Supply. Compatible with Raspberry Pi, Arduino, iDevices, Mobile Phones and other USB Devices.
Having to use a Raspberry Pi and other USB Devices in an electronics production environment where 5V isn’t standard, I have noticed a lack of power supplies capable of fitting in. A unit had to be designed to fit into systems where 12V & 24V are the norm or where batteries / solar panels etc are the only supply method available.
7-42VDC to USB Supply/Charger - [Link]