by simplicio @ instructables.com:
PUB! is a Programmable USB Button on which you can program a sequence of keystrokes. When you press the button those keystrokes are “replayed” over a USB connection.
The button (which is really a rotary encoder with a built-in push button switch) is programmed using an innovative and slightly quirky interface that does not require any custom software to be installed on your computer. All you need is a text editor like Notepad (for Windows) or gedit (for Linux).
PUB! Programmable USB Button - [Link]
If you have old USB headphones you can easily transform them to a USB sound. This card can be helpful during testing of home built devices connected to the speaker or microphone ports on the PC (for example A proof of concept of a simple sonar and Constructing a homemade microphone).
USB sound card made from a broken USB headphones - [Link]
by mjlorton @ youtube.com:
I take a look at the YZXstudio USB 3.0 Power Monitor with OLED display which is sold by Franky – http://stores.ebay.com/99centhobbies
I demonstrate this very handy tool on a UBS power bank and show the issues with the USB voltage and losses across a USB cable.
USB 3.0 Power Monitor – YZXstudio - [Link]
by Solarcycle @ instructables.com:
Power Stacker is a portable, modular, USB rechargeable lithium-ion battery pack. Stack them together for power hungry projects or separate them for smaller projects with this modular system. The Gerber, BOM, and .STL files are available below.
Power Stacker does what other USB rechargeable batteries have failed to do, and that’s the ability to combine together for increased battery capacity or separate in to many small batteries for smaller projects. You can literally use the same Power Stacker batteries for many years across many applications!
Stackable USB Rechargeable Battery System - [Link]
Hey, sorry everyone, I know it’s been a while. But I hope this post will make up for that! Anyone who has done embedded programming knows that an easy way for microcontrollers (like arduino) to connect to a PC is through a serial connection. Unfortunately, not many computers have a serial port these days, and while are a lot of chips that will act like a usb-serial converter, they tend to be somewhere in the $3-5 range. However, I found one chip, the CH340G, that only costs 40 cents!
CH340G – alternative USB to serial IC - [Link]
Paranoia abounds! well maybe a bit – we are in a situation where we don’t trust our tools – especially our crypto tools – this project is an attempt to create a cheap open source entropy generator that’s open enough that one can verify and trust it.
We’ve based our design on an existing platform – our Cheap RF system – mostly because it’s cheap to build, we had existing hardware, and had just finished bringing up a USB stack for it
Our simple device is a USB stick, it is open source hardware, you can build your own, runs open source firmware – and you can physically open it to make sure that what’s inside is what you expect. With an external programmer you can also program it with your own firmware.
We generate ~350kbits per second of entropy packaged at ~7.8 bits/byte – if you use the entropy data at a lower it accumulates and we quickly approach 8 bits/byte.
OneRNG – Open Random number generation project - [Link]
Espruino Pico has everything you need pre-installed. It can be used from virtually any device with a USB port so you can get started in seconds.
ajoyraman posted a tutorial on how to make a DIY USB-matchbox oscilloscope, an instructable here:
In order to economize on the cost of an enclosure while still providing an aesthetic unit the Aj_Scope2 is enclosed in a large size cardboard matchbox enclosure.
The USB connection to the PC is on one end while the Audio-Jack for the signals to be monitored is on the other.
A ‘Busy’ LED is provided on one corner at the top and a ‘Reset’ switch is provided diagonally opposite.
The ‘Reset’ switch provides a restart of the micro-controller is the worst-case of hang-up. This typically occurs when the operator selects a trigger threshold which is out of limits with respect to the waveform being observed. If the Aj_Scope2 is operated correctly this switch is seldom used.
DIY USB-Oscilloscope in a matchbox - [Link]
by Naomi Price & Martin Rowe @ edn.com:
USB data-acquisition modules offer good value and ease of use, which makes them an attractive choice for manufacturing test. But before you use the modules in a manufacturing test system, you need to take steps to protect them. During manufacturing test of circuit boards or subassemblies, a defect in an assembly may result in a condition that damages a data-acquisition module.
Test Ideas: Protect USB measurement circuits - [Link]
A USB port is a great power source for charging a single cell Lithium-Ion battery. It is capable of supplying a maximum of 5.25V and 500 mA. The circuit above is a USB powered single cell Li-Ion battery charger. LM3622 is used as the controller. This special purpose IC has a precise end-of-charge control and low battery leakage current about 200nA. S1 and S2 select the low voltage detect enable/disable. The low voltage detection is handy for conditioning a deeply discharged battery with a low current stage, to prepare it for the full charge cycle.
LM3622 Li-Ion USB Battery Charger - [Link]