OpAmps 101

Dave at EEVBlog explains what Operational Amplifiers (OpAmps) are and how they work. The concepts of negative feedback, open loop gain, virtual grounds and opamp action. The comparator, the buffer, the inverting and non-inverting amplifiers, the differential amplifier, and the integrator circuit configurations are also explained.
Then a practical breadboard circuit to demonstrate a virtual ground and the effect of voltage rail limitations.

Source: eevblog

Arduino MIDI Library – QA round up

If you use the Arduino MIDI Library, and have found a bug or want to request a feature to be added, please do so in the GitHub issue tracker.

I’m currently rounding up the bugs, importing the old tickets from SourceForge, Twitter feed and e-mail sources, so that I can track them more efficiently, since the tracker on GitHub is really powerful and well integrated with Git.

In the next days/weeks I’ll be working on addressing most of these issues for the v4.2 release. Then v4.3 will be on its way with some changes on the settings system, which will allow for the same flexibility without the need to modify anything in the library files.

Thanks !

Logic Pirate from Dangerous Prototypes

Logic Pirate by Dangerous Prototypes

The Logic Pirate is an inexpensive yet capable open source logic analyzer. For just 30 bucks it can sample 8 channels, 256K samples per channel, at a blazing (overclocked!) 60 MILLION samples per second! It’s designed to support the SUMP logic analyzer protocol on Jawi’s open source software that works on most platforms.

Its big brother the Logic Sniffer is great, but this little one looks more appropriate for simpler sniffing of all digital things, and more portable (always appreciated for hackers on the move).

Source: Dangerous Prototypes.