OpenOCD is great because its cross platform, open source, and has support for a vast number of chips & programmers. You can use OpenOCD with dongle-programmers such as J-Link and ST-Link or even an FTDI chip. But, if you have a spare Raspberry Pi (and who doesn't these days?) you can use it as a native OpenOCD programmer with just a few wires.
This guide will show you how to build an Arduino package tracker that will alert you when an anticipated package arrives at your door. Using an internet-connected Arduino, a proximity sensor, and Temboo, we’ll build a device that connects hardware to web services in order to track packages and notify you when they arrive.
We like the AVR 8-bit family and were excited to see Atmel upgrade the series with a USB core. Having USB built in allows the chip to act like any USB device. For example, we can program the chip to 'pretend' it's a USB joystick, or a keyboard, or a flash drive! Another nice bonus of having USB built in is that instead of having an FTDI chip or cable (like an Arduino), we can emulate the serial port directly in the chip. This costs some Flash space and RAM space but that's the trade-off.