Q1: What is the Microchip Technology AT90USBKEY2?
A: The Microchip AT90USBKEY2 is a development board designed to help engineers and developers prototype and evaluate USB-based applications. It features the AT90USB1287 microcontroller, which supports USB functionality, and is ideal for creating and testing USB devices like keyboards, mice, or communication interfaces.

Q2: What microcontroller is used in the AT90USBKEY2?
A: The AT90USBKEY2 uses the AT90USB1287 microcontroller, which is a high-performance 8-bit AVR microcontroller with USB capabilities. It features a rich set of peripherals including timers, communication interfaces, and 128KB of Flash memory.

Q3: What are the key features of the AT90USB1287 microcontroller?
A: The AT90USB1287 microcontroller used in the AT90USBKEY2 has 128KB of Flash memory, 8KB of SRAM, and 4KB of EEPROM. It supports full-speed (12 Mbps) and high-speed (480 Mbps) USB communication, along with a wide range of peripheral interfaces like SPI, UART, and I2C.

Q4: What USB protocols does the AT90USBKEY2 support?
A: The AT90USBKEY2 supports both USB 2.0 full-speed (12 Mbps) and high-speed (480 Mbps) protocols. This allows it to be used for a variety of USB applications, including device, host, and OTG (On-the-Go) modes, making it versatile for USB device development.

Q5: How can the AT90USBKEY2 be programmed?
A: The AT90USBKEY2 can be programmed using the USB interface, and it supports in-circuit programming using the standard USB bootloader. The board is compatible with the Atmel Studio software suite, which provides an easy-to-use environment for code development and debugging.

Q6: What is the purpose of the USB connector on the AT90USBKEY2?
A: The USB connector on the AT90USBKEY2 is used for both power and data transfer. It allows the board to be connected to a computer or other USB host devices for programming, communication, and powering the board during development.

Q7: Can the AT90USBKEY2 be used as a USB host?
A: Yes, the AT90USBKEY2 can function as a USB host in addition to being a USB device. This allows it to interface with other USB peripherals such as mice, keyboards, or other USB devices, enabling its use in a wide range of applications.

Q8: What kind of power supply does the AT90USBKEY2 use?
A: The AT90USBKEY2 is powered via the USB connection, typically drawing 5V from the host device. It can also be powered through an external power supply if necessary, but it is primarily designed to be powered by the USB connection for ease of use.

Q9: What development tools are required for using the AT90USBKEY2?
A: To use the AT90USBKEY2, developers typically use Atmel Studio, which is a free integrated development environment (IDE) that supports programming and debugging for the AT90USB1287 microcontroller. Other tools like the AVRISP mkII or USBasp may be used for programming via the ISP interface.

Q10: What peripherals are available on the AT90USBKEY2?
A: The AT90USBKEY2 includes a variety of peripherals for development, including GPIO pins, UART, SPI, I2C interfaces, an LED indicator, push buttons, and a USB connector. These peripherals are useful for testing and prototyping a range of USB-based applications.

Q11: Can the AT90USBKEY2 be used for custom USB device development?
A: Yes, the AT90USBKEY2 is specifically designed for custom USB device development. With its support for both USB device and host functionality, developers can design and prototype USB peripherals, such as custom keyboards, USB audio devices, or USB communication interfaces.

Q12: What programming languages can be used to program the AT90USBKEY2?
A: The AT90USBKEY2 can be programmed using C or C++, as the Atmel Studio development environment provides tools for writing, compiling, and debugging code in these languages. Additionally, assembly language can be used for low-level control of the microcontroller.

Q13: Does the AT90USBKEY2 support USB HID (Human Interface Device) applications?
A: Yes, the AT90USBKEY2 supports USB HID applications. Developers can use it to create USB-based devices like keyboards, mice, and game controllers by implementing the USB HID class within the microcontroller's software.

Q14: What is the size of the AT90USBKEY2 board?
A: The AT90USBKEY2 development board is compact, with dimensions of approximately 76mm x 53mm. Its small size makes it portable and easy to integrate into prototype setups, offering convenience for testing and development in space-constrained environments.

Q15: What is the role of the LED indicator on the AT90USBKEY2?
A: The LED indicator on the AT90USBKEY2 is typically used to signal the board's status, such as indicating power-on, USB enumeration, or other operational states. It helps provide feedback to the user during the development process.

Q16: How is debugging done on the AT90USBKEY2?
A: Debugging on the AT90USBKEY2 can be done through Atmel Studio using the built-in USB bootloader or via an external debugging tool like the JTAGICE or a compatible debugger. The board supports breakpoints, step-through debugging, and variable monitoring for efficient development.

Q17: Is the AT90USBKEY2 compatible with other USB peripherals?
A: Yes, the AT90USBKEY2 is compatible with other USB peripherals when used in USB host mode. It can communicate with USB devices like mass storage devices, printers, and other USB-compliant peripherals, making it suitable for a wide range of USB-based projects.

Q18: What is the maximum clock speed of the AT90USB1287 microcontroller?
A: The AT90USB1287 microcontroller in the AT90USBKEY2 operates at a maximum clock speed of 16 MHz. This speed is sufficient for handling a variety of USB communication and control tasks, making it ideal for USB device and host applications.

Q19: Can the AT90USBKEY2 be used in USB audio applications?
A: Yes, the AT90USBKEY2 can be used in USB audio applications. It supports full-speed USB communication, which is suitable for audio data transfer, and can be programmed to implement custom USB audio devices such as USB speakers, microphones, or audio interfaces.

Q20: What is the function of the push buttons on the AT90USBKEY2?
A: The AT90USBKEY2 features push buttons that can be used as user inputs for interacting with the development board. These buttons can be programmed to trigger specific actions, such as initiating a USB communication protocol or toggling device states during development and testing.