USBasp is a USB in-circuit programmer specifically designed for Atmel AVR microcontrollers. It serves as a bridge between your computer and an AVR chip, allowing you to upload (program) firmware directly onto the microcontroller while it's still in its circuit, hence "in-circuit."
Understanding USBasp
At its core, USBasp provides a low-cost and straightforward way to program the popular Atmel AVR family of microcontrollers, which are found in many electronics projects including Arduino boards (though Arduino often uses its own USB interface). Its primary function is to facilitate the process of flashing compiled code onto the AVR chip's memory.
Simple Composition
The design of the USBasp is quite simple, contributing to its affordability and widespread use among hobbyists and developers. Based on its design:
- It simply consists of an ATMega88 or an ATMega8 – These are small microcontrollers from the Atmel AVR family themselves, programmed to act as the programmer.
- and a couple of passive components – These include basic electronic parts like resistors, capacitors, LEDs, etc., required for power filtering, signaling, and operation.
This minimal component count makes the device easy and inexpensive to manufacture.
USB Connectivity
A key feature highlighted in the reference is how USBasp handles the USB communication with the computer:
- The programmer uses a firmware-only USB driver. This means the microcontroller (ATMega8 or ATMega88) handles the USB protocol using just its internal processing and firmware, without requiring a dedicated, complex USB interface chip.
- Consequently, no special USB controller is needed on the USBasp board itself beyond the main microcontroller, simplifying the hardware design further.
This firmware-based approach makes the USBasp a flexible and low-cost solution for programming AVR chips via a standard USB port.
In summary, USBasp is an accessible hardware tool that enables you to program Atmel AVR microcontrollers directly through a USB connection, utilizing a simple design centered around an AVR chip and a firmware-based USB interface.
