An Atmel developer works with Atmel Corporation's microcontrollers, specifically AVR and ARM microcontrollers, to design and develop embedded systems. They write, debug, and test software code, primarily in C or C++, ensuring the smooth operation of these systems. Their tasks also involve creating hardware designs and schematics, and they often work on interfacing with peripherals and sensors. They utilize Atmel Studio for code development and debugging. They are also responsible for documentation, ensuring the code and systems can be understood and maintained by others. Their work contributes to various industries, including automotive, aerospace, and consumer electronics.