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Atmel AVR Frequently Asked Questions

- Index -


Q: What is the Atmel AVR?

Q: Why use the Atmel AVR?

Q: How do I setup the Atmel AVR tools on my home PC?

Q: How to purchase an STK500 board for your study at SECTE?

Q: How do I get started using the Atmel AVR?


Q: What are good starting manuals to read for the Atmel AVR?

Q: Where can I seek help on using the Atmel AVR?

Q: Are there any text books for Atmel AVR?

Q: ISP mode error: How to fix the error about 1/4 clock frequency when I try to program the Flash memory?

Q: Serial connection error: How to fix the error about serial connection between STK500 board and the PC?


- Answers -


Q: What is the Atmel AVR?

A: The AVR is a microcontroller designed and distributed by the Atmel Corporation. The AVR has been chosen as a prime example for students in the School of ECTE to learn basic microcontroller principles. This is due to the comprehensive tools and assistance provided by Atmel. The University of Wollongong is associated with the Atmel University Program and as such thanks Atmel Corporation for their hardware donations.

 

Q: Why use the Atmel AVR?

A: The AVR microcontroller is an excellent example of current 8-bit microcontrollers that students may encounter during their projects at SECTE. The AVR STK500 development kit offers easy, reliable and extensive access to a number of possible AVR microcontrollers. Additionally, the free AVR Studio allows students to emulate their projects and laboratories with complete freedom and control over all aspects of programming.



Q: How do I setup the Atmel AVR tools on my home PC?


A: Please follow the instructions at the "AVR Tools" page.

Q: How to purchase an STK500 board for your study at SECTE

Students of SECTE can buy an STK500 board through our link with ATMEL distributors. Please download the purchasing form and complete the steps described in the form.


Q: How do I get started using the Atmel AVR?

A:


Q: What are good starting manuals to read for the Atmel AVR?

A: After working through the HOW-TO guides on the main mage, you will need more information about either the microcontroller or the development board. It may not be immediately obvious which of the many user manuals has the information you need.

The "AVR Documentation" page gives links to three essential documents:

  • "AVR STK500 board: User guide ": A useful reference for the STK500 board. I has information on boot-up, downloading code, using other AVR microcontrollers in other sockets, firmware upgrades, jumper settings and so on.
  • "8-bit AVR microcontroller ATmega8515: User Manual ": Useful information about the internals of the specific 8-bit microcontroller used in class laboratories. This includes information about using I/O ports, analogue comparator, interrupts, serial comms and more.
  • "Microcontroller instruction set ": Full assembler instruction set reference. Every instruction and their use, examples, addressing modes and ISA information.



Q: Where can I seek help on using the Atmel AVR?

A: If this website does not answer your question, then you are recommended to refer to the Atmel AVR website.

Alternatively, you may find relevant help at the "AVR Freaks". This is a very comprehensive forum with questions/answers from AVR users world-wide. Remeber to search the forum before you post because your questions may have been already answered.


Q: Are there any text books for the Atmel AVR?

A: Some of the text books that cover that Atmel AVR are listed below.

Q: ISP Mode Error: How to fix the error about 1/4 clock frequency when I try to program the Flash memory?

ISP Mode Error


A:


This error occurs because the ISP frequency is incorrectly set too high relative to the Clock Generator. To rectify this problem, click 'Ok' button to exit the error screen and then select the HW Settings tab in the programming interface window. Ensure that the Clock Generator is at the far right. Otherwise, slide it to the right, and click on the 'Write' button to save.

Next, Click on the Main tab, under the section Programming Mode and Target Settings click Settings. Make sure that the "ISP Freq" field is no more than 1/4 of Clock Frequency. To ensure the ISP frequency change is saved, click on Write button once you have selected an appropriate frequency.

 


Q: Serial connection error: How to fix the error about serial connection between STK500 board and the PC?

A: In some cases, a serial connection cannot be established between the STK500 board and the PC to download the hexadecimal file.

A common cause for this error is when a microcontroller program is already loaded into the AVR chip, and this program inteferes with the serial connection between the STK500 board and the PC.

To fix this error, erase the AVR chip by performing the following steps:

i. Hold down the RESET button on the STK500 board while clicking the "Connect" button in AVR Studio.

ii. Hold down the RESET button on the STK500 board and clicking the "Erase" button. This will erase the AVR chip on the STK500 board. After that, the AVR chip can be programmed as usual.

 
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