Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: Asellith on April 14, 2009, 01:45:48 PM

Title: AVR Fuse issues (Internal/External Clocks
Post by: Asellith on April 14, 2009, 01:45:48 PM
Ok I'm a noob to AVRs and I'm trying to learn them. First thanks to Admin your tutorials are great even thought I already know other MCUs I don't get the feeling it is to low level for me.

I was changing the fuses for the clock. I changed it to External 8 mhz instead of internal. Now I can't talk to it anymore. I don't want to have to wait on this project till I can get some crystals ordered. Is there a way to change the fuse back or something? I don't have a frequency generator that goes above 200 kHz. Can I use that to at least talk to the chip?
Title: Re: AVR Fuse issues (Internal/External Clocks
Post by: GearMotion on April 14, 2009, 02:01:14 PM
Do you have something else you can steal a clock from? If you "know other MCUs" do you have a development board that is running a PIC, Freescale, 8051 -whatever- that you can steal the clock source? You could potentially use a temporary jumper from another board, or steal a crystal to clock your AVR to get the settings fixed.
Title: Re: AVR Fuse issues (Internal/External Clocks
Post by: Asellith on April 14, 2009, 02:26:17 PM
Well I forgot about the electronics lab. My department doesn't have anything but we have a fully equiped electronics lab in the building next door. So I went over there and "borrowed" a 8 Mhz crystal :) Sometimes working for a college has its perks. Now if I can convince them to give me access to the equipment over there on a regular basis.
Title: Re: AVR Fuse issues (Internal/External Clocks
Post by: Admin on May 24, 2009, 07:26:26 PM
Just for future ref, you can use another mcu or anything that can do as low as 125KHz.