Sorry for late reply. I tried with both SLOW_SCK on and off. But the Duemilanove bootloader never worked. I even tried the chip by putting it on a firend's Arduino NG board instead of bredboard. But it doesn't matter now, I am using the chips fine with optiboot recompiled with baudrate set to 57600bps. I'll be getting some better crystals next week, hope that will solve everything.

I would've posted a picture of the setup, but believe me or not, I don't even have a working camera for that.

Thanks for the reply.

I'm using 16 MHz Crystals, but they are cheap, and has low tolerance levels (for example, one of them can do baudrate up to 57600 but the same model another gives garbage at anything higher than 28800). And I have experience with other blink sketches but this is nothing like them. This blinks start as soon as I apply power, they are short blinks (.5s) with long gaps (1.5s) like it is trying to give the initial blinks of the bootloader but resets in the middle of the process.

Also, I'm using lfuse=0xFF, hfuse=0xDA and efuse=0x05 for Non-Optiboot, and lfuse=0xFF, hfuse=0xDE, efuse=0x05 for Optiboot.

Hi, I tried to upgrade my breadboard arduino, and ended up ordering some Atmega328-PU instead of Atmega328P-PU chips. I could burn the bootloader to them by modifying the avrdude.conf file with no problem, but the problem I'm facing is, the chips aren't working with any bootloader other than the Uno optiboot.

I've tried the bootloaders for Atmega328 versions of Duemilanove, Nano and Pro and with each of them, the Pin 13 LED just keep giving short blinks every 1.5 seconds and nothing else happens. I've read somewhere in this forum that this happened to someone who apparently overflown the memory with a sketch which changed the watchdog timer settings. He solved it by re-flashing the bootloader, but in my case, the bootloader is causing the problem.

I've tried the Uno bootloader and it works fine, or at least the Pin 13 LED doesn't blink continuously. With optiboot, it blinks fast 3 times and then stops. But still, I can't use the optiboot because my 16MHz crystals are very cheap and cannot provide the accuracy required to support UART at baudrate 115200. I've once tried by recompiling optiboot with baudrate 57600 and it worked very well.

I'm using USBasp to burn the bootloader and a USB-Serial TTL converter based on the VUSB protocol.

Thanks for any Reply.

Thanks. Going back to the breadboard now.

Thanks for the reply. So, would I need to recompile the bootloader with new F_CPU or just use the original one?

Also, I cannot order online as I live in a country where most shipping services either never reach or take ridiculously long time. I got all the caps and resistors already, only the crystal got me. But if I wait a I might be able to get correct crystals when the local stores replenish their stocks. But I don't know how long that will take.

Hi, I am a newbie to arduino and to the microcontrollers too. I am trying to build a cheap Arduino NG clone on a breadboard with atmega8, purely for educational/learning purposes. I seem to get everything right up to this point, using another Atmega8 with V-USB (http://www.obdev.at/products/vusb/index.html) for USB UART bridge, and everything else. The problem I have now is that surprisingly I can't find any 16MHz crystals on any local store.. I have 4MHz, 8MHz, 12MHz and the closest I got is marked 16.0083 MHz. So, can I somehow use the 16.0083 MHz crystal  and live with that? Can I do this with default bootloader for NG or would I have to compile one with different F_CPU value? And if I do that, would I be able to upload sketches with the UART bridge or use the UART for communicating with any PC while running the sketch?

Any help will be appreciated.