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user72028
user72028
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I have build simple Arduino ISP programmer, which works fine on ATmega 328 chips (when I select Arduino UNO board) and a ton of others (tiny45, tiny2313). But, when I want to program an ATmega8 chip, it writes it succesfuly, but then the chip runs at 1/16 of the desired speed! (for example a delay(1000) in code takes 16 seconds real-life). I have a 16 MHz crystal oscillator with capacitors connected to the chip, so I thought that the problem is not there but... when I remove the crystal, the chip still runs the same, it still takes 16 seconds. So I assume two possibilities:

  1. the crystal is somehow broken, so the chip runs from some internal thing? But I tried multiple crystals, all the same,

OR

  1. I am doing something wrong, but I really don't know what...

Does somebody have an idea what may be wrong or how to test it? Or feel free for more details...Thanks EDIT

EDIT: In IDE, I am selecting "Arduino NG or older" and then I select ATmega8 as processor. I am uploading the sketches directly, without bootloader.

I have build simple Arduino ISP programmer, which works fine on ATmega 328 chips (when I select Arduino UNO board) and a ton of others (tiny45, tiny2313). But, when I want to program an ATmega8 chip, it writes it succesfuly, but then the chip runs at 1/16 of the desired speed! (for example a delay(1000) in code takes 16 seconds real-life). I have a 16 MHz crystal oscillator with capacitors connected to the chip, so I thought that the problem is not there but... when I remove the crystal, the chip still runs the same, it still takes 16 seconds. So I assume two possibilities:

  1. the crystal is somehow broken, so the chip runs from some internal thing? But I tried multiple crystals, all the same,

OR

  1. I am doing something wrong, but I really don't know what...

Does somebody have an idea what may be wrong or how to test it? Or feel free for more details...Thanks EDIT: In IDE, I am selecting "Arduino NG or older" and then I select ATmega8 as processor. I am uploading the sketches directly, without bootloader.

I have build simple Arduino ISP programmer, which works fine on ATmega 328 chips (when I select Arduino UNO board) and a ton of others (tiny45, tiny2313). But, when I want to program an ATmega8 chip, it writes it succesfuly, but then the chip runs at 1/16 of the desired speed! (for example a delay(1000) in code takes 16 seconds real-life). I have a 16 MHz crystal oscillator with capacitors connected to the chip, so I thought that the problem is not there but... when I remove the crystal, the chip still runs the same, it still takes 16 seconds. So I assume two possibilities:

  1. the crystal is somehow broken, so the chip runs from some internal thing? But I tried multiple crystals, all the same,

OR

  1. I am doing something wrong, but I really don't know what...

Does somebody have an idea what may be wrong or how to test it? Or feel free for more details...Thanks

EDIT: In IDE, I am selecting "Arduino NG or older" and then I select ATmega8 as processor. I am uploading the sketches directly, without bootloader.

Source Link
user72028
user72028
  • 25
  • 7

ATmega 8 wrong timing with Arduino NG bootloader

I have build simple Arduino ISP programmer, which works fine on ATmega 328 chips (when I select Arduino UNO board) and a ton of others (tiny45, tiny2313). But, when I want to program an ATmega8 chip, it writes it succesfuly, but then the chip runs at 1/16 of the desired speed! (for example a delay(1000) in code takes 16 seconds real-life). I have a 16 MHz crystal oscillator with capacitors connected to the chip, so I thought that the problem is not there but... when I remove the crystal, the chip still runs the same, it still takes 16 seconds. So I assume two possibilities:

  1. the crystal is somehow broken, so the chip runs from some internal thing? But I tried multiple crystals, all the same,

OR

  1. I am doing something wrong, but I really don't know what...

Does somebody have an idea what may be wrong or how to test it? Or feel free for more details...Thanks EDIT: In IDE, I am selecting "Arduino NG or older" and then I select ATmega8 as processor. I am uploading the sketches directly, without bootloader.