Electrical – Slow clock speed with Atmega328P AVR microcontroller on breadboard

A microcontroller isn't aware of a thing like time; it only knows clock ticks. So the controller's logic can't tell the difference between running at 16 MHz and 192 MHz: a clock tick is a clock tick, and it will do exactly the same in 10 clock ticks for both frequencies.

That means that when actual time is relevant it's up to you to make sure the number of clock ticks gets properly translated to time. Suppose you have a 1 ms timer for the 16 MHz controller. It will give you an interrupt every 16 000 clock ticks, that's once every ms. Run that same code on a 192 MHz controller and you'll still get the interrupt every 16 000 clock ticks, but now that will be 83 µs. So change the timer's value to 192 000. Do this for everything to which real time is relevant. If you don't the 9600 bps UART will run 12 times too fast, so set the prescaler to a 12 times higher value.

The ADC is a bit different. That one does know about time: the measurement capacitor will droop at the same rate whether you run at 16 MHz or at 192 MHz. Or at 1 Hz. While the controller will run (or rather: "stroll") happily at 1 Hz, for the ADC that's too slow. The datasheet will tell you the minimum frequency it needs.

1. check if your wire is corect, with no short-circuit. If it is ok, moving on
2. I assume you solder socket for chip. so disconect chip, put it in protobort in check if works like it should. If it is ok, moving on.
3. Enable internal clock 8Mhz inside in chip in divider by 8...with fuses and put your chip back to socket. If now works, you have a problem with external cryistal and capacitors. That means crystal dos not start..mybe circut capatance is grather (bad soldering) and ... check it. If do not work, somethink is wrong with your power or wrong wire.