ATTiny85 at 1MHz

Hi everyone,

I recently started building a wind and rain data logger. However my current solution consumed 20 mA. After some research I decided to use a ATTiny85 at 1MHz as a slave which would collect the data at really low power consumption, like this project:

However, I only find ATTiny85 chips at 10Mhz and 20Mhz at online stores. I can't find anywhere a ATTiny85 @1MHz. Am I doing something wrong? Do I have to buy a 20Mhz chip and somehow turn the speed down to 1Mhz?

I am new to the electronics world, so this maybe a really dumb question and I'm sorry if it is but I have to ask it.

Thanks in advance.

That's the maximum speed, can run off internal oscillator at 1mhz (default), 8, or 16 off the pll, or other speed up to maximum off crystal or external clock. Note that maximum speed depends on voltage. There s a graph in the datasheet.

Thanks DrAzzy. Does minimum speed depend on voltage? I want to power it from a 3.3V port and I want it to run at 1Mhz. Is this ok? Also how can I change the speed? Thanks again.

If using arduino ide, select desired clock speed from board section of tools menu, connect ISP programmer and do tools → burn bootloader. This sets the “fuses” that control clock speed.

There s no minimum clock speed.

AT Tiny85 at 1 MHz works fine down to slightly less than 2 volts.

Guaranteed to work down to 1.8V if it's the ATtiny85V. :slight_smile:

(Which is conveniently about the point where two AA batteries are dead.)