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Topic: Crystal reliability (Read 1 time) previous topic - next topic

krupski

Why not 3 AA batteries ?

The cheapest crystals on Arduino clones are bad quality. They might break when an Arduino board is dropped on concrete. They stop working below 0 °C. If you put many Arduino boards in the freezer, all the cheap ones will stop working.

When the voltage is low, they probably will keep on working. The circuit inside the ATmega for the crystal can be set to normal and "full swing". The normal mode should be good enough.
Since they are encapsulated in a metal box, I think that RF noise is not a problem for the crystal.
Arduino boards (real ones and clones) use RESONATORS, not crystals. In fact the first three things I do to a new Arduino board are:

  • Replace the resonator with an SMD crystal.
  • Burn a new bootloader (my own code without all the junk that the stock one has).
  • Set the LFUSE to run the crystal full swing instead of low power mode (solves all the flakey oscillator problems).
Gentlemen may prefer Blondes, but Real Men prefer Redheads!

krupski

#16
Mar 03, 2018, 03:51 am Last Edit: Mar 03, 2018, 03:51 am by krupski
The nRF was put to power down (with oscillator stopped) and then restarted again so it restarted even this cold. In there freezer is more cold than outside in winter. I did only short test to not stress the circuit (batteries mostly) more than needed. It may not prove anything but I hope it means there is a good chance it will work. I will put it in real life conditions and see results. Thank you for inputs.
Try the Energizer Lithium cells. They have a new cell voltage of around 1.8 volts, they weigh 1/2 as much as alkalines, they last a good 5 times longer than alkalines, cold doesn't bother them one bit and they have a 20 year shelf life.

Once you try them, you'll never buy alkaline again.

Gentlemen may prefer Blondes, but Real Men prefer Redheads!

ChrisTenone

Well, they also cost a dozen times what alkalines do.
What, I need to say something else too?

Koepel

"Energizer Ultimate Lithium", I use those as well for some projects.
I pay 6 euros for 4 AA, or 13.50 euros for 10.

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