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Topic: Arduino mega 2560 crystal oscillator (Read 2 times) previous topic - next topic

shiu748

Hello

Does anyone know what is the tolerance of the crystal oscillator used in Arduino mega 2560.

Regards

retrolefty

Pet peeve

Quote

it shows the
following part, being a resonator and not a crystal,


There are ceramic resonators and there are crystal resonators, both can be called resonators. And in fact a ceramic resonator could be called a crystal resonator as it's ceramic structure is of a crystalline nature. A quartz crystal resonator also has (of course) a crystalline structure, and is what most people mean when they say, in overly shorthand fashion, 'crystal'.

Been working with crystal resonators sense the 60s where we would sometimes grind the blanks in tooth paste to try and raise it's frequency resonance, or draw with pencil lead to try and lower the frequency. Novice ham operators in the 60s were required to be crystal resonator controlled on their 75 watt maximum morse code transmitters, and not until one upgraded their licence were they free to use a VFO and were therefore no longer 'rock bound'.

Lefty

shiu748

Yes, I assume a resonator is used on the one I am using as I have taken one micro controller  as the ref and measured the skew and its gives me ppm error of upto 1000ppm.

I was trying to study the relation between the applied voltage and crystal skew. But it seems the board has resonator which is not very accurate. How can I solve this problem. My aim was to obtain less than 5ppm error with the arduino without using any external clock.

shiu748

The crystal has the following marking: SPK16.000G

shiu748

Found out from Arduino that Ceramic Resonators have been used on Arduino Mega 2560 R3.

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