Magic Crystals or Enchanted Key

nick bernard

wow what a lamo subject.... eh uh

i recently purchased the SX Tech Tool Kit and was experiencing some problems with a program. i plugged the 50Mhz resonator into the proto board and generated other frequencies with the key and the sx wasnt working properly. so i tugged the resonator out of the board and swapped out the sx chip and everything seems fine now.

can i use an external resonator & the sx key at the same time?
did i do any permenant damage to anything?
or did my program fail for some other reason?

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League Bowling.... it's not a sport, it's a way of life

Jim Palmer

Hey Nick,

There can only be one frequency generator to the chip at a time on the prototyping board - the resonator or the SX key.· I have frequently plugged the SX-Key into the board with the crystal attached and did not sustain any permanent damage to the chip, the SX-Key or the resonator.

The good news is that it looks like the design of a new prototyping board is attempting to require the removal of the resonator before one is even able to plug in the SX-Key (see earlier thread).

Jim

nick bernard

thanks jim , i appreciate your prompt reply.

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League Bowling.... it's not a sport, it's a way of life

James Newton

Since this seems to be a regular problem, I'll make a suggestion...

...Could the demo boards have a small toggle switch added right between the Resonator and the SxKey port? SPDT. I believe that only the driven OSC pin would need to be switched. One way and the SxKey is running, the other way and the Resonator is in control...

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Paul Baker

I've done this on the board of my project, but this is to prevent frying my SXKey since I am using a smt oscillator. I am enthralled with the idea of an electronic switch which would sense current being drawn on the Vdd pin of the SXKey header and automatically switch OSC1 from the resonator to the SXKey. Like you, I believe leaving OSC2 connected to both the SXKey header and Resonator shouldn't be an issue. This is pretty far down on the totem pole of projects though.

Paul

mendoai

I did exactly what James Newton said,....switchs &·One way and the SxKey is running, the other way and the Resonator is in control... also added jumps in case I need 4MHz,10MHz 0r 50 MHZ..