clock problem

lackofcolour

hi there,

i've managed to get my program running fine using the sx-key test board, but when i program the chip on my prototype board the sx28 doesn't seem to be running. i've checked the pin diagrams and it seems to be wired correctly. am i supposed to be using an external oscillator?

thanks

Guenther Daubach

Hi lackofcolor (or should I say "lackofclock"),

When running/testing a program with the SX-Key, the SX-Key supplies the clock to the SX chip, according to the FREQ directive in your program.

Please note: This directive only "tells" the SX-Key, which clock it shall provide while the SX is under its control. This does not specify how the SX will be clocked in a stand-alone, i.e. "SX-Key-less" environment.

In order to supply a clock to a "stand-alone" SX, you have the following options:

- Use the SX-internal clock, not very precise, about 4 Mhz max, or less, depending on the prescaler setting (use the DEVICE OSC4MHZ directive to activate it).
- Use an external clock device, either an RC circuit, a resonator, a crystal, or an external clock generator (output fed into the OSC1-pin).

You can find more information about the various clock modes in the SX-Key manual.

When testing the application with the SX-Key, make sure that the FREQ directive in the code matches the clock frequency you are later going to use in the "stand-alone" system.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Greetings from Germany,

G

lackofcolour

Thanks!