Is the Internal RC oscillator good enough for serial in and out ?

lawlopez

I'm planning on using the internal 4 MHz RC oscillator in the
SX-28.

The RC oscillator will be trimmed and it is expected that
both ends will be more or less at the same temperature.

I was wondering if the oscillator frequenct will be close enough so that
the serial data will be reliable.

I'm planning on using the compiled Basic serial in/out commands.
Both sides will be SX28AC's at more or less the same temperature
but perhaps not the same supply voltage.

There are other more sophisticated designs that I could pursue
and that would not be a problem but I'm just wondering if it will
work properly out of the box.

Do you think I should just use a crystal oscillator or resonator
and circumvent the possible problem ?

Bean

The internal 4MHz is NOT accurate enough for reliable serial comm.

Use the parallax 4mhz resonator and you won't have any problems.

Bean.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"SX-Video·Module" Now available from Parallax for only $28.95

http://www.parallax.com/detail.asp?product_id=30012
Product web site: www.sxvm.com
Available now... SX-Video OSD module $59.95 www.sxvm.com

"I'm a man, but I can change, if I have to, I guess"
Red Green
·

william chan

Well, I have tried....
If your baud rate is 600bps or below, no problem. At 1200bps some chips may need to be "calibrated" using a scope.

lawlopez

Ok, I've ordered the resonators.

I don't want to try going up hill.

I know I can do it by recovering a clock but
I also know I don't want to spend the time
bothering with that right now.

I've got other fish to fry.