OneWire Object

william chan

Hi anybody,

Why is the ReadRom command (should be $33 hex) missing from the list of constants?

This should be the most basic command after reset.

Thanks.

CON
setupCmd = 1 << 16
resetCmd = 2 << 16
writeCmd = 3 << 16
readCmd = 4 << 16
searchCmd = 5 << 16
crc8Cmd = 6 << 16

SEARCH_ROM = $F0

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william chan

I can't understand why the OneWire object needs 20Mhz clock even though it is written in assembly.
When I try to run it on 10Mhz clock, it hangs.

SX can do 1Wire with only 4Mhz.

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www.fd.com.my
www.mercedes.com.my

Post Edited (william chan) : 9/1/2008 9:28:56 AM GMT

Paul Baker

I haven't examined the driver, but it's quite possible the 20MHz requirement is due to relative infrequent access window for transfering data to/from the hub. The SX doesn't not have to contend with sharing it's memory. You can always try to translate the SX code onto the Propeller and see where that gets you.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.