Wow! That is tremendously stupid. You would think you were sending gps coordinates to a nuclear missile, not turning a light on and off.
I've seen some strange protocols/cksum calcs in my day, and this one ranks up with the **best**.
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--- In Crestron@..., "josephporter2020" <ttbtssav@...> wrote:
Might not be this, but here's a device I recently came across that used the same scheme.
--- In Crestron@..., "stainbow1" <stainbow1@> wrote:
what was the device?
Stephen D.
--- In Crestron@..., "Chip" <cfm@> wrote:
That would be an intriguing challenge... :)
I only need five short commands - I calculated the checksums by hand...
- Chip
--- In Crestron@..., Geoffrey Reynolds <greynlds@> wrote:
LOL - no SIMPL+ allowed for this :).
On Thu, Apr 19, 2012 at 1:30 PM, Chip <cfm@> wrote:
**
Okay, so requiring a checksum on a 232 string is redonkulous (these days)
to begin with - but check THIS one out:
<paraphrased>
"Two-byte checksum. Calculate an XOR of every ODD byte in the message (b1
XOR b3 XOR b5, etc) and invert the result - this is your first checksum
byte. Now calculate an XOR of every EVEN byte in the message (b2 XOR b4 XOR
b6, etc) and invert the result to obtain the second checksum byte"
Really? Really?!?!
- Chip
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