The Emerald "spS" data block
Rough and ready notes on the "spS" Emerald data block. Please let me know if you have any further information.
Sent at ~ 3 Hz. Only seems to be sent when the engine is running.
Characters (spaces are for readability only; they are not in the data)
|
Meaning
|
| SOH (ASCII 0x01) |
Start of header. |
| spS |
Identifies the type of block. |
| RS (ASCII 0x1E) 0
aacc |
Record 0.
These are both resistance rather than voltage readings, and hence are the opposite way to what you might expect.
aa: air temperature. Number gets smaller as the air gets hotter.
cc: coolant temperature. Number gets smaller as the coolant heats up.
cc typically starts few degrees lower (numerically higher) than aa.
Need to correlate with Emerald logging to determine the mapping between value / temperature. |
| RS 1 pppp |
pppp: barometric pressure. Not sure of the units. Always 0x4018, possibly because I don't have a MAP sensor? |
| RS 2 aaaa |
aaaa: Aux 1 input? Typically 0001, 0005. |
| RS 3 aaaa |
aaaa: Aux 2. Always 0x03FF, because not connected? |
RS 4 aabb
|
I think it's aabb, e.g. changes from 9442 to 9342. |
| RS 5 .... |
e.g. 001A, 0019, FFFF, 0000. |
| RS 6 .... |
Typically 0000 / 00FF. |
| RS 7 .... |
|
| RS 8 .... |
Always? 0000. |
| RS 9 .... |
Typically 0001 / 0005. |
| RS a .... |
Always? 0200 |
| RS b .... |
Always? 4802. |
| RS c .... |
Always? 0000. |
| RS d .... |
Always? 0000. |
| RS e .... |
Always? 400A. |
| RS f .... |
Always? 0000. |
| RS g .. |
Always? 10. |
| RS h .. |
Always? 3D. |
| RS i rrrr |
??? rrrr: Maximum ever revs. Appears to be the same as block "StS" i rrrr.
Always? 1D20. |
| EOT (ASCII 0x04) |
End of transmission. |
| SPe |
Indicates the end of this block. |
Back to the Emerald serial data format page.
This page is http://www.strangely.org/emerald/sp.html. It was first published on Thursday 2 December, 2004 and last updated on Thursday 2 December, 2004.
