Logger Notes
Format Types
The format type specifies the amount of storage required for the entry
and how the content should be interpreted.
| Char |
C Type |
| a |
int16_t[32] |
| b |
int8_t |
| B |
uint8_t |
| h |
int16_t |
| H |
uint16_t |
| i |
int32_t |
| I |
uint32_t |
| f |
float |
| d |
double |
| n |
char[4] |
| N |
char[16] |
| Z |
char[64] |
| L |
int32_t latitude/longitude (so -35.1332423 becomes -351332423) |
| M |
uint8_t flight mode |
| q |
int64_t |
| Q |
uint64_t |
Legacy field types - do not use. These have been replaced by using the base C type and an appropriate multiplier column entry.
| Char |
CType+Mult |
| c |
int16_t * 100 |
| C |
uint16_t * 100 |
| e |
int32_t * 100 |
| E |
uint32_t * 100 |
Units
All units here should be base units
This does mean battery capacity is here as "amp*second"
Please keep the names consistent with Tools/autotest/param_metadata/param.py:33
| Char |
Unit Abbrev. |
Description |
| '-' |
"" |
no units e.g. Pi |
| '?' |
"UNKNOWN" |
Units which haven't been worked out yet.... |
| 'A' |
"A" |
Ampere |
| 'd' |
"deg" |
of the angular variety |
| 'b' |
"B" |
bytes |
| 'k' |
"deg/s" |
degrees per second. Degrees are NOT SI |
| 'D' |
"deglatitude" |
degrees of latitude |
| 'e' |
"deg/s/s" |
degrees per second per second. Degrees are NOT SI |
| 'E' |
"rad/s" |
radians per second |
| 'G' |
"Gauss" |
Gauss is not an SI unit |
| 'h' |
"degheading" |
0.? to 359.? |
| 'i' |
"A.s" |
Ampere second |
| 'J' |
"W.s" |
Joule (Watt second) |
| 'l' |
"l" |
litres |
| 'L' |
"rad/s/s" |
radians per second per second |
| 'm' |
"m" |
metres |
| 'n' |
"m/s" |
metres per second |
| 'N' |
"N" |
Newton |
| 'o' |
"m/s/s" |
metres per second per second |
| 'O' |
"degC" |
degrees Celsius. Not SI |
| '%' |
"%" |
percent |
| 'S' |
"satellites" |
number of satellites |
| 's' |
"s" |
seconds |
| 'q' |
"rpm" |
rounds per minute. Not SI |
| 'r' |
"rad" |
radians |
| 'U' |
"deglongitude" |
degrees of longitude |
| 'u' |
"ppm" |
pulses per minute |
| 'v' |
"V" |
Volt |
| 'P' |
"Pa" |
Pascal |
| 'w' |
"Ohm" |
Ohm |
| 'Y' |
"us" |
pulse width modulation in microseconds |
| 'z' |
"Hz" |
Hertz |
| '#' |
"instance" |
(e.g.)Sensor instance number |
Multipliers
This multiplier information applies to the raw value present in the
log. Any adjustment implied by the format field (e.g. the "centi"
in "centidegrees" is IGNORED for the purposes of scaling.
Essentially "format" simply tells you the C-type, and format-type h
(int16_t) is equivalent to format-type c (int16_t*100)
tl;dr a GCS shouldn't/mustn't infer any scaling from the unit name
| Char |
Multiplier |
| '-' |
0 |
| '?' |
1 |
| '2' |
1e2 |
| '1' |
1e1 |
| '0' |
1e0 |
| 'A' |
1e-1 |
| 'B' |
1e-2 |
| 'C' |
1e-3 |
| 'D' |
1e-4 |
| 'E' |
1e-5 |
| 'F' |
1e-6 |
| 'G' |
1e-7 |
| '!' |
3.6 |
| '/' |
3600 |
Peter Barker
ed720e73c1