1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
[appendix]
== Flight Data Recording
Each flight computer logs data at 100 samples per second
during ascent and 10 samples per second during
ifdef::telemini[]
descent, except for TeleMini v1.0, which records ascent at 10 samples
per second and descent at 1 sample per second.
endif::telemini[]
ifndef::telemini[]
descent.
endif::telemini[]
Data are logged to
an on-board flash memory part, which can be partitioned into
several equal-sized blocks, one for each flight.
.Data Storage on Altus Metrum altimeters
[options="header",cols="1,1,1,1"]
|====
|Device |Bytes per Sample |Total Storage |Minutes at Full Rate
ifdef::telemetrum[]
|TeleMetrum v1.0 |8 |1MB |20
|TeleMetrum v1.1 v1.2 |8 |2MB |40
|TeleMetrum v2.0 |16 |8MB |80
endif::telemetrum[]
ifdef::telemini[]
|TeleMini v1.0 |2 |5kB |4
endif::telemini[]
ifdef::easymini[]
|EasyMini |16 |1MB |10
endif::easymini[]
ifdef::telemega[]
|TeleMega |32 |8MB |40
endif::telemega[]
ifdef::easymega[]
|EasyMega |32 |8MB |40
endif::easymega[]
|====
The on-board flash is partitioned into separate flight logs,
each of a fixed maximum size. Increase the maximum size of
each log and you reduce the number of flights that can be
stored. Decrease the size and you can store more flights.
Configuration data is also stored in the flash memory on
ifdef::telemetrum[TeleMetrum v1.x,]
ifdef::telemini[TeleMini and]
ifdef::easymini[EasyMini.]
This consumes 64kB
of flash space. This configuration space is not available
for storing flight log data.
ifdef::telemetrum,telemega,easymega[]
TeleMetrum v2.0, TeleMega and EasyMega
store configuration data in a bit of eeprom available within
the processor chip, leaving that space available in flash for
more flight data.
endif::telemetrum,telemega,easymega[]
To compute the amount of space needed for a single flight, you
can multiply the expected ascent time (in seconds) by 100
times bytes-per-sample, multiply the expected descent time (in
seconds) by 10 times the bytes per sample and add the two
together. That will slightly under-estimate the storage (in
bytes) needed for the flight.
ifdef::telemetrum[]
For instance, a TeleMetrum v2.0 flight spending
20 seconds in ascent and 150 seconds in descent will take
about (20 * 1600) + (150 * 160) = 56000 bytes of storage. You
could store dozens of these flights in the on-board flash.
endif::telemetrum[]
The default size allows for several flights on each flight
ifdef::telemini[]
computer, except for TeleMini v1.0, which
only holds data for a single flight.
endif::telemini[]
ifndef::telemini[]
computer.
endif::telemini[]
You can adjust the size.
Altus Metrum flight computers will not overwrite existing
flight data, so be sure to download flight data and erase it
from the flight computer before it fills up. The flight
computer will still successfully control the flight even if it
cannot log data, so the only thing you will lose is the data.
|
