Part: CubeSense V3
Doc: User Manual
Ver:
1.11
Page: 10
contents that were stored in that position. It is the user’s responsibility to choose the correct
part of the SRAM to write to and to avoid overwriting data that should be stored for use at a
later stage.
3.3
Doing detection
Even though CubeSense has the capability to capture and download images, the main
application of the module is to do Sun or Nadir detection. While doing detection the user is
not required to download or manage images. When a detection command is received by
CubeSense, the module automatically captures a new image as soon as possible, executes the
applicable type of detection on that image, and saves the result in memory. There are two
ways of issuing a detection command:
1.
Send TC 20 for a Capture and Detect:
TC 20 should be sent without any parameters
2.
Request TLM 22 for the last detection result, and automatically trigger new
capture and detection:
When requesting the latest detection result through these TLMs, a new detection is
automatically scheduled. This is the method of operating CubeSense that requires
the least communications, and is the recommended method of operating the
module.
The result of a detection can be read by either reading the result of the previous detection
that was done (TLM 20) or reading the result while also scheduling a new detection (TLM 22)
as discussed above. All of these telemetries have the following structure:
Table 4
–
Auto-trigger TLMs
Telemetry frame ID
20 and 22
Name
Detection result & Trigger
Frame length
(bytes)
6
Channels
Byte
No
Length
(bytes)
Channel
Data type Detail
0
2
𝛼
Signed
16-bit
𝛼
angle in centi-degrees
(range = -100 to 100 degrees)
2
2
𝛽
Signed
16-bit
𝛽
angle in centi-degrees
(range = -100 to 100 degrees)
4
1
Capture
Result
Unsigned
8-bit
0 = start-up
1 = capture pending
2 = successfully captured
4 = camera timeout
