Software User Manual - Argos 3D-P320
Last change: 2 February 2016
Version 0.14
© Bluetechnix 2016
Page 44 | 70
The pixel orientation of the color image sensor is identical to Figure 4-2.
4.15.1
UDP Color Sensor Stream
In use cases where a continuous color sensor stream is required, but only sporadic ToF sensor images, the
camera features a second UDP stream that is dedicated to send color sensor data only. It is compliant to the
data interface format in chapter 3.2 and hence compatible to tools and libraries provided by Bluetechnix.
The UDP color sensor stream is enabled in register
ColorStreamParams
, bit 2. The resolution, frame rate,
and data format (raw RGB565 or JPEG compressed) can also be configured with this register.
The destination for this stream can be configured independently of the ToF data stream, using the following
registers:
Use registers
Eth0UdpColorStreamIp0
,
Eth0UdpColorStreamIp1
to set the destination IP address.
Use register
Eth0UdpColorStreamPort
to set the destination UDP port.
It is recommended to use this stream in favor of the RTP Color Sensor Stream.
4.15.2
RTP Time Stamp
As defined in RFC 1889 by the IETF, each RTP packet header contains a 32-bit timestamp value. RTP uses a
clock rate of 90 kHz, i.e., this timestamp increments by 90000 each second.
The Argos 3D-P320 uses the same internal time base for this RTP timestamp and for the data stream
timestamps (which are part of the frame header, see chapter 3.2). This is required for the receiver, in order to
relate each received RTP frame and ToF frame on a time line.
Note that the resolution of both time stamps is different: Whereas the ToF data stream’s resolution is 1us
(1MHz clock), the RTP stream’s resolution is 11.1us (90kHz). To convert the RTP time stamp value to
microseconds as well, use the formula
𝑇
2𝐷
=
100 𝑇
𝑅𝑇𝑃
9
4.15.3
Color Sensor Control
The color sensor features automatic exposure and gain control (AEC/AGC) and automatic white balance
(AWB). By default, these are switched on.
These features can be controlled via register
ColorSensorControl
. Switching off AEC/AGC and/or AWB
means that the sensor freezes the current values for exposure, gain, and white balance.
In case the AEC/AGC feature is switched off, the sensor’s exposure can be controlled via register
ColorSensorExposure
, and the gain can be set in register
ColorSensorGain
. Reading from these registers
return the current values of the sensor (also in AEC/AGC on mode), or the last user-defined registers, if the
color sensor is not operating currently.