Sensing Sensing

The Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information outdoors in all weather conditions, anywhere on the Earth where there is an unobstructed line of sight to six or more GPS satellites.

Erle-GPS is a GPS designed for Erle-Brain 3 that delivers a GNSS engine for GPS/QZSS and GLONASS combining high sensitivity and low power consumption. It requires the following ports: UART (GPS) and I2C (compass). These ports will power up the device.

Erle-Brain 3 camera module takes pictures at a resolution of 8 megapixels. A photo taken with the camera module will be around 2.4MB. This is about 425 photos per 1 GB.

Taking 1 photo per minute would take up 1GB in about 7 hours. This is a rate of about 144MB per hour or 3.3GB per day.

Feature Description
Still resolution 8 Megapixels
Video modes 1080p30, 720p60 and 640x480p60/90
Linux integration V4L2 driver available
C programming API OpenMAX IL and others available
Sensor Sony IMX219
Sensor resolution 3280 × 2464 pixels

To take a picture with the integrated camera on Erle-Brain 3 do the following:

erle@erle-brain-3~$sudo raspistill -o erlepic.png

Fetch the picture from outside of Erle-Brain 3 by typing:

scp erle@erle-brain-3.local:~/erlepic.png .

The camera can be a important part of your brain, not only for take photos, can be useful for FPV or remote control.

Video Streaming

Camera images are fed into ROS directly using the raspicam_node that it's automatically launched. To be able to see the images, in your Erle-Brain 3:

erle@erle-brain-3~$rosservice call /camera/start_capture

On you Desktop computer (or wherever you wish to visualize the images), and after configuring appropriately the ROS_MASTER_URI environmental variable:

# NOTE: not all distros of ROS would allow this, in some this command will return
# immediately
erle@erle-brain-3~$rosrun image_view image_view image:=/camera/image _image_transport:=compressed

Additionally. if you wish to reproduce audio using Erle-Brain 3, attach the jack connector as in the image below:

By default the audio output is via HDMI

erle@erle-brain-3~$sudo apt-get install alsa-utils mpg321 lame -y

erle@erle-brain-3~$sudo modprobe snd-bcm2835

erle@erle-brain-3~$sudo amixer cset numid=3 1

erle@erle-brain-3~$sudo amixer cset numid=1 -- xxx%
erle@erle-brain-3~$sudo amixer cset numid=1 -- 80%

erle@erle-brain-3~$sudo apt-get install gnustep-gui-runtime
erle@erle-brain-3~$sudo say "hello"

wav files:

erle@erle-brain-3~$sudo aplay erle.wav

mp3 files:

erle@erle-brain-3~$sudo mpg321 "erle.mp3"